This study showed that various rhizosphere bacteria producing the enzyme 1-aminocyclopropane-1-ca... more This study showed that various rhizosphere bacteria producing the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCD), which can degrade ACC, the immediate precursor of ethylene in plants, and thereby lower plant ethylene levels, can act as promising biocontrol agents of pathogenic strains of Agrobacterium tumefaciens and A. vitis. Soaking the roots of tomato (Solanum lycopersicum) seedlings in a suspension of the ACCD-producing Pseudomonas putida UW4, Burkholderia phytofirmans PsJN or Azospirillum brasilense Cd1843 transformed by plasmid pRKTACC carrying the ACCD-encoding gene acdS from UW4, significantly reduced the development of tumours on tomato plants injected 4-5 days later with pathogenic Agrobacterium strains via wounds on the plant stem. The fresh mass of tumours formed by plants pretreated with ACCD-producing strains was typically four-to fivefold less than that of tumours formed on control plants inoculated only with a pathogenic Agrobacterium strain. Simultaneously, the level of ethylene evolution per amount of tumour mass on plants pretreated with ACCD-producing bacteria decreased four to eight times compared with that from tumours formed on control plants or plants pretreated with bacteria deficient in ACCD production. Moreover, transgenic tomato plants expressing a bacterial ACCD were found to be highly resistant to crown gall formation relative to the parental, non-transformed tomato plants. The results support the hypothesis that ethylene is a crucial factor in Agrobacterium tumour formation, and that ACCD-produced rhizosphere bacteria may protect plants infected by pathogenic Agrobacteria from crown gall disease.
Mango fruits (Mangifera indica L. cv. Nam Dokmai) were held for 3 days at 38°C and then transferr... more Mango fruits (Mangifera indica L. cv. Nam Dokmai) were held for 3 days at 38°C and then transferred to 20°C. Fruits placed directly at 25°C after harvest reached their peak ethylene production after 4 days, while the heated fruit took 9 days (6 days after the end of the heat treatment). The 1-aminocyclopropane-1-carboxylic acid (ACC) content paralleled that of ethylene production in unheated fruits, with highest content occurring on day 4. In heated fruit, ACC content continued to increase for 8 days following the heat treatment. The 1-aminocyclopropane-1-carboxylic acid synthase (ACS) activity in unheated fruit was also highest on day 4. In heated fruit the activity was undetectable following heat treatment, but recovered partially during the ripening period. Initial ethylene production from discs with peel was 6-fold higher in unheated fruit than heated, although after 6 h of incubation the production from both was similar. Activity of 1-aminocyclopropane-carboxylic acid oxidase (ACO) in the discs also showed an 8-fold difference in initial activity in heated versus unheated discs with peel. This difference disappeared during incubation of the discs. In heated discs without peel, both ethylene and ACO activity remained lower than in discs with peel, and the differences between heated and unheated fruit discs were more pronounced. We conclude that the inhibition of ethylene production found during heat treatment is due to inhibition of both ACS and ACO. ACO recovers full activity following heat, while ACS activity recovers only partially, but enough to allow the heated fruit to achieve an ethylene peak.
Single nucleotide polymorphisms (SNPs) were
used to construct an integrated SNP linkage map of pe... more Single nucleotide polymorphisms (SNPs) were used to construct an integrated SNP linkage map of peach (Prunus persica (L.) Batsch). A set of 1,536 SNPs were evaluated with the GoldenGate® Genotyping assay in two mapping populations, Pop-DF, and Pop-DG. After genotyping and filtering, a final set of 1,400 high quality SNPs in Pop-DF and 962 in Pop-DG with full map coverage were selected and used to construct two linkage maps with Join- Map®4.0. The Pop-DF map covered 422 cM of the peach genome and included 1,037 SNP markers, and Pop-DG map covered 369 cM and included 738 SNPs. A consensus map was constructed with 588 SNP markers placed in eight linkage groups (n08 for peach), with map coverage of 454 cM and an average distance of 0.81 cM/marker site. Placements of SNPs on the “peach v1.0” physical map were compared to placement on the linkage maps and several differences were observed. Using the SNP linkage map of Pop-DG and phenotypic data collected for three harvest seasons, a QTL analysis for fruit quality traits and chilling injury symptoms was carried out with the mapped SNPs. Significant QTL effects were detected for mealiness (M) and flesh bleeding (FBL) QTLs on linkage group 4 and flesh browning (FBr) on linkage group 5. This study represents one of the first examples of QTL detection for quality traits and chilling injury symptoms using a high-density SNP map in a single peach F1 family.
‘Crimson Seedless’ is a red, seedless table grape (Vitis vinifera) variety which may not develop ... more ‘Crimson Seedless’ is a red, seedless table grape (Vitis vinifera) variety which may not develop adequate colour during hot weather.This problem can be alleviated, in part, by applying abscisic acid (ABA).We were interested to determine whether a gibberellin (GA3), which is used to improve the size of grape berries, might interfere with this response.We were also interested in examining whether short periods of high temperature would affect the response to ABA. In addition, we assessed the optimum time at which to apply ABA, and the role of ethylene in berry colour development. These experiments were conducted in commercial vineyards in Israel, and on detached berries held under controlled conditions.GA3 had no effect on the response to ABA.There was a mixed response to ethylene, and to the application of ethylene inhibitors in the vineyard or in controlled studies in growth chambers.The best response in terms of colour development (i.e., anthocyanin levels) on detached berries occurred when 200 mg l–1ABA was applied in early August. A short period of high temperature did not affect the response to ABA, with similar accumulations of anthocyanins at 18ºC, 25ºC, or 38ºC for 24 h after ABA was applied. These results indicate that: (i) the practice of applying a GA3 spray to increase berry size did not affect the berry response to ABA; (ii) the responsiveness of grape berries to ABA was maintained for an extended time after the initiation of veraison; (iii) a period of high temperature after the application of ABA did not compromise the response of detached berries to ABA; and (iv) the response of berries to ethylene was not maintained after harvest. The best treatment to enhance colour in ‘Crimson Seedless’ grapes was therefore 200 – 400 mg l–1 ABA applied 2 – 3 weeks after veraison.
