Enhancement of Drought Tolerance in Transgenic Arabidopsis thaliana Plants Overexpressing Chickpea Ca14-3-3 Gene

Plant 14-3-3 proteins are highly conserved, phospho-binding proteins, ubiquitous in nature that control major cellular functions. The genes encoding 14-3-3 family proteins are reported for involvement in plant stress tolerance. Therefore, we here studied the function of chickpea (Cicer arietinum L.) 14-3-3-like protein B with increased expression under drought stress in Arabidopsis thaliana. Compared to wild type, Ca-14-3-3-like protein B overexpressing lines showed a high rate of germination, more biomass, and increased root length at the seedling stage under osmotic stress caused by both polyethylene glycol (PEG-6000) and mannitol. In addition, chlorophyll content, proline content, relative water content (RWC), antioxidant enzyme activities, net photosynthesis, and water use efficiency were also higher in transgenic lines as compared to WT after drought stress. Staining with DAB and NBT indicated that transgenic lines accumulated less H2O2 than WT plants. Furthermore, Ca-14-3-3-like protein B overexpression also upregulated the transcript level of the certain stress-responsive genes (RD20, PDF1, and P5CS1) and of genes involved in lignin biosynthesis (PAL and CAD). Overall it can be concluded that Ca-14-3-3-like protein B improves the drought tolerance when overexpressed in Arabidopsis plants and the gene thus appears to be a promising candidate for crop improvement efforts.