Papers by Latifa AL-Kharusi
CABI eBooks, Jun 14, 2023
International Journal of Agriculture and Biology, 2012
... Dates RASHID AL-YAHYAI 1 AND LATIFA AL-KHARUSI Department of Crop Sciences, College of Agricu... more ... Dates RASHID AL-YAHYAI 1 AND LATIFA AL-KHARUSI Department of Crop Sciences, College of Agricultural and Marine Sciences, Sultan Qaboos University, PO Box 34, Al-Khod 123, Oman 1Corresponding author's e-mail: [email protected] ABSTRACT ...
International Journal of Agriculture and Biology, 2010
... AHMED AL-MASKRI 1, LATIFA AL-KHARUSI, HANAN AL-MIQBALI AND M. MUMTAZ KHAN Department of Crop... more ... AHMED AL-MASKRI 1, LATIFA AL-KHARUSI, HANAN AL-MIQBALI AND M. MUMTAZ KHAN Department of Crop Sciences, College of ... 123, Oman WRC, Sultan Qaboos University, PO Box 34, Al-Khod, 123, Oman 1Corresponding author's e-mail: [email protected] ...
Acta horticulturae, Mar 1, 2007
Thirty date palms of each of Khalas and Khassab cultivars at 6-7 years of age were selected rando... more Thirty date palms of each of Khalas and Khassab cultivars at 6-7 years of age were selected randomly in Al-Fairooz Farm in Khabourah, Batina region. The aim was to improve fruit production and quality by fertilizer application. Experimental treatments were applied in a factorial design and included: organic peat alone with 1000g urea divided into 5 and 4 equal doses mixed with 500g triple superphosphate and 800g K 2 SO 4 and with or without micronutrients. The control included no organic or mineral fertilizer. Mineral fertilizer tended to increase Khassab strand weight and decrease fruit number. The highest number and yield was associated with the smallest length and diameter and was produced by NPK + micronutrients and organic peat. In Khalas no significant differences were observed in fruit number, weight and size, but NPK 5 or 4 nitrogen doses with micronutrients and organic peat produced the highest yield. Four nitrogen doses with phosphate and K 2 SO 4 increased Khalas yield by 22% over the control and 24.7% over organic peat. The same treatment increased Khassab yield by 77.5% over the control and 130% over organic peat. On the other hand, five nitrogen doses increased the yield of Khalas by 17.8% over the control and 20.4 % over organic peat. On Khassab it increased the yield by 63% over the control and 112.4% over peat. Five nitrogen doses in Khalas produced higher weight of strand, number of fruit per strand, weight and length of fruit and yield than 4 doses. It produced lower strand weight, fruit length and diameter, and higher yield and number of fruit per strand than 4 doses on Khassab. In both cultivars, number and weight of fruit/strand and weight of fruit were lower in Rutab than Bisir stage. However, diameter was reduced and yield was increased in Khassab, whereas in Khalas both fruit length and yield were reduced from Bisir to Rutab.
African Journal of Agricultural Research, Mar 12, 2012
Date palm (Phoenix dactylifera L.) is primarily cultivated in the regions of the Middle East and ... more Date palm (Phoenix dactylifera L.) is primarily cultivated in the regions of the Middle East and North Africa that are characterized by high evapotranspiration, low and sporadic rainfall and dependency on irrigation for crop cultivation. The effects of sub-optimal irrigation on the chemical properties of dates were investigated. Chemical quality attributes of date palm (cv. Khalas) grown in northern Oman showed variable responses to reduced frequency of irrigation water applied during fruit development. Trees irrigated on a daily basis showed a significantly higher fruit water content, juice volume, and titratable acidity (TA). Deficit irrigation treatments had the highest total-and reducing sugar content. Trees under water stress that were irrigated once per week showed significantly high dry matter, total soluble solids (TSS) and pectin. Sucrose, tannin and pH were not significantly different among irrigation treatments. Manipulation of irrigation frequency can be used to enhance certain chemical fruit quality attributes of dates.