Gene expression at harvest was compared for
two stone fruit cultivars, a peach and its near-isoge... more Gene expression at harvest was compared for two stone fruit cultivars, a peach and its near-isogenic nectarine mutant, using two microarray platforms, μPEACH1.0 and ChillPeach. Together, both platforms covered over 6,000 genes out of which 417 were differentially expressed between the fruits of the two cultivars at a p value of 0.05. A total of 47 genes in nectarine and 60 genes in peach were at least twofold higher relative to each other. Nectarine had much better storage characteristics than peach and could be stored for over 5 weeks at 5 °C without storage disorders. In an attempt to determine whether gene expression at harvest could give an indication of storage potential, the expression analysis of the two cultivars was compared to that of two genotypes with different sensitivities to chilling injury. Principal component analysis of gene expression results across four fruit types differing in chilling sensitivity resulted in 41 genes whose expression levels separated the fruits according to sensitivity to storage disorders, suggesting that the genes have a role in cold response adaptation.
Worldwide pomegranate (Punica granatum L.) production has expanded greatly due to recent evidence... more Worldwide pomegranate (Punica granatum L.) production has expanded greatly due to recent evidence on the fruit health attributes. The fruit's unique red color, conferred by anthocyanins, is an imperative sensory quality. Climate effects on the fruit's internal color were reported earlier. The present study investigated the influence of a wide range of temperature regimes (∼7À40°C) on pomegranates' aril anthocyanins. The study included two deciduous and two evergreen accessions as well as desert and Mediterranean orchards. RP-HPLC analysis of the arils' anthocyanins revealed mono-and diglucosylated delphinidins and cyanidins as the major anthocyanins and pelargonidins as minor components. Anthocyanin accumulation changed inversely to the season's temperatures. Cyanidins were generally more abundant but delphinidin accumulation was enhanced in cooler season. Monoglucosylated anthocyanins prevailed at cooler temperatures and subsided during seasonal warming with a concomitant increase in diglucoside proportion. The findings can benefit breeding and agricultural efforts to enhance pomegranate quality, especially in the face of "global warming".
Journal of Horticultural Science and Biotechnology
Journal of Horticultura! Science & Biotechnology (1999) 74 (6) 685-689 Firmness, pectin c... more Journal of Horticultura! Science & Biotechnology (1999) 74 (6) 685-689 Firmness, pectin components and cell wall hydrolases of mango fruit following low-temperature stress By SAICHOL KETSA1*, SUGUNYA CHIDTRAGOOL2, JOSHUA D. KLEIN3 and SUSAN LURIE4 1 ...
Journal of the American Society for Horticultural Science. American Society for Horticultural Science
ADDITIONAL INDEX WORDS. chilling injury, polygalacturonase, pectin esterase, Prunus persica, β-1,... more ADDITIONAL INDEX WORDS. chilling injury, polygalacturonase, pectin esterase, Prunus persica, β-1,4-glucanase ABSTRACT. Most 'Flavortop' nectarines [Prunus persica (L.) Batsch (Nectarine Group)] that were placed directly into 0 °C storage developed chilling injury after removal, while preconditioning fruit for 2 days at 20 °C (delayed storage) reduced chilling injury substantially. Chilling injury was expressed as the development of a dry, woolly flesh texture during ripening. Delayed-storage fruit were as firm as control fruit when placed in storage, but softened more during storage. Analysis of cell wall components showed that in woolly fruit a higher percentage of pectin was retained in the sodium carbonate fraction, although during ripening polymers in this fraction decreased in molecular mass (Mr). In the guanidine thiocyanate hemicellulose fraction of woolly fruit, the associated pectin and hemicellulose remained as large polymers, while in delayedstorage fruit they decreased in Mr during ripening. Endo-polygalacturonase (PG), pectin esterase (PE), and endo-glucanase (EGase) activities of delayed-storage fruit were the same as control fruit at the beginning of storage, although exo-PG was higher. However, differences were observed at the end of storage. Endo-PG activity was lower in control than delayed-storage fruit at the end of storage while PE activity was higher, and exo-PG and EGase activities were similar. These differences in activity were not reflected in the mRNA abundance of the respective enzymes. Endo-PG and PE message was similar in all fruit at the end of storage and increased during ripening, while EGase message was low at all times except in control fruit after storage and development of woolliness. Prevention of chilling injury by delayed storage appears to be due to the ability of the fruit to continue a progressive, slow cell wall degradation in storage which allows normal ripening to proceed when the fruit are rewarmed. Regulation of the softening process did not appear to be by enzyme synthesis, since mRNA levels of the enzymes did not correspond with enzyme activity.
