Abstract:

To investigate the effects of exogenous NO donor sodium nitroprusside (SNP) on root growth and absorption in wheat seedlings (Triticum aestivum L.) under water stress, we cultured Yumai 49 seeds in Hoagland solution for 8 days, and then treated them for 2 days in Hoagland solution (CK) and Hoagland adding 50 μmol L^-1 SNP, 25% PEG-6000 ( Ó0.8 MPa), and 50 μmol L^-1 SNP+25% PEG-6000, respectively. The results showed that 50 mmol L^-1 SNP increased the length of primary roots and the number of lateral roots by 11.94% and 83.78% respectively, and enhanced the root activity by 55.88%. Meanwhile, the K⁺ content in wheat roots increased by 42.52%. In the patch-clamp experiment, SNP increased the inward-rectifying K⁺ current of wheat root cells under water stress and the NO specific scavenger c-PTIO reversed the effect above. The results above indicated that exogenous NO enhanced wheat drought resistance possible by improving wheat roots growth, increasing root activity to enhance K⁺ influx by activating root inward-rectifying K⁺ channels.

Key words:

Wheat (Triticum aestivum L.), Nitric oxide (NO), Water stress, Ion channel, Root system