Genetic modification of Gossypium arboreum universal stress protein (GUSP1) improves drought tolerance in transgenic cotton (Gossypium hirsutum).

Abstract

Cotton crop suffers shortage of irrigation water at reproductive stage which reduces the yield and fibre quality. Universal stress proteins belong to Pfam00582 which enables several plants to cope with multiple stresses via ATP binding. GUSP1 (Gossypium arboreum USP) is one of such proteins; its amino acids were mutated after in silico simulations including homology modeling and molecular docking analysis. Transgenic cotton plants were developed through Agrobacterium mediated genetic transformation by using mutated pmGP1 and non mutated pGP1 constructs under CaMV35S promoter. PCR and semi-quantitative PCR analyses confirmed the amplification and expression of transgene in transgenic plants. It was revealed that leaf relative water content, total chlorophyll content, CO2 assimilation as net photosynthesis, stomatal conductance, total soluble sugars and proline content was significantly increased at P\u2009≤\u20090.0001 and P\u2009≤\u20090.001 in both the pmGP1 and pGP1 transgenic plants as compared to non transgenic control plants. Moreover, relative membrane permeability and the transpiration rate were reduced significantly at P\u2009≤\u20090.0001 and P\u2009≤\u20090.001 respectively in transgenic plants under drought stress. Furthermore, the T1 transgenic seedlings containing pmGP1 mutated construct showed longer roots under desiccation stress imposed by 5% PEG. Transgene inheritance into the T1 progeny plants was confirmed by amplification through PCR and integration through Southern blot. Hence, our results pave the way to utilize the mutagenized known genes for increasing endurance of plants under drought stress. This will help to increase our understanding of drought tolerance/ sensitivity in cotton plants at the molecular level.\n\n\nSupplementary Information\nThe online version contains supplementary material available at 10.1007/s12298-021-01048-5.