Journal of the American Society for Horticultural Science. American Society for Horticultural Science
Harvested nectarine fruit [Prunus persica (L.) Batsch 'Flavortop'] were held for 5 days at 20 °C,... more Harvested nectarine fruit [Prunus persica (L.) Batsch 'Flavortop'] were held for 5 days at 20 °C, or stored at 0 °C either immediately (control), or after 2 days at 20 °C (delayed-cooling). Observations were conducted after removal from storage for 1, 3, or 5 weeks and a shelf life of 5 additional days at 20 °C. After 5 weeks storage, 87% of control fruit developed woolliness (mealiness in texture accompanied by dry tasting fruit as a result of reduced juice content), while only 7% of delayed-cooling fruit showed signs of woolliness. Firmness of fruit in the delayed-cooling treatment was less at the beginning of ripening than control fruit, but after shelf life in both treatments, fruit reached the same final softness. Expressible juice was lower in woolly fruit (46%) than in healthy fruit (65%). Along with woolliness, viscosity of the resuspended alcohol insoluble residue (cell wall material) of expressed juice increased, implying accumulation of large molecular-weight polymers. The high performance liquid chromatography profile confirmed there were more large pectin polymers (2000 to 76 Ku) in the cell wall components of juice from woolly fruit and a lower arabinose content in these polymers reflected greater side chain removal from pectins in the juice of woolly fruit. Accumulation of larger sized pectin polymers along with high viscosity correlated with lower polygalacturonase activity in woolly fruit. Degradation of soluble pectin released into the juice of woolly fruit may have been impeded by repressed polygalacturonase activity.
Two main methods are in use for packing table grapes (Vitis vinifera) for refrigerated storage an... more Two main methods are in use for packing table grapes (Vitis vinifera) for refrigerated storage and transport. One is to pack the grapes with a sulfur dioxide (SO 2 ) generator pad inside a box with a perforated plastic liner and then to cool them. The other is to place the SO 2 pad on the grapes, cool the pallet, and wrap it with low-density polyethylene film, leaving the bottom of the pallet open. These two methods were compared for their efficiency in maintaining grape quality and preventing decay for periods ranging from 33 to 117 days. The experiments included 'Redglobe' and 'Zainy' grapes packaged in plastic boxes and 'Thompson Seedless' grapes packaged in cardboard boxes. The quality of the grapes in the trials with plastic boxes was either similar in both packaging methods or better in the wrapped pallet than the liner method. The pedicels, and sometimes the rachis, showed more desiccation in the liners than in the wrapped pallets. Prevention of decay was also better with the wrapped pallets than for storage in liners. However, in the experiment with cardboard boxes, the externally wrapped boxes contained lower levels of SO 2 , probably because of absorption of SO 2 by the cardboard, and the grapes developed more decay and rachis desiccation than in liners inside the cardboard boxes. The method of wrapping grapes after cooling them can have significant advantages over the liner method because of the faster cooling of the grapes and the use of less plastic-based, nonrecyclable materials.
Sweet bell pepper (Capsicum annuum L.) is a subtropical fruit. It is chilling-sensitive when stor... more Sweet bell pepper (Capsicum annuum L.) is a subtropical fruit. It is chilling-sensitive when stored at temperatures below 7°C for more than a week, while exported peppers are required to undergo a quarantine treat-ment of 3 weeks at 1.5°C against fruit fly which exacerbates chilling injury. Physical treatments to prevent chill-ing injury were investigated together with storage at 1.5°C to develop a successful quarantine protocol. The treat-ments, given both separately and in combination, were a hot water rinse (55°C for 15 s) over brushes (HWRB), and sealing each fruit in individual shrink packaging (Cryovac ®). Data from two research seasons indicated that the combined treatment maintained the best fruit quality. This was evidenced by lower decay incidence, due to the HWRB, and almost no chilling injury due to the individual shrink packaging. Reduction in chilling injury was associated with a significant reduction in membrane leakage and lipoxygenase activity, and the induction of ...
This study showed that various rhizosphere bacteria producing the enzyme 1-aminocyclopropane-1-ca... more This study showed that various rhizosphere bacteria producing the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCD), which can degrade ACC, the immediate precursor of ethylene in plants, and thereby lower plant ethylene levels, can act as promising biocontrol agents of pathogenic strains of Agrobacterium tumefaciens and A. vitis. Soaking the roots of tomato (Solanum lycopersicum) seedlings in a suspension of the ACCD-producing Pseudomonas putida UW4, Burkholderia phytofirmans PsJN or Azospirillum brasilense Cd1843 transformed by plasmid pRKTACC carrying the ACCD-encoding gene acdS from UW4, significantly reduced the development of tumours on tomato plants injected 4–5 days later with pathogenic Agrobacterium strains via wounds on the plant stem. The fresh mass of tumours formed by plants pretreated with ACCD-producing strains was typically four- to fivefold less than that of tumours formed on control plants inoculated only with a pathogenic Agrobacterium strain. Simult...
The fungus Botrytis cinerea is the major cause of decay in table grapes during storage, and the s... more The fungus Botrytis cinerea is the major cause of decay in table grapes during storage, and the severity of decay depends in part on contamination with the fungus before storage. The current SO 2 technology to prevent decay is robust and independent of the level of contamination by B. cinerea. The introduction of alternative technologies may however require implementation of means which are proportional to the level of contamination. The objectives of this study were to test the feasibility of quantifying B. cinerea in artificially inoculated grapes and to monitor the progress of disease during storage. Two methods were compared for detection of B. cinerea in grapes; an antibody kit specific for B. cinerea, and quantitative PCR using fungal specific primers. Antibodies for fast detection of B. cinerea yielded positive results only in the later stages of decay development. In contrast, the quantitative PCR demonstrated positive identification of the fungus at all storage time points, and found increasing amounts of the fungus during storage.
