Papers by Anna Panozzo
Agronomy
Common wheat grains are characterised by low concentrations of Ca, K, and Mg, which can be partia... more Common wheat grains are characterised by low concentrations of Ca, K, and Mg, which can be partially removed with the bran during milling processes. This preliminary study investigated the effects of foliar fertilisation at the earing stage with nitrates of Ca, Mg, and K contemporarily, together with a small amount of urea and protein hydrolysate as potential carriers, in two contrasting common wheat varieties, i.e., Solehio (medium proteins content) and Vivendo (high proteins content). Based on the preliminary grain-to-straw concentration ratio of these minerals, two biofortification targets were applied in order to increase their grain contents by +20% and +40%, in comparison with untreated controls. Here, we demonstrate that the highest fertilisation dose was effective in increasing grain K by 13% and Mg by 16% in Vivendo, and Ca by 7% in Solehio, with no boosting effects of the co-formulants urea and protein hydrolysate. In addition to some qualitative benefits due to nitrates s...
Agronomy, 2021
Root characteristics and metal uptake in the maize hybrid Naudi were studied in a pot trial, usin... more Root characteristics and metal uptake in the maize hybrid Naudi were studied in a pot trial, using soil artificially highly polluted with Zn, Cu, Co, Cd, and Pb. The addition of these metals as sulfates decreased the soil pH and increased electrical conductivity. As a result of increased bioavailability in the soil pore water, significantly higher concentrations of metals, particularly Pb, Cu, and Co, were found in the shoot tissues of maize at the 3-4 leaf stage. While the lowest increase was in Cd (0.89 mg kg −1 vs. 0.33 mg kg −1 for controls), Zn reached a critical threshold of 75 mg kg −1 vs. 2.76 mg kg −1. Fresh and dry weights of shoots and roots, as well as root length, were markedly reduced, whereas root diameter, tip density, and the branching index increased considerably. A significant adaptation strategy by maize in the polluted soil was an increased fraction of coarse root length and a decreased fraction of finer roots. We conclude that maize is very sensitive to multiple metal pollution, suggesting its potential use as a test plant to evaluate contaminated soils. As length was the most affected root characteristic, measurement of this parameter could be a way of screening genotypes for tolerance to metal contamination and possibly salinity. There also is future scope for investigating whether K fertilization might mitigate metal phytotoxicity, in view of the negative correlations between the shoot K concentration and concentrations of the supplied metals.
Frontiers in Plant Science, 2020
In order to reduce chemical fertilization and improve the sustainability of common wheat (Triticu... more In order to reduce chemical fertilization and improve the sustainability of common wheat (Triticum aestivum L.) cultivation, maintaining at the same time high production and quality standards, this study investigated the effects of three commercial biofertilizers on rhizosphere bacterial biomass, biodiversity and enzymatic activity, and on plant growth and grain yield in a field trial. The wheat seeds were inoculated with the following aiding microrganisms: (i) a bacterial consortium (Azospirillum spp. + Azoarcus spp. + Azorhizobium spp.); and two mycorrhizal fungal-bacterial consortia, viz. (ii) Rhizophagus irregularis + Azotobacter vinelandii, and (iii) R. irregularis + Bacillus megaterium + Frateuria aurantia, and comparisons were made with noninoculated controls. We demonstrate that all the biofertilizers significantly enhanced plant growth and nitrogen accumulation during stem elongation and heading, but this was translated into only small grain yield gains (+1%-4% vs controls). The total gluten content of the flour was not affected, but in general biofertilization significantly upregulated two high-quality protein subunits, i.e., the 81 kDa high-molecular-weight glutenin subunit and the 43.6 kDa low-molecular-weight glutenin subunit. These effects were associated with increases in the rhizosphere microbial biomass and the activity of enzymes such as b-glucosidase, a-mannosidase, b-mannosidase, and xylosidase, which are involved in organic matter decomposition, particularly when Rhizophagus irregularis was included as inoculant. No changes in microbial biodiversity were observed. Our results suggest that seed-applied biofertilizers may be effectively exploited in sustainable wheat cultivation without altering the biodiversity of the resident microbiome, but attention should be paid to the composition of the microbial consortia in order to maximize their benefits in crop cultivation.