Intratumoral upregulated reactive oxygen species (ROS) has been extensively exploited as exclusiv... more Intratumoral upregulated reactive oxygen species (ROS) has been extensively exploited as exclusive stimulus to activate drug release for tumor-specific therapy. However, insufficient endogenous ROS and tumor heterogeneity severely restrict clinical translation of current ROS-responsive drug delivery systems. Herein, a tailored ROS-activatable self-amplifying supramolecular nanoprodrug was developed for reinforced ROS-responsiveness and highly selective antitumor therapy. A novel ROS-cleavable CA-based thioacetal linker CASOH was synthesized with ROS generator cinnamaldehyde (CA) incorporated into its molecular structure, to skillfully realize self-amplifying positive feedback loop of "ROS-activated CA release with CA-induced ROS regeneration". CASOH was modified with a cytosine analogue gemcitabine (GEM) to obtain ROS-activatable self-immolative prodrug CAG, which could be selectively activated in tumor cells and further achieve self-boosting "snowballing" activation via ROS compensation, while keep inactive in normal cells. Through Watson-Crick nucleobase pairing (G≡C)-like hydrogen bonds, CAG efficiently crosslinked with a matched guanine-rich acyclovir-modified hyaluronic acid conjugate HA-ACV, to self-assemble into pH/ROS dual-responsive supramolecular nanoprodrug HCAG. With high stability, beneficial tumor targeting capacity and pH/ROS-responsiveness, HCAG nanoformulation exhibited remarkable in vivo antitumor efficacy with minimal systemic toxicity. Based on unique tumor-specific self-amplifying prodrug activation and Watson-Crick base pairing-inspired supramolecular self-assembly, this study provides an inspirational strategy of exploiting novel ROS-responsive nanoplatform with reinforced responsiveness and specificity for future clinical translation.
Plant Molecular Biology Reporter, 2020
Since specific metabolites may be associated with salinity tolerance, this study aimed to deciphe... more Since specific metabolites may be associated with salinity tolerance, this study aimed to decipher the salinity tolerance mechanism in date palm based on the information encoded by the metabolomic profiles of the salt-tolerant “Umsila” and salt-susceptible “Zabad” cultivars when grown under salinity conditions. Changes in the metabolomic profiles of the leaf and root tissues were determined using hydrophilic interaction liquid chromatography (HILIC) and reverse-phase liquid chromatography (RPLC) mass spectrometry. The global untargeted metabolomic analysis showed the presence of 4878 metabolites accumulated in leaf and root tissues of the date palm seedlings. Principal component analysis (PCA) revealed the presence of unique groups of metabolites for each treatment and tissue type. Pathway analysis showed the involvement of some of these metabolites in the biosynthesis of several types of membranous lipids and glycolipids molecules such as 18:0-lyso-phosphatidylethanolamine (lysoPE), and also the synthesis of cell-wall components such as 16-hydroxy hexadecanoic acid, which is an intermediate metabolite in cutin, suberin, and wax biosynthesis. Moreover, antioxidant flavonoids such as (+)-catechin and epicatechin, vitamins such as B9, phytohormone-associated compounds such as dihydrozeatin-9-N-glucoside-O-glucoside, and osmolytes such as the sulfonic amino acid taurine were all significantly (p ≤ 0.05, FWER ≤ 0.05) altered in response to salinity in both cultivars. These results indicate that salinity tolerance in date palm involved a multi-dimensional mechanism, which includes the modification of the cell-wall and cellular membranes, the production of oxygen species scavengers, the adjustment of cellular osmotic pressure, and probably the alteration of the hormonal balance. The intracultivar metabolomic profile comparison strategy performed in this study represents an approach that may pave the road toward the identification of salinity tolerance mechanisms in date palm based on the final protein products.
Plant Signaling & Behavior, 2019
Silicon is known to promote plant growth as well as stress tolerance of plants. The current study... more Silicon is known to promote plant growth as well as stress tolerance of plants. The current study was undertaken to assess the growth promoting effect of silicon on date palm seedling development as well as its ability to abate some of the negative effects of salinity. In this study, date palm seedlings were treated with silicon and sodium chloride salts, and the effect of these salts on some physiological parameters of the plants was determined. In addition, a global nontargeted metabolomics analysis was performed for the leaf and root tissues using liquid chromatography-mass spectrometry (LC-MS). The results showed that under non-stress conditions, silicon treatment enhanced the growth of the date palm seedlings, however, under salinity, silicon slightly mitigates the negative effects of salt stress on the date palm seedlings although it enhances the potassium accumulation under this condition. The global metabolomics analysis has identified a total of 1,101 significant differentially accumulated (p, q ≤ 0.05) metabolites in leaves and roots under silicon, salinity or their combination. A differential pairwise metabolic profile comparison revealed the accumulation of distinct metabolites in response to silicon and salinity treatments such as antioxidant compounds pyridoxine, cepharanthine, allithiamine, myristic acid and boldine; osmoregulators such as mucic acid; along with the accumulation of detoxification intermediates such as S-D-lactoylglutathione, beta-cyano-L-alanine and gamma-glutamyl-conjugates. In addition, histochemical analyses revealed that application of silicon significantly (p ≤ 0.05) enhanced the formation of the Casparian strip. Identification of the differentially accumulated metabolites could offer an insight into how silicon is able to promote growth and salinity tolerance in date palms.