Temperature manipulations of harvested mature green tomatoes (Lycopersicon esculentum cv. Daniell... more Temperature manipulations of harvested mature green tomatoes (Lycopersicon esculentum cv. Daniella) were found to decrease chilling injury (CI) development if applied before 2°C storage. The tomatoes developed Cl after transfer to 20°C if held for longer than 1 week at 2°C. Gradual cooling to the storage temperature of 2°C prevented injury from developing.
A study was made of the effect of hot water dips (HWD) at temperatures of 42, 44, 46 and 48 8C (H... more A study was made of the effect of hot water dips (HWD) at temperatures of 42, 44, 46 and 48 8C (HWD 42 8C, HWD 44 8C, HWD 46 8C and HWD 48 8C, respectively) for 3 min on development of superficial scald and the concentration of a-farnesene and conjugated trienols (CT), CT 259 , CT 269 , CT 281 , as well as OD 200 on Granny Smith apple fruits harvested on three dates and stored 125 days in air at 2 8C. HWD 48 8C efficiently decreased surface scald in the second and third harvest. a-Farnesene and CT were measured spectrophotometrically and by HPLC. No clear relationship of OD 200 and scald development was observed. Correlation of scald index and OD 200 at the end of storage was negative for the second harvest date. There was no significant correlation between the scald index and CT 259 . Scald index was positively correlated with CT 269 after 80 days for the second and third harvest and at the end of storage for the second harvest. CT 281 was spectrophotometrically detectable only at the end of the storage, for the third harvest date, in control, HWD 42 8C, and HWD 44 8C. HWD 42 8C had significantly higher CT 281 compared to HWD 44 8C and control. HPLC analysis of control samples revealed presence of CT 281 in all three harvest dates, and presence of at least two components, as was the case of CT 259 and CT 269 . The ratio of these two components was different for all three CT species. Fruit maturity was an important factor determining the response of fruit to heat and occurrence of superficial scald. The results indicate that a successful treatment using HWD to control superficial scald may be obtained after further research and that there are still some questions on the role of different CT's in scald biochemistry that should be addressed in future research. #
This study showed that various rhizosphere bacteria producing the enzyme 1-aminocyclopropane-1-ca... more This study showed that various rhizosphere bacteria producing the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCD), which can degrade ACC, the immediate precursor of ethylene in plants, and thereby lower plant ethylene levels, can act as promising biocontrol agents of pathogenic strains of Agrobacterium tumefaciens and A. vitis. Soaking the roots of tomato (Solanum lycopersicum) seedlings in a suspension of the ACCD-producing Pseudomonas putida UW4, Burkholderia phytofirmans PsJN or Azospirillum brasilense Cd1843 transformed by plasmid pRKTACC carrying the ACCD-encoding gene acdS from UW4, significantly reduced the development of tumours on tomato plants injected 4-5 days later with pathogenic Agrobacterium strains via wounds on the plant stem. The fresh mass of tumours formed by plants pretreated with ACCD-producing strains was typically four-to fivefold less than that of tumours formed on control plants inoculated only with a pathogenic Agrobacterium strain. Simultaneously, the level of ethylene evolution per amount of tumour mass on plants pretreated with ACCD-producing bacteria decreased four to eight times compared with that from tumours formed on control plants or plants pretreated with bacteria deficient in ACCD production. Moreover, transgenic tomato plants expressing a bacterial ACCD were found to be highly resistant to crown gall formation relative to the parental, non-transformed tomato plants. The results support the hypothesis that ethylene is a crucial factor in Agrobacterium tumour formation, and that ACCD-produced rhizosphere bacteria may protect plants infected by pathogenic Agrobacteria from crown gall disease.
Mango fruits (Mangifera indica L. cv. Nam Dokmai) were held for 3 days at 38°C and then transferr... more Mango fruits (Mangifera indica L. cv. Nam Dokmai) were held for 3 days at 38°C and then transferred to 20°C. Fruits placed directly at 25°C after harvest reached their peak ethylene production after 4 days, while the heated fruit took 9 days (6 days after the end of the heat treatment). The 1-aminocyclopropane-1-carboxylic acid (ACC) content paralleled that of ethylene production in unheated fruits, with highest content occurring on day 4. In heated fruit, ACC content continued to increase for 8 days following the heat treatment. The 1-aminocyclopropane-1-carboxylic acid synthase (ACS) activity in unheated fruit was also highest on day 4. In heated fruit the activity was undetectable following heat treatment, but recovered partially during the ripening period. Initial ethylene production from discs with peel was 6-fold higher in unheated fruit than heated, although after 6 h of incubation the production from both was similar. Activity of 1-aminocyclopropane-carboxylic acid oxidase (ACO) in the discs also showed an 8-fold difference in initial activity in heated versus unheated discs with peel. This difference disappeared during incubation of the discs. In heated discs without peel, both ethylene and ACO activity remained lower than in discs with peel, and the differences between heated and unheated fruit discs were more pronounced. We conclude that the inhibition of ethylene production found during heat treatment is due to inhibition of both ACS and ACO. ACO recovers full activity following heat, while ACS activity recovers only partially, but enough to allow the heated fruit to achieve an ethylene peak.