Wood biochar produces different rates of root growth and transpiration in two maize hybrids (Zea mays L.) under drought stress, 2018
This study investigated the effects of wood-derived biochar (BC) applied at
1% to a C-poor silty-... more This study investigated the effects of wood-derived biochar (BC) applied at
1% to a C-poor silty-loam soil in the drought-tolerant (D24) and in the
drought-sensitive (P1921) Pioneer Hi-Bred maize hybrids in pot and field
trials (NE Italy). D24 had better growth than P1921 under rain-fed conditions
without irrigation and soil amendment. The addition of biochar increased
root growth in D24 (+38% root area) and decreases it in P1921 (−9%) at the
silking stage, while the fraction of finer roots (<250 μm diam.) was reduced
in D24 and increased in P1921. This led both hybrids to maintain the
maximum transpiration at a lower fraction of transpirable soil water (from
82% to 45% in D24, and from 46% to 22% in P1921). There were no
significant variations in plant nutrient contents, productivity and in the
protein and starch contents of the grains, whereas the lipid content was
reduced by biochar, particularly in P1921 (2.6% vs. 3% DW, −13%).
We conclude that biochar can be profitably used to enhance drought
tolerance in maize, possibly due to improvements in the physicochemical
characteristics and the water content of treated soils, although
maximum benefits are expected in drought-tolerant hybrids through
increased root elongation and transpiration.
Morphological and biochemical changes in maize under drought and salinity stresses in a semi-arid environment
Morphological and biochemical changes in maize under drought and salinity stresses in a semi-arid environment, 2019
This study investigated some morphological and biochemical responses of maize to drought and sali... more This study investigated some morphological and biochemical responses of maize to drought and salinity
in open field in Tunisia with the aim of gaining insights into tolerance mechanisms. After seedling
emergence, five treatments were applied until maturity: optimal water supply (control, 100% of maximum
evapotranspiration - ETM); irrigation at 70% ETM (moderate drought) and at 35% ETM (severe
drought); optimal supply of water containing 3 g NaCl L1 (moderate salinity) and 6 g NaCl L1 (severe
salinity). Here, we demonstrated that extreme drought and salinity severely decreased the leaf area
(74% and 55%, respectively) and the above-ground biomass (35% and 31%, respectively) at
silking stage, indicating that the photosynthetic leaf apparatus is highly sensitive and that drought has
a greater effect than salinity. Grain yield losses were also exacerbated under extreme stress conditions,
viz. severe drought (85% versus controls) and severe salinity (73%), while productivity under moderate
salinity approximated that of moderate drought, possibly due to increases in leaf chlorophyll
and carotenoid content and K/Na ratio. The leaf area and its relative water content were positively correlated
with grain yield under both salinity and drought stresses, and may therefore be used as
markers for effective screening of maize genotypes for better stress tolerance.
