The NO-Mediated Redox Modifications Of Proteins In Maize Root In Response To Drought Stress

The drought stress