Physiological and Mechanical Role of 14-3-3 Lambda in Arabidopsis thaliana during Drought Stress

Climate changes this century due to global warming compel a greater understanding of molecular mechanisms for plant resistance to drought conditions. Plants undergo changes in their anatomy, morphology, mechanical properties and also in their gene expression in response to environmental stress. Using reverse genetics, anatomy and molecular biology approaches, the role of a 14-3-3 protein isoform in the presence of simulated drought conditions in the model organism Arabidopsis thaliana was investigated. The14-3-3 proteins serve the function of signal transduction in eukaryotes and their role in several abiotic and biotic stress conditions have been previously reported. In this study we used 12 isoforms of 14-3-3 that are expressed and well characterized in A. thaliana to determine which isoform of 14-3-3 contributed to drought stress resistance. A phenotypic assay for drought was conducted by growing all the mutants of the isoforms in media with Abscisic acid (ABA). The 14-3-3 lambda (Lambda) mutants showed deficiency in lateral root growth. Further investigations revealed significant differences in ion leakage, absolute water content, water potential and tensile strength in mutants deficient in 14-3-3Lambda versus wild-type (Columbia-0). Leaf anatomy of the 14-3-3Lambda mutants demonstrated a greater cell density and less intracellular airspace compared to Col-0 in well-hydrated and drought conditions. Roots of the 14-3-3Lambda mutants exhibited collapsed epidermal, endodermal and cortical cells in both wet and dry conditions. We thus conclude that 14-3-3Lambda is involved in drought tolerance and contributes in the development of roots and leaves crucial for drought resistance.