Single nucleotide polymorphisms (SNPs) were
used to construct an integrated SNP linkage map of pe... more Single nucleotide polymorphisms (SNPs) were used to construct an integrated SNP linkage map of peach (Prunus persica (L.) Batsch). A set of 1,536 SNPs were evaluated with the GoldenGate® Genotyping assay in two mapping populations, Pop-DF, and Pop-DG. After genotyping and filtering, a final set of 1,400 high quality SNPs in Pop-DF and 962 in Pop-DG with full map coverage were selected and used to construct two linkage maps with Join- Map®4.0. The Pop-DF map covered 422 cM of the peach genome and included 1,037 SNP markers, and Pop-DG map covered 369 cM and included 738 SNPs. A consensus map was constructed with 588 SNP markers placed in eight linkage groups (n08 for peach), with map coverage of 454 cM and an average distance of 0.81 cM/marker site. Placements of SNPs on the “peach v1.0” physical map were compared to placement on the linkage maps and several differences were observed. Using the SNP linkage map of Pop-DG and phenotypic data collected for three harvest seasons, a QTL analysis for fruit quality traits and chilling injury symptoms was carried out with the mapped SNPs. Significant QTL effects were detected for mealiness (M) and flesh bleeding (FBL) QTLs on linkage group 4 and flesh browning (FBr) on linkage group 5. This study represents one of the first examples of QTL detection for quality traits and chilling injury symptoms using a high-density SNP map in a single peach F1 family.
‘Crimson Seedless’ is a red, seedless table grape (Vitis vinifera) variety which may not develop ... more ‘Crimson Seedless’ is a red, seedless table grape (Vitis vinifera) variety which may not develop adequate colour during hot weather.This problem can be alleviated, in part, by applying abscisic acid (ABA).We were interested to determine whether a gibberellin (GA3), which is used to improve the size of grape berries, might interfere with this response.We were also interested in examining whether short periods of high temperature would affect the response to ABA. In addition, we assessed the optimum time at which to apply ABA, and the role of ethylene in berry colour development. These experiments were conducted in commercial vineyards in Israel, and on detached berries held under controlled conditions.GA3 had no effect on the response to ABA.There was a mixed response to ethylene, and to the application of ethylene inhibitors in the vineyard or in controlled studies in growth chambers.The best response in terms of colour development (i.e., anthocyanin levels) on detached berries occurred when 200 mg l–1ABA was applied in early August. A short period of high temperature did not affect the response to ABA, with similar accumulations of anthocyanins at 18ºC, 25ºC, or 38ºC for 24 h after ABA was applied. These results indicate that: (i) the practice of applying a GA3 spray to increase berry size did not affect the berry response to ABA; (ii) the responsiveness of grape berries to ABA was maintained for an extended time after the initiation of veraison; (iii) a period of high temperature after the application of ABA did not compromise the response of detached berries to ABA; and (iv) the response of berries to ethylene was not maintained after harvest. The best treatment to enhance colour in ‘Crimson Seedless’ grapes was therefore 200 – 400 mg l–1 ABA applied 2 – 3 weeks after veraison.
Gene expression at harvest was compared for
two stone fruit cultivars, a peach and its near-isoge... more Gene expression at harvest was compared for two stone fruit cultivars, a peach and its near-isogenic nectarine mutant, using two microarray platforms, μPEACH1.0 and ChillPeach. Together, both platforms covered over 6,000 genes out of which 417 were differentially expressed between the fruits of the two cultivars at a p value of 0.05. A total of 47 genes in nectarine and 60 genes in peach were at least twofold higher relative to each other. Nectarine had much better storage characteristics than peach and could be stored for over 5 weeks at 5 °C without storage disorders. In an attempt to determine whether gene expression at harvest could give an indication of storage potential, the expression analysis of the two cultivars was compared to that of two genotypes with different sensitivities to chilling injury. Principal component analysis of gene expression results across four fruit types differing in chilling sensitivity resulted in 41 genes whose expression levels separated the fruits according to sensitivity to storage disorders, suggesting that the genes have a role in cold response adaptation.
Worldwide pomegranate (Punica granatum L.) production has expanded greatly due to recent evidence... more Worldwide pomegranate (Punica granatum L.) production has expanded greatly due to recent evidence on the fruit health attributes. The fruit's unique red color, conferred by anthocyanins, is an imperative sensory quality. Climate effects on the fruit's internal color were reported earlier. The present study investigated the influence of a wide range of temperature regimes (∼7À40°C) on pomegranates' aril anthocyanins. The study included two deciduous and two evergreen accessions as well as desert and Mediterranean orchards. RP-HPLC analysis of the arils' anthocyanins revealed mono-and diglucosylated delphinidins and cyanidins as the major anthocyanins and pelargonidins as minor components. Anthocyanin accumulation changed inversely to the season's temperatures. Cyanidins were generally more abundant but delphinidin accumulation was enhanced in cooler season. Monoglucosylated anthocyanins prevailed at cooler temperatures and subsided during seasonal warming with a concomitant increase in diglucoside proportion. The findings can benefit breeding and agricultural efforts to enhance pomegranate quality, especially in the face of "global warming".
Journal of Horticultural Science and Biotechnology
Journal of Horticultura! Science & Biotechnology (1999) 74 (6) 685-689 Firmness, pectin c... more Journal of Horticultura! Science & Biotechnology (1999) 74 (6) 685-689 Firmness, pectin components and cell wall hydrolases of mango fruit following low-temperature stress By SAICHOL KETSA1*, SUGUNYA CHIDTRAGOOL2, JOSHUA D. KLEIN3 and SUSAN LURIE4 1 ...
