NO参与水分胁迫下ABA维持玉米初生根生长

Maize ( Zea mays L.cv. Nongda 108; from Nanjing Agricultural University, China ) was used in this experiment and 25% PEG was used to simulate low water potentials ( -1.6MPa ). At low water potentials, seedlings were pretreated with ABA inhibitors fluridone( FLU )( 10μM ) and tungstate ( Tun )( 1 mM ), both of them largely inhibited the primary root elongation, the addition of 100 μM ABA almost fully prevented the inhibition of root elongation. Low water potentials can induced a little amount of NO accumulated in the primary root of maize. Pretreatent with ABA inhibitors FLU substantially reduced the NO accumulation. The application of 100 μM ABA substantially increased the accumulation of NO in the primary root of maize plants pretreated with ABA inhibitors then exposed to low water potentials. Using the scavengers of NO pretreated and then explored the seedlings to low water potentials, the primary root elongation was largely inhibited. Under normal water potentials, low concentration NO donor sodium nitroprusside (SNP) substantially promoted the root elongation, but high concentration SNP substantially inhibited the root elongation. In summary, these results show that NO was involved in ABA maintained maize primary root growth at low water potentials, and ABA induced NO accumulation during low water potentials.