Frontiers in Plant Science, 2019
Waterlogging is a severe abiotic stressor causing significant growth impairment and
yield losses ... more Waterlogging is a severe abiotic stressor causing significant growth impairment and
yield losses in many crops. Maize is highly sensitive to the excess of water, and
against the background of climate change there is an urgent need for deeper
insights into the mechanisms of crop adaptation to waterlogging. In the present study,
changes in maize morphology at the 4–5 leaf stage and the expression of three
candidate genes for flooding tolerance in plants subjected to six continuous days of
waterlogging were recorded in 19 commercial hybrids and in the inbred line B73, with
the aim of investigating the current variability in cultivated hybrids and identifying useful
morphological and molecular markers for screening tolerant genotypes. Here it was
demonstrated that root parameters (length, area, biomass) were more impaired by
waterlogging than shoot parameters (shoot height and biomass). Culm height generally
increased in stressed plants (by up to C24% vs. controls), while shoot biomass was
significantly reduced in only two hybrids. Root biomass was reduced in all the hybrids, by
an average of 30%, and significantly in 7 hybrids, while root length and area were even
more severely reduced, by 30–55% vs. controls, depending on the hybrid. The earlier
appearance of aerial roots seemed to be associated with greater root injuries. In leaves,
the transcript of the PFP enzyme (phosphofructokinase), which is involved in glycolytic
reactions, was markedly up-regulated (up to double the values) in half the waterlogged
hybrids, but down-regulated in the others. The transcript of CYP81D8 (ROS-related
proteins) in waterlogged plants exhibited relevant increases or strong decreases in level,
depending on the hybrid. The transcript of the AOX1A gene, coding for a mitochondrial
respiratory electron transport chain-related protein, was markedly down-regulated in all
the treated hybrids. Expression analysis of these genes under extreme waterlogging only
partially correlate with the shoot and root growth impairments observed, and AOX1A
seems to be the most informative of them.
Sustainability, 2018
This study investigated the effects of a commercial biofertilizer containing the mycorrhizal fung... more This study investigated the effects of a commercial biofertilizer containing the mycorrhizal fungus Rhizophagus irregularis and the diazotrophic N-fixing bacterium Azotobacter vinelandii on root and shoot growth, yield, and nutrient uptake in common wheat (Triticum aestivum L.) in order to improve the sustainable cultivation of this widespread crop. The trials were carried out in controlled conditions (rhizoboxes) and in open fields over two years to investigate the interaction between inoculation and three doses of nitrogen fertilization (160, 120 and 80 kg ha −1) in a silty-loam soil of the Po Plain (NE Italy). In rhizoboxes, efficient root colonization by R. irregularis was observed at 50 days after sowing with seed inoculation, together with improved root tip density and branching (+~30% vs. controls), while the effects of post-emergence inoculation by soil and foliar spraying were not observable at plant sampling. In the open, field spraying at end tillering significantly increased the volumetric root length density (RLD, +22% vs. controls) and root area density (+18%) after about two months (flowering stage) in both years under medium and high N fertilization doses, but not at the lowest N dose. In absence of inoculation, RLD progressively decreased with increased N doses. Inoculation had a negligible effect on grain yield and N uptake, which followed a typical N dose-response model, while straw Zn, P, and K concentrations were seldom improved. It is concluded that medium-high N fertilization doses are required to achieve the target yield and standards of quality (protein contents) in wheat cultivation, while the use of this mixed VAM-PGPR biofertilizer appears to be a sustainable mean for minimizing the adverse effects of chemical N fertilizers on root expansion and for improving the uptake of low-mobility nutrients, which has potentially relevant environmental benefits.
Conference Presentations by Anna Panozzo
5th European Agroforestry Conference, 2021
Soybean cultivation in Italy has developed since the 80s mainly for animal feeding, thanks to its... more Soybean cultivation in Italy has developed since the 80s mainly for animal feeding, thanks to its high protein content, and for human uses mainly for oil production. Agroforestry practices are becoming increasingly important as a means to improve carbon sequestration and mitigate climate change. Soybean is a crop that could fit well with this new agricultural approach, especially because it is a nitrogen fixing species. Soybean is also increasingly used for nutraceutical production. Isoflavones are the most important nutraceutical compounds, and are used for their antioxidant activity and anticholesterolemic effect.
