Improved salt tolerance in rice (Oryza sativa L.) by co-expression of two vacuolar transporter genes involved in compartmentation and proton gradient generation

Abstract

Soil salinity is one of the world’s most serious environmental problem which reduces crop yield. Sequestration of excess cytosolic Na+ into vacuole is one of the most important successful strategies towards maintenance of ion homeostasis that averts the deleterious effects of Na+ in the cytosol by maintaining a higher ratio of K+/Na+. In the present study, transgenic rice plants (Var. Vikas) co-expressing PgNHX1 (Tonoplast Na+/H+ antiporter from Pennisetum glaucum) and AtAVP1(vacuolar H+-ppase from Arabidopsis thaliana) were developed along with single gene transgenics of PgNHX1 for comparing the performance of single and double transgenics by tissue culture-independent in planta transformation technique. Transgenic rice plants co-expressing PgNHX1 and AtAVP1 performed much better under high salt concentration of 300 mM NaCl with extensive root system. Physiological and molecular analysis proved that the co-expression of PgNHX1 and AtAVP1 enhanced salt tolerance to much higher level than single transgenics of PgNHX1 and wild type treated plants. DOI: https://doi.org/10.25174/2249-4065/2019/94888