ABA Accumulation and PsAO Gene Expression in Field Pea under Water Deficit
نویسندگان
1 Faculty of Agriculture, University of Belgrade, Nemanjina 6, Zemun, Serbia.
2 Institute of Field and Vegetable Crops, Maksima Gorkog 30, Novi Sad, Serbia.
3 Institute of Field and Vegetable Crops, Maksima Gorkog 30, Novi Sad, Serbia.
4 Faculty of Agriculture, University of Belgrade, Nemanjina 6, Zemun, Serbia.
5 Institute of Field and Vegetable Crops, Maksima Gorkog 30, Novi Sad, Serbia.
6 Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, Belgrade, Serbia.
7 Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, Belgrade, Serbia.
doi
چکیده
The plant hormone Abscisic Acid (ABA) plays a crucial role in plant responses to drought and other abiotic stresses, facilitating adaptation mechanisms under water-deficit conditions. This study aimed to investigate the response of field pea (Pisum sativum) varieties to drought stress by evaluating ABA concentrations, stomatal conductance, and the expression of PsAO genes during the third leaf pair stage. Drought stress was simulated by withholding irrigation to impose moderate and severe levels of water deficit. A statistically significant increase in ABA concentration was observed in all tested pea varieties under stress conditions. Under moderate drought, stomatal responses varied among genotypes; however, severe drought triggered accelerated stomatal closure across all varieties. The cultivar Dukat exhibited the highest stomatal sensitivity, which corresponded with a tenfold increase in ABA concentration, suggesting a strong reliance on chemical (ABA-mediated) drought signalling. In contrast, Javor cultivar showed only a modest (2.5-fold) increase in ABA, despite reduced stomatal conductance, indicating a likely reliance on hydraulic signals for drought response. Gene expression analysis revealed that PsAO2 and PsAO3 genes were upregulated under drought, while PsAO1 expression remained relatively unchanged compared to the control plants. Notably, PsAO3 expression was consistently elevated under both moderate and severe drought, suggesting that this gene may play a central role in conferring drought tolerance in field pea. These findings highlight the importance of ABA biosynthesis and signalling, particularly via PsAO3, in the adaptation of pea plants to water-deficit conditions.