XLVIII Conference of Italian Society for Agronomy , 2019
XLVIII Conference of Italian Society for Agronomy , 2019
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Papers by Anna Panozzo
1% to a C-poor silty-loam soil in the drought-tolerant (D24) and in the
drought-sensitive (P1921) Pioneer Hi-Bred maize hybrids in pot and field
trials (NE Italy). D24 had better growth than P1921 under rain-fed conditions
without irrigation and soil amendment. The addition of biochar increased
root growth in D24 (+38% root area) and decreases it in P1921 (−9%) at the
silking stage, while the fraction of finer roots (<250 μm diam.) was reduced
in D24 and increased in P1921. This led both hybrids to maintain the
maximum transpiration at a lower fraction of transpirable soil water (from
82% to 45% in D24, and from 46% to 22% in P1921). There were no
significant variations in plant nutrient contents, productivity and in the
protein and starch contents of the grains, whereas the lipid content was
reduced by biochar, particularly in P1921 (2.6% vs. 3% DW, −13%).
We conclude that biochar can be profitably used to enhance drought
tolerance in maize, possibly due to improvements in the physicochemical
characteristics and the water content of treated soils, although
maximum benefits are expected in drought-tolerant hybrids through
increased root elongation and transpiration.
in open field in Tunisia with the aim of gaining insights into tolerance mechanisms. After seedling
emergence, five treatments were applied until maturity: optimal water supply (control, 100% of maximum
evapotranspiration - ETM); irrigation at 70% ETM (moderate drought) and at 35% ETM (severe
drought); optimal supply of water containing 3 g NaCl L1 (moderate salinity) and 6 g NaCl L1 (severe
salinity). Here, we demonstrated that extreme drought and salinity severely decreased the leaf area
(74% and 55%, respectively) and the above-ground biomass (35% and 31%, respectively) at
silking stage, indicating that the photosynthetic leaf apparatus is highly sensitive and that drought has
a greater effect than salinity. Grain yield losses were also exacerbated under extreme stress conditions,
viz. severe drought (85% versus controls) and severe salinity (73%), while productivity under moderate
salinity approximated that of moderate drought, possibly due to increases in leaf chlorophyll
and carotenoid content and K/Na ratio. The leaf area and its relative water content were positively correlated
with grain yield under both salinity and drought stresses, and may therefore be used as
markers for effective screening of maize genotypes for better stress tolerance.
yield losses in many crops. Maize is highly sensitive to the excess of water, and
against the background of climate change there is an urgent need for deeper
insights into the mechanisms of crop adaptation to waterlogging. In the present study,
changes in maize morphology at the 4–5 leaf stage and the expression of three
candidate genes for flooding tolerance in plants subjected to six continuous days of
waterlogging were recorded in 19 commercial hybrids and in the inbred line B73, with
the aim of investigating the current variability in cultivated hybrids and identifying useful
morphological and molecular markers for screening tolerant genotypes. Here it was
demonstrated that root parameters (length, area, biomass) were more impaired by
waterlogging than shoot parameters (shoot height and biomass). Culm height generally
increased in stressed plants (by up to C24% vs. controls), while shoot biomass was
significantly reduced in only two hybrids. Root biomass was reduced in all the hybrids, by
an average of 30%, and significantly in 7 hybrids, while root length and area were even
more severely reduced, by 30–55% vs. controls, depending on the hybrid. The earlier
appearance of aerial roots seemed to be associated with greater root injuries. In leaves,
the transcript of the PFP enzyme (phosphofructokinase), which is involved in glycolytic
reactions, was markedly up-regulated (up to double the values) in half the waterlogged
hybrids, but down-regulated in the others. The transcript of CYP81D8 (ROS-related
proteins) in waterlogged plants exhibited relevant increases or strong decreases in level,
depending on the hybrid. The transcript of the AOX1A gene, coding for a mitochondrial
respiratory electron transport chain-related protein, was markedly down-regulated in all
the treated hybrids. Expression analysis of these genes under extreme waterlogging only
partially correlate with the shoot and root growth impairments observed, and AOX1A
seems to be the most informative of them.
