Influence of Severe Drought on Leaf Response in ABA Contrasting Tomato Genotypes (Wild Type and flacca Mutant)

Abstract

The reaction of leaf growth to drought stress is controlled by various hormones, among which ABA is one of the most important. The aim of this study was to examine the effects of ABA deficiency on tomato leaf response under severe drought stress. Therefore, ABA-mutant (flacca) and wild type (Ailsa Craig) were selected for research and in the stage of second flower truss anthesis plants were exposed to severe water deficit. The effects of severe drought on wild-type leaves and flacca mutant showed that, as a result of reduced ABA concentrations, flacca plants were exposed to a higher degree of stress than wild-type leaves, which had a negative impact on the examined physiological and biochemical parameters. Severe drought caused stomatal closure, decreased water potential, specific leaf area, and chlorophyll concentrations in the leaves in both genotypes, but this was more pronounced in the mutant. Wild-type plants have accumulated more vitamin C and ABA and have a higher total antioxidant capacity in the leaves in dry conditions than flacca mutants, which contribute to their better adaptive response to stress. Based on this, it can be assumed that the ABA mutation has led to a decrease in the capacity for oxidative stress products caused by severe drought stress.

Differential Biotic and Abiotic Induced Stress Levels Confer Varying Morphological Responses in Okra (Abelmoschus esculentus L. Moench) Cultivars

“…A decline in leaf area results in decreased water loss due to low transpiration rates and this has been shown to be a drought avoidance strategy used by plants under drought stress 5 . Other authors have shown similar correlation between severe drought stress and a reduction in leaf area 52,53,59 . Plants generally show reduction in leaf area as a strategy to adapt to drought stress.…”

Differential Response of Two Tomato Genotypes, Wild Type cv. Ailsa Craig and Its ABA-Deficient Mutant flacca to Short-Termed Drought Cycles

“…A constitutively higher ascorbate content was also observed in the Ailsa Craig cv. tomato cultivar compared to the flacca mutant [88]. On the other hand, notabilis tomato mutants in comparison to WT possess a similar ascorbate level [89], as well as abi4-insensitive Arabidopsis mutant [90].…”

Assessing the Spatiotemporal Variability of Leaf Functional Traits and Their Drivers Across Multiple Amazon Evergreen Forest Sites: A Stochastic Parameterization Approach With Land‐Surface Modeling

“…Although the uncertainty ranges for the for V cmax25 regression coefficients also showed considerable overlap, the differences were greater than for the other two parameters, and the values appeared to follow climatic gradients, with higher PAR sensitivity (coefficient ) and slightly weaker auto-correlation (coefficient α) occurring at sites with greater PAR and rainfall (in increasing order of both PAR and rainfall: K67, K34, and Guy; Table 1). Varying sensitivity of traits in response to environmental change within one PFT has been reported in previous experimental studies (Anyia & Herzog, 2004;Martin-St Paul et al, 2012;Nielsen et al, 2019;Petrović et al, 2015;Ramírez et al, 2012;Yin et al, 2004). In fact, a study spanning a Mediterranean rainfall gradient found that Quercus ilex populations at the wettest site showed steeper declines in photosynthetic capacity (stomatal conductance and V cmax25 ) in response to soil water deficit than those populations at the drier sites (Martin-St Paul et al, 2012).…”