International Journal of Molecular Sciences, 2019
Although the date palm tree is an extremophile with tolerance to drought and certain levels of sa... more Although the date palm tree is an extremophile with tolerance to drought and certain levels of salinity, the damage caused by extreme salt concentrations in the soil, has created a need to explore stress-responsive traits and decode their mechanisms. Metallothioneins (MTs) are low-molecular-weight cysteine-rich proteins that are known to play a role in decreasing oxidative damage during abiotic stress conditions. Our previous study identified date palm metallothionein 2A (PdMT2A) as a salt-responsive gene, which has been functionally characterized in yeast and Arabidopsis in this study. The recombinant PdMT2A protein produced in Escherichia coli showed high reactivity against the substrate 5′-dithiobis-2-nitrobenzoic acid (DTNB), implying that the protein has the property of scavenging reactive oxygen species (ROS). Heterologous overexpression of PdMT2A in yeast (Saccharomyces cerevisiae) conferred tolerance to drought, salinity and oxidative stresses. The PdMT2A gene was also overe...
Agriculture, 2019
The salinity tolerance mechanism in date palm through antioxidation has not been completely decip... more The salinity tolerance mechanism in date palm through antioxidation has not been completely deciphered to date. Therefore, this study aimed to investigate the role of various antioxidants in salinity tolerance. Two date palm cultivars, contrasting in salinity tolerance, were used as model plants in a comparative study designed to detect changes in growth, Na+ and K+ uptake, reactive oxygen species (ROS), and antioxidant accumulations, when plants were exposed to salt stress. The results showed that salinity treatment had a more substantial negative effect on the growth and photosynthetic pigmentation of the susceptible ‘Zabad’ cultivar than on the tolerant ‘Umsila’ cultivar, probably due to the ability of ‘Umsila’ to accumulate less Na+ and more K+, to maintain a normal concentration of ROS and to produce more non-enzymatic antioxidants, including glutathione, phenolic compounds, flavonoids, and proline. Under salinity, ‘Umsila’ could also activate more superoxide dismutase (SOD), c...
Forests, 2017
Date palm (Phoenix dactylifera L.) is a major fruit tree in the Middle East and it is a plant con... more Date palm (Phoenix dactylifera L.) is a major fruit tree in the Middle East and it is a plant considered to be tolerant to a variety of abiotic stresses, including salinity. However, the physiological basis of its salinity tolerance is not fully known. The objective of this study was to screen Omani date palm cultivars for tolerance or susceptibility to salt stress. Seedlings from 10 commercially important date palm cultivars were subjected to 240 mM NaCl, and several physiological parameters related to salinity tolerance traits were evaluated upon treatment. The cultivars were divided into two groups based on the dry weight (DW) of their leaf and root tissues, a parameter which was used as an indication of healthy growth. The results revealed that photosynthesis, electrolyte leakage (EL), and the shoot K + /Na + ratio were all significantly reduced in the susceptible cultivars. In addition, the relative water content was higher in the tolerant cultivars in comparison with the susceptible ones. These results suggest that although date palm is tolerant to high salinity, there is variation in tolerance among different cultivars. Shoot Na + exclusion, photosynthesis, and membrane stability are apparently the main determinants of tolerance and can be used in salinity tolerance screening of date palm. The results have shown new very tolerant cultivars (Manoma and Umsila) that could serve as genetic resources for improved date palm tolerance to salinity.
International Journal of Agriculture and Biology, 2012
III International Date …, 2006
... 68(3):2629). MAF. 2004. Ministry of Agriculture and Fisheries. Agriculture Census. Mekki, MIA... more ... 68(3):2629). MAF. 2004. Ministry of Agriculture and Fisheries. Agriculture Census. Mekki, MIA, Hamouda, AMM and Al Abri, ASR 1998. Fruit Orchards Science. 1 st ed. 1997. The Royal Sultani Deewan.,Muscat, Oman. (Arabic Ed.). Montgomery, DG 2001. ...
