Abstract: Two putative natrate reducases coding genes AKl02363(OsNRl)and AKl02178(OsNR2)in rice were cloned and further qRT.PCR assays were performed to profile their expression responding to various environmental stimuli.0ur results showed that both of genes OsNRl and OsNR2 were down regulated by the treatments of NaCl and 15%PEG which we used to mimic the salt and drought stresses and were down regulated significantly responding to 10w temperature.Both of two genes were able to be induced by SNP which was used as a NO releaser.They displayed an asymmetric expression in shoot base of rice after gravistimulation.The expression of OsNRl and OsNR2 were up regulated in the lower half of rice shoot base, at 6 hours after gravistimulation more than six—fold increase in expression of OsNRl and OsNR2 were observed in the lower half shoot base compared to the upper half shoot base.Our data provided here showed that the two genes related to the generation of NO in vivo were dynamically regulated by environment factors including abio.stresses and gravistimulation suggested an essential role of NO to enhance plant fitness to withstand a variety of environmental constraints like salt, drought, cold and gravity.

Key words: Nitric oxide, Stress, Gravity, Relative expression

CLC Number: 

• S511