Conference Presentations by Anna Panozzo
1% to a C-poor silty-loam soil in the drought-tolerant (D24) and in the
drought-sensitive (P1921) Pioneer Hi-Bred maize hybrids in pot and field
trials (NE Italy). D24 had better growth than P1921 under rain-fed conditions
without irrigation and soil amendment. The addition of biochar increased
root growth in D24 (+38% root area) and decreases it in P1921 (−9%) at the
silking stage, while the fraction of finer roots (<250 μm diam.) was reduced
in D24 and increased in P1921. This led both hybrids to maintain the
maximum transpiration at a lower fraction of transpirable soil water (from
82% to 45% in D24, and from 46% to 22% in P1921). There were no
significant variations in plant nutrient contents, productivity and in the
protein and starch contents of the grains, whereas the lipid content was
reduced by biochar, particularly in P1921 (2.6% vs. 3% DW, −13%).
We conclude that biochar can be profitably used to enhance drought
tolerance in maize, possibly due to improvements in the physicochemical
characteristics and the water content of treated soils, although
maximum benefits are expected in drought-tolerant hybrids through
increased root elongation and transpiration.
in open field in Tunisia with the aim of gaining insights into tolerance mechanisms. After seedling
emergence, five treatments were applied until maturity: optimal water supply (control, 100% of maximum
evapotranspiration - ETM); irrigation at 70% ETM (moderate drought) and at 35% ETM (severe
drought); optimal supply of water containing 3 g NaCl L1 (moderate salinity) and 6 g NaCl L1 (severe
salinity). Here, we demonstrated that extreme drought and salinity severely decreased the leaf area
(74% and 55%, respectively) and the above-ground biomass (35% and 31%, respectively) at
silking stage, indicating that the photosynthetic leaf apparatus is highly sensitive and that drought has
a greater effect than salinity. Grain yield losses were also exacerbated under extreme stress conditions,
viz. severe drought (85% versus controls) and severe salinity (73%), while productivity under moderate
salinity approximated that of moderate drought, possibly due to increases in leaf chlorophyll
and carotenoid content and K/Na ratio. The leaf area and its relative water content were positively correlated
with grain yield under both salinity and drought stresses, and may therefore be used as
markers for effective screening of maize genotypes for better stress tolerance.
yield losses in many crops. Maize is highly sensitive to the excess of water, and
against the background of climate change there is an urgent need for deeper
insights into the mechanisms of crop adaptation to waterlogging. In the present study,
changes in maize morphology at the 4–5 leaf stage and the expression of three
candidate genes for flooding tolerance in plants subjected to six continuous days of
waterlogging were recorded in 19 commercial hybrids and in the inbred line B73, with
the aim of investigating the current variability in cultivated hybrids and identifying useful
morphological and molecular markers for screening tolerant genotypes. Here it was
demonstrated that root parameters (length, area, biomass) were more impaired by
waterlogging than shoot parameters (shoot height and biomass). Culm height generally
increased in stressed plants (by up to C24% vs. controls), while shoot biomass was
significantly reduced in only two hybrids. Root biomass was reduced in all the hybrids, by
an average of 30%, and significantly in 7 hybrids, while root length and area were even
more severely reduced, by 30–55% vs. controls, depending on the hybrid. The earlier
appearance of aerial roots seemed to be associated with greater root injuries. In leaves,
the transcript of the PFP enzyme (phosphofructokinase), which is involved in glycolytic
reactions, was markedly up-regulated (up to double the values) in half the waterlogged
hybrids, but down-regulated in the others. The transcript of CYP81D8 (ROS-related
proteins) in waterlogged plants exhibited relevant increases or strong decreases in level,
depending on the hybrid. The transcript of the AOX1A gene, coding for a mitochondrial
respiratory electron transport chain-related protein, was markedly down-regulated in all
the treated hybrids. Expression analysis of these genes under extreme waterlogging only
partially correlate with the shoot and root growth impairments observed, and AOX1A
seems to be the most informative of them.