Agrotechnology

Co-expression of PgNHX1 and AtAVP1 improves tolerance to both water and salt stress in transgenic rice

2^nd International Conference on Agricultural & Horticultural Sciences

Radisson Blu Plaza Hotel, Hyderabad, India February 03-05, 2014

Sushma M Awaji, Prashantkumar, S Hanjagi, Rohini Sreevatsa and V R Sashidhar

Posters: Agrotechnol

Abstract:

Abiotic stresses such as drought and salinity are serious threats to modern agriculture. Climate change will likely make many places worse in terms of water availability and soil salinization which will have adverse impacts on food production in agriculture. Rice is the most preferred staple food for human population all over the world and it is frequently affected by several abiotic stresses including drought, salinity and cold. A number of transgenic improvements for abiotic stress tolerance have been achieved in rice. The present study reports that, the over expression of PgNHX1-AtAVP1 in rice improves drought and salt tolerance. When T 2 seeds were grown on media containing different concentrations of PEG (8000), -12 and -17 bars, the PgNHX1-AVP1 expressing rice plants showed enhanced root growth, which was hindered in the wild type seedlings. To screen putative T 2 plants for salt tolerance, stringent salt screening test was followed and root and shoot growth of T 2 putative transformants was used as a selection criterion. Some of the transgenics showed significantly higher root and shoot growth compared to wild type when they were subjected to 350 mM NaCl stress. To confirm the integration of the transgene in putative T 2 transgenic plants, PCR and RT-PCR analysis were performed. The results showed that all the selected seedlings were PCR positives and four lines were positive for RT-PCR analysis. Physiological studies viz., chlorophyll estimation, membrane stability index, cell viability test and K+/Na+ ratio were also conducted to assess their levels of stress tolerance in the T 2 generation. Some of the T 2 transformants showed lower percent reduction in chlorophyll content, higher membrane stability, cell viability and maintained higher K+/Na+ ratio after PEG and NaCl treatment compared to wild type. The results clearly demonstrated that transgenic rice plants over expressing PgNHX1-AVP1 had superior stress tolerance capacity as compared to non-transformed plants.

Biography :

Sushma M. Awaji has completed her post graduation at the age of 23 years from University of Agricultural Sciences, GKVK, Bangalore. At present she is pursuing Ph.D. degree with INSPIRE fellowship in the Department of Crop Physiology, UAS, GKVK, Bangalore, under the supervision of Dr. V. R. Sashidhar, with the thesis problem entitled A gene pyramiding approach to improve salt tolerance in Rice involving tonoplast and plasma membrane transporters. She has published 3 papers in international journals and presented 4 posters in international conferences.