Journal of the American Society for Horticultural Science. American Society for Horticultural Science
ADDITIONAL INDEX WORDS. chilling injury, polygalacturonase, pectin esterase, Prunus persica, β-1,... more ADDITIONAL INDEX WORDS. chilling injury, polygalacturonase, pectin esterase, Prunus persica, β-1,4-glucanase ABSTRACT. Most 'Flavortop' nectarines [Prunus persica (L.) Batsch (Nectarine Group)] that were placed directly into 0 °C storage developed chilling injury after removal, while preconditioning fruit for 2 days at 20 °C (delayed storage) reduced chilling injury substantially. Chilling injury was expressed as the development of a dry, woolly flesh texture during ripening. Delayed-storage fruit were as firm as control fruit when placed in storage, but softened more during storage. Analysis of cell wall components showed that in woolly fruit a higher percentage of pectin was retained in the sodium carbonate fraction, although during ripening polymers in this fraction decreased in molecular mass (Mr). In the guanidine thiocyanate hemicellulose fraction of woolly fruit, the associated pectin and hemicellulose remained as large polymers, while in delayedstorage fruit they decreased in Mr during ripening. Endo-polygalacturonase (PG), pectin esterase (PE), and endo-glucanase (EGase) activities of delayed-storage fruit were the same as control fruit at the beginning of storage, although exo-PG was higher. However, differences were observed at the end of storage. Endo-PG activity was lower in control than delayed-storage fruit at the end of storage while PE activity was higher, and exo-PG and EGase activities were similar. These differences in activity were not reflected in the mRNA abundance of the respective enzymes. Endo-PG and PE message was similar in all fruit at the end of storage and increased during ripening, while EGase message was low at all times except in control fruit after storage and development of woolliness. Prevention of chilling injury by delayed storage appears to be due to the ability of the fruit to continue a progressive, slow cell wall degradation in storage which allows normal ripening to proceed when the fruit are rewarmed. Regulation of the softening process did not appear to be by enzyme synthesis, since mRNA levels of the enzymes did not correspond with enzyme activity.
Journal of the American Society for Horticultural Science. American Society for Horticultural Science
Harvested nectarine fruit [Prunus persica (L.) Batsch 'Flavortop'] were held for 5 days at 20 °C,... more Harvested nectarine fruit [Prunus persica (L.) Batsch 'Flavortop'] were held for 5 days at 20 °C, or stored at 0 °C either immediately (control), or after 2 days at 20 °C (delayed-cooling). Observations were conducted after removal from storage for 1, 3, or 5 weeks and a shelf life of 5 additional days at 20 °C. After 5 weeks storage, 87% of control fruit developed woolliness (mealiness in texture accompanied by dry tasting fruit as a result of reduced juice content), while only 7% of delayed-cooling fruit showed signs of woolliness. Firmness of fruit in the delayed-cooling treatment was less at the beginning of ripening than control fruit, but after shelf life in both treatments, fruit reached the same final softness. Expressible juice was lower in woolly fruit (46%) than in healthy fruit (65%). Along with woolliness, viscosity of the resuspended alcohol insoluble residue (cell wall material) of expressed juice increased, implying accumulation of large molecular-weight polymers. The high performance liquid chromatography profile confirmed there were more large pectin polymers (2000 to 76 Ku) in the cell wall components of juice from woolly fruit and a lower arabinose content in these polymers reflected greater side chain removal from pectins in the juice of woolly fruit. Accumulation of larger sized pectin polymers along with high viscosity correlated with lower polygalacturonase activity in woolly fruit. Degradation of soluble pectin released into the juice of woolly fruit may have been impeded by repressed polygalacturonase activity.
Two main methods are in use for packing table grapes (Vitis vinifera) for refrigerated storage an... more Two main methods are in use for packing table grapes (Vitis vinifera) for refrigerated storage and transport. One is to pack the grapes with a sulfur dioxide (SO 2 ) generator pad inside a box with a perforated plastic liner and then to cool them. The other is to place the SO 2 pad on the grapes, cool the pallet, and wrap it with low-density polyethylene film, leaving the bottom of the pallet open. These two methods were compared for their efficiency in maintaining grape quality and preventing decay for periods ranging from 33 to 117 days. The experiments included 'Redglobe' and 'Zainy' grapes packaged in plastic boxes and 'Thompson Seedless' grapes packaged in cardboard boxes. The quality of the grapes in the trials with plastic boxes was either similar in both packaging methods or better in the wrapped pallet than the liner method. The pedicels, and sometimes the rachis, showed more desiccation in the liners than in the wrapped pallets. Prevention of decay was also better with the wrapped pallets than for storage in liners. However, in the experiment with cardboard boxes, the externally wrapped boxes contained lower levels of SO 2 , probably because of absorption of SO 2 by the cardboard, and the grapes developed more decay and rachis desiccation than in liners inside the cardboard boxes. The method of wrapping grapes after cooling them can have significant advantages over the liner method because of the faster cooling of the grapes and the use of less plastic-based, nonrecyclable materials.
Sweet bell pepper (Capsicum annuum L.) is a subtropical fruit. It is chilling-sensitive when stor... more Sweet bell pepper (Capsicum annuum L.) is a subtropical fruit. It is chilling-sensitive when stored at temperatures below 7°C for more than a week, while exported peppers are required to undergo a quarantine treat-ment of 3 weeks at 1.5°C against fruit fly which exacerbates chilling injury. Physical treatments to prevent chill-ing injury were investigated together with storage at 1.5°C to develop a successful quarantine protocol. The treat-ments, given both separately and in combination, were a hot water rinse (55°C for 15 s) over brushes (HWRB), and sealing each fruit in individual shrink packaging (Cryovac ®). Data from two research seasons indicated that the combined treatment maintained the best fruit quality. This was evidenced by lower decay incidence, due to the HWRB, and almost no chilling injury due to the individual shrink packaging. Reduction in chilling injury was associated with a significant reduction in membrane leakage and lipoxygenase activity, and the induction of ...
