ABSTRACT
In the present study, the effects of nitrate supply (low nitrogen: LN and high nitrogen: HN) on arsenate [As(V)] stress (25 M) responses in rice seedlings were monitored for 7 d. The LN+As treatment resulted in significant decline in As concentration (848 g g−1 DW) than that in As alone treatment (1434 g g−1 DW) in roots but no significant effect was seen in shoot. In contrast, HN +As treatment showed significant increase in shoot As (6.86 g g−1 DW) as compared to As alone treatment (3.43 g g−1 DW). The level of nitrate was increased in roots but declined in shoots in As alone treatment. Surprisingly, no improvement in nitrate level was seen in HN+As as compared to that in As treatment in both root and shoot. The expression analysis of transporters of As (Pht1;1, Lsi2 and NIP1;1) and nitrate (NRT2;1, NRT2;3a, NRT2;4) showed significant differences in expression patterns in As, LN+As and HN+As treatments.