International Journal of Agronomy
Salinity is a global agricultural problem, resulting in a significant reduction in the plantation... more Salinity is a global agricultural problem, resulting in a significant reduction in the plantation areas and the crop yields, especially in arid and semiarid regions. The date palm is relatively salt-tolerant plant species, although the nature of salt tolerance is poorly understood. In this study, the salt stress responses of a salt-tolerant “Umsila” was compared with salt-susceptible “Zabad” date palm cultivars. Various physiological parameters, plant-water relations, and anatomical characteristics were analyzed. The results revealed that although salinity has negatively affected both cultivars, Umsila exhibited more stable photosynthesis than Zabad as reflected by the quantum yield (Qy) and the stomatal conductance (GS). Similarly, Umsila showed a more dynamic root system and efficient water relations than Zabad as demonstrated by the leaf water potential (LWP) and relative water content (RWC) during salinity. Umsila also accumulated greater abundances of soluble sugars, potassium ...
International Journal of Molecular Sciences, 2019
Although the date palm tree is an extremophile with tolerance to drought and certain levels of sa... more Although the date palm tree is an extremophile with tolerance to drought and certain levels of salinity, the damage caused by extreme salt concentrations in the soil, has created a need to explore stress-responsive traits and decode their mechanisms. Metallothioneins (MTs) are low-molecular-weight cysteine-rich proteins that are known to play a role in decreasing oxidative damage during abiotic stress conditions. Our previous study identified date palm metallothionein 2A (PdMT2A) as a salt-responsive gene, which has been functionally characterized in yeast and Arabidopsis in this study. The recombinant PdMT2A protein produced in Escherichia coli showed high reactivity against the substrate 5-dithiobis-2-nitrobenzoic acid (DTNB), implying that the protein has the property of scavenging reactive oxygen species (ROS). Heterologous overexpression of PdMT2A in yeast (Saccharomyces cerevisiae) conferred tolerance to drought, salinity and oxidative stresses. The PdMT2A gene was also overexpressed in Arabidopsis, to assess its stress protective function in planta. Compared to the wild-type control, the transgenic plants accumulated less Na + and maintained a high K + /Na + ratio, which could be attributed to the regulatory role of the transgene on transporters such as HKT, as demonstrated by qPCR assay. In addition, transgenic lines exhibited higher chlorophyll content, higher superoxide dismutase (SOD) activity and improved scavenging ability for reactive oxygen species (ROS), coupled with a better survival rate during salt stress conditions. Similarly, the transgenic plants also displayed better drought and oxidative stress tolerance. Collectively, both in vitro and in planta studies revealed a role for PdMT2A in salt, drought, and oxidative stress tolerance.
AFRICAN JOURNAL OF AGRICULTURAL RESEEARCH, 2012
Africa that are characterized by high evapotranspiration, low and sporadic rainfall and dependenc... more Africa that are characterized by high evapotranspiration, low and sporadic rainfall and dependency on irrigation for crop cultivation. The effects of sub-optimal irrigation on the chemical properties of dates were investigated. Chemical quality attributes of date palm (cv. Khalas) grown in northern Oman showed variable responses to reduced frequency of irrigation water applied during fruit development. Trees irrigated on a daily basis showed a significantly higher fruit water content, juice volume, and titratable acidity (TA). Deficit irrigation treatments had the highest total-and reducing sugar content. Trees under water stress that were irrigated once per week showed significantly high dry matter, total soluble solids (TSS) and pectin. Sucrose, tannin and pH were not significantly different among irrigation treatments. Manipulation of irrigation frequency can be used to enhance certain chemical fruit quality attributes of dates.
Africa that are characterized by high evapotranspiration, low and sporadic rainfall and dependenc... more Africa that are characterized by high evapotranspiration, low and sporadic rainfall and dependency on irrigation for crop cultivation. The effects of sub-optimal irrigation on the chemical properties of dates were investigated. Chemical quality attributes of date palm (cv. Khalas) grown in northern Oman showed variable responses to reduced frequency of irrigation water applied during fruit development. Trees irrigated on a daily basis showed a significantly higher fruit water content, juice volume, and titratable acidity (TA). Deficit irrigation treatments had the highest total-and reducing sugar content. Trees under water stress that were irrigated once per week showed significantly high dry matter, total soluble solids (TSS) and pectin. Sucrose, tannin and pH were not significantly different among irrigation treatments. Manipulation of irrigation frequency can be used to enhance certain chemical fruit quality attributes of dates.
Int. J. Agric. Biol, 2010
2010. Effects of salinity stress on growth of lettuce (Lactuca sativa) under closed-recycle nutri... more 2010. Effects of salinity stress on growth of lettuce (Lactuca sativa) under closed-recycle nutrient film technique.
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Papers by Latifa AL-Kharusi