Characterization of a chloroplast localized wheat membrane protein (TaRCI) and its role in heat, drought and salinity stress tolerance in Arabidopsis thaliana.

Drought and heat are the two major abiotic stresses that are detrimental to the yield and quality of crop plants such as wheat. In the present study, we cloned and characterize a membrane protein gene from wheat, previously identified through cDNA subtractive hybridization. BLAST analysis revealed that the newly identified gene belongs to Arabidopsis and rice RCI (Rare Cold Inducible) genes and hence named as TaRCI. In the present investigation, Arabidopsis transgenics were raised expressing TaRCI for functional analysis. The subcellular localization by translational fusion of TaRCI with GFP revealed the localization of GFP:TaRCI into the chloroplast. Arabidopsis transgenics expressing TaRCI performed better than the wild-type under simulated heat, drought and salinity stress conditions. Under heat stress conditions, TaRCI expressing transgenic seedlings showed faster recovery post heat stress and were healthy and greener than wild-type plants. Further, the TaRCI expressing plants accumulated more biomass in terms of size, rosette diameter and root length under simulated drought stress conditions also. Increased leaf size, and rosette diameter were also observed in the presence of ABA and SA. Transgenic plants also showed increase in physiological parameters such as maximum photosynthetic efficiency (Fv/Fm), proline and chlorophyll contents. Our study thus provides insight into a new wheat gene that could be an important regulator involved in multiple abiotic stresses and could be a potential candidate gene manipulation for improving stress tolerance in crop plants in general and wheat in particular.