This study showed that various rhizosphere bacteria producing the enzyme 1-aminocyclopropane-1-ca... more This study showed that various rhizosphere bacteria producing the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCD), which can degrade ACC, the immediate precursor of ethylene in plants, and thereby lower plant ethylene levels, can act as promising biocontrol agents of pathogenic strains of Agrobacterium tumefaciens and A. vitis. Soaking the roots of tomato (Solanum lycopersicum) seedlings in a suspension of the ACCD-producing Pseudomonas putida UW4, Burkholderia phytofirmans PsJN or Azospirillum brasilense Cd1843 transformed by plasmid pRKTACC carrying the ACCD-encoding gene acdS from UW4, significantly reduced the development of tumours on tomato plants injected 4–5 days later with pathogenic Agrobacterium strains via wounds on the plant stem. The fresh mass of tumours formed by plants pretreated with ACCD-producing strains was typically four- to fivefold less than that of tumours formed on control plants inoculated only with a pathogenic Agrobacterium strain. Simult...
The fungus Botrytis cinerea is the major cause of decay in table grapes during storage, and the s... more The fungus Botrytis cinerea is the major cause of decay in table grapes during storage, and the severity of decay depends in part on contamination with the fungus before storage. The current SO 2 technology to prevent decay is robust and independent of the level of contamination by B. cinerea. The introduction of alternative technologies may however require implementation of means which are proportional to the level of contamination. The objectives of this study were to test the feasibility of quantifying B. cinerea in artificially inoculated grapes and to monitor the progress of disease during storage. Two methods were compared for detection of B. cinerea in grapes; an antibody kit specific for B. cinerea, and quantitative PCR using fungal specific primers. Antibodies for fast detection of B. cinerea yielded positive results only in the later stages of decay development. In contrast, the quantitative PCR demonstrated positive identification of the fungus at all storage time points, and found increasing amounts of the fungus during storage.
Temperature manipulations of harvested mature green tomatoes (Lycopersicon esculentum cv. Daniell... more Temperature manipulations of harvested mature green tomatoes (Lycopersicon esculentum cv. Daniella) were found to decrease chilling injury (CI) development if applied before 2°C storage. The tomatoes developed Cl after transfer to 20°C if held for longer than 1 week at 2°C. Gradual cooling to the storage temperature of 2°C prevented injury from developing.
A study was made of the effect of hot water dips (HWD) at temperatures of 42, 44, 46 and 48 8C (H... more A study was made of the effect of hot water dips (HWD) at temperatures of 42, 44, 46 and 48 8C (HWD 42 8C, HWD 44 8C, HWD 46 8C and HWD 48 8C, respectively) for 3 min on development of superficial scald and the concentration of a-farnesene and conjugated trienols (CT), CT 259 , CT 269 , CT 281 , as well as OD 200 on Granny Smith apple fruits harvested on three dates and stored 125 days in air at 2 8C. HWD 48 8C efficiently decreased surface scald in the second and third harvest. a-Farnesene and CT were measured spectrophotometrically and by HPLC. No clear relationship of OD 200 and scald development was observed. Correlation of scald index and OD 200 at the end of storage was negative for the second harvest date. There was no significant correlation between the scald index and CT 259 . Scald index was positively correlated with CT 269 after 80 days for the second and third harvest and at the end of storage for the second harvest. CT 281 was spectrophotometrically detectable only at the end of the storage, for the third harvest date, in control, HWD 42 8C, and HWD 44 8C. HWD 42 8C had significantly higher CT 281 compared to HWD 44 8C and control. HPLC analysis of control samples revealed presence of CT 281 in all three harvest dates, and presence of at least two components, as was the case of CT 259 and CT 269 . The ratio of these two components was different for all three CT species. Fruit maturity was an important factor determining the response of fruit to heat and occurrence of superficial scald. The results indicate that a successful treatment using HWD to control superficial scald may be obtained after further research and that there are still some questions on the role of different CT's in scald biochemistry that should be addressed in future research. #
Uploads
Papers by Susan Lurie
used to construct an integrated SNP linkage map of peach
(Prunus persica (L.) Batsch). A set of 1,536 SNPs were
evaluated with the GoldenGate® Genotyping assay in two
mapping populations, Pop-DF, and Pop-DG. After genotyping
and filtering, a final set of 1,400 high quality SNPs in
Pop-DF and 962 in Pop-DG with full map coverage were
selected and used to construct two linkage maps with Join-
Map®4.0. The Pop-DF map covered 422 cM of the peach
genome and included 1,037 SNP markers, and Pop-DG map
covered 369 cM and included 738 SNPs. A consensus map
was constructed with 588 SNP markers placed in eight
linkage groups (n08 for peach), with map coverage of 454 cM and an average distance of 0.81 cM/marker site.
Placements of SNPs on the “peach v1.0” physical map were
compared to placement on the linkage maps and several
differences were observed. Using the SNP linkage map of
Pop-DG and phenotypic data collected for three harvest
seasons, a QTL analysis for fruit quality traits and chilling
injury symptoms was carried out with the mapped SNPs.
Significant QTL effects were detected for mealiness (M) and
flesh bleeding (FBL) QTLs on linkage group 4 and flesh
browning (FBr) on linkage group 5. This study represents
one of the first examples of QTL detection for quality traits
and chilling injury symptoms using a high-density SNP map
in a single peach F1 family.
hot weather.This problem can be alleviated, in part, by applying abscisic acid (ABA).We were interested to determine
whether a gibberellin (GA3), which is used to improve the size of grape berries, might interfere with this response.We
were also interested in examining whether short periods of high temperature would affect the response to ABA. In
addition, we assessed the optimum time at which to apply ABA, and the role of ethylene in berry colour development.
