Arsenate induced differential response in rice genotypes

• Arsenate (AS(V)) and its detoxification responses in studied two varieties of rice, PB1 and IR-64.
• PB1 variety showed higher accumulation of As(V) up regulation of gene transcripts.
• PB1 varieties were more capable of detoxifying As(V) through induction of antioxidant enzymes.
• Other stress related parameters were also more induced in PB1 variety.
• PB1 variety showed better protection against As(V) stress than IR-64.

To study the differential response in two rice genotypes (PB1 and IR-64), hydroponically grown 14 days old plants were exposed to 50, 150 and 300 µM As(V) for 24 and 96 h. Accumulation of As was not significantly higher in PB1 variety except at higher concentration (300 μM) and duration (96 h), but up regulation of gene transcripts were higher as compared to IR-64. Inhibition in seed germination, root–shoot length, chlorophyll and protein content was observed in both varieties with increasing concentration and exposure time. PB1 variety was found more capable to detoxify As(V) through induction of antioxidant defense system and other stress related parameters (cysteine, proline content). SDS-PAGE and semi quantitative RT-PCR analysis showed significant changes in protein profile and gene expression analysis. The results suggests that various studied parameters and transcripts accumulation showed a combinatorial type of tolerance mechanism in PB1 variety to provide better protection against As(V) stress.