Authors: Sagarika Mishra Ratikanta Behura Jay Prakash Awasthi Mohitosh Dey Debeeprasad Sahoo Sudipta Shekhar Das Bhowmik Sanjib Kumar Panda Lingaraj Sahoo
Publish Date: 2014/07/30
Volume: 34, Issue: 3, Pages: 1345-1359
Abstract
Salinity is a major threat to sustainable agriculture worldwide Plant NHX exchangers play an important role in conferring salt tolerance under salinity stress In this study a vacuolar Na+/H+ antiporter gene VrNHX1 Genbank Accession No JN6562111 from mungbean Vigna radiata was introduced into cowpea Vigna unguiculata by the Agrobacterium tumefaciensmediated transformation method Polymerase chain reaction and Southern blot hybridization confirmed the stable integration of VrNHX1 into the cowpea genome Comparative expression analysis by semiquantitative RTPCR revealed higher expression of VrNHX1 in transgenic cowpea plants than wildtype Under salt stress conditions T2 transgenic 35SVrNHX1 cowpea lines exhibited higher tolerance to 200 mM NaCl treatment than wildtype Furthermore T2 transgenic 35SVrNHX1 lines maintained a higher K+/Na+ ratio in the aerial parts under salt stress and accumulated higher Na+ in roots than wildtype Physiological analysis revealed lower levels of lipid peroxidation hydrogen peroxide and oxygen radical production but higher levels of relative water content and proline ascorbate and chlorophyll contents in T2 transgenic 35SVrNHX1 linesWe express our sincere thanks to Prof Sampa Das Bose Institute for providing the Agrobacterium tumefaciens strain EHA105 and the Center for Application of Molecular Biology to International Agriculture CAMBIA Australia for pCAMBIA2301 The research was supported by Grants from the Department of Biotechnology Government of India BT/PR10818/AGR/02/591/2008 and BT/01/NE/PS/08 SM is grateful to MHRD for Research Fellowship
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