These experiments were conducted in commercial vineyards in Israel, and on detached berries held under controlled
conditions.GA3 had no effect on the response to ABA.There was a mixed response to ethylene, and to the application
of ethylene inhibitors in the vineyard or in controlled studies in growth chambers.The best response in terms of colour
development (i.e., anthocyanin levels) on detached berries occurred when 200 mg l–1ABA was applied in early August.
A short period of high temperature did not affect the response to ABA, with similar accumulations of anthocyanins
at 18ºC, 25ºC, or 38ºC for 24 h after ABA was applied. These results indicate that: (i) the practice of applying a GA3
spray to increase berry size did not affect the berry response to ABA; (ii) the responsiveness of grape berries to ABA
was maintained for an extended time after the initiation of veraison; (iii) a period of high temperature after the
application of ABA did not compromise the response of detached berries to ABA; and (iv) the response of berries to
ethylene was not maintained after harvest. The best treatment to enhance colour in ‘Crimson Seedless’ grapes was
therefore 200 – 400 mg l–1 ABA applied 2 – 3 weeks after veraison.
two stone fruit cultivars, a peach and its near-isogenic
nectarine mutant, using two microarray platforms,
μPEACH1.0 and ChillPeach. Together, both platforms
covered over 6,000 genes out of which 417 were differentially
expressed between the fruits of the two cultivars
at a p value of 0.05. A total of 47 genes in nectarine and 60 genes in peach were at least twofold higher relative to
each other. Nectarine had much better storage characteristics
than peach and could be stored for over 5 weeks at
5 °C without storage disorders. In an attempt to determine
whether gene expression at harvest could give an indication
of storage potential, the expression analysis of the
two cultivars was compared to that of two genotypes with
different sensitivities to chilling injury. Principal component
analysis of gene expression results across four fruit
types differing in chilling sensitivity resulted in 41 genes
whose expression levels separated the fruits according to
sensitivity to storage disorders, suggesting that the genes
have a role in cold response adaptation.
used to construct an integrated SNP linkage map of peach
(Prunus persica (L.) Batsch). A set of 1,536 SNPs were
evaluated with the GoldenGate® Genotyping assay in two
mapping populations, Pop-DF, and Pop-DG. After genotyping
and filtering, a final set of 1,400 high quality SNPs in
Pop-DF and 962 in Pop-DG with full map coverage were
selected and used to construct two linkage maps with Join-
Map®4.0. The Pop-DF map covered 422 cM of the peach
genome and included 1,037 SNP markers, and Pop-DG map
covered 369 cM and included 738 SNPs. A consensus map
was constructed with 588 SNP markers placed in eight
linkage groups (n08 for peach), with map coverage of 454 cM and an average distance of 0.81 cM/marker site.
Placements of SNPs on the “peach v1.0” physical map were
compared to placement on the linkage maps and several
differences were observed. Using the SNP linkage map of
Pop-DG and phenotypic data collected for three harvest
seasons, a QTL analysis for fruit quality traits and chilling
injury symptoms was carried out with the mapped SNPs.
Significant QTL effects were detected for mealiness (M) and
flesh bleeding (FBL) QTLs on linkage group 4 and flesh
browning (FBr) on linkage group 5. This study represents
one of the first examples of QTL detection for quality traits
and chilling injury symptoms using a high-density SNP map
in a single peach F1 family.
hot weather.This problem can be alleviated, in part, by applying abscisic acid (ABA).We were interested to determine
whether a gibberellin (GA3), which is used to improve the size of grape berries, might interfere with this response.We
were also interested in examining whether short periods of high temperature would affect the response to ABA. In
addition, we assessed the optimum time at which to apply ABA, and the role of ethylene in berry colour development.
These experiments were conducted in commercial vineyards in Israel, and on detached berries held under controlled
conditions.GA3 had no effect on the response to ABA.There was a mixed response to ethylene, and to the application
of ethylene inhibitors in the vineyard or in controlled studies in growth chambers.The best response in terms of colour
development (i.e., anthocyanin levels) on detached berries occurred when 200 mg l–1ABA was applied in early August.
A short period of high temperature did not affect the response to ABA, with similar accumulations of anthocyanins
at 18ºC, 25ºC, or 38ºC for 24 h after ABA was applied. These results indicate that: (i) the practice of applying a GA3
spray to increase berry size did not affect the berry response to ABA; (ii) the responsiveness of grape berries to ABA
was maintained for an extended time after the initiation of veraison; (iii) a period of high temperature after the
application of ABA did not compromise the response of detached berries to ABA; and (iv) the response of berries to
ethylene was not maintained after harvest. The best treatment to enhance colour in ‘Crimson Seedless’ grapes was
therefore 200 – 400 mg l–1 ABA applied 2 – 3 weeks after veraison.
two stone fruit cultivars, a peach and its near-isogenic
nectarine mutant, using two microarray platforms,
μPEACH1.0 and ChillPeach. Together, both platforms
covered over 6,000 genes out of which 417 were differentially
expressed between the fruits of the two cultivars
at a p value of 0.05. A total of 47 genes in nectarine and 60 genes in peach were at least twofold higher relative to
each other. Nectarine had much better storage characteristics
than peach and could be stored for over 5 weeks at
5 °C without storage disorders. In an attempt to determine
whether gene expression at harvest could give an indication
of storage potential, the expression analysis of the
two cultivars was compared to that of two genotypes with
different sensitivities to chilling injury. Principal component
analysis of gene expression results across four fruit
types differing in chilling sensitivity resulted in 41 genes
whose expression levels separated the fruits according to
sensitivity to storage disorders, suggesting that the genes
have a role in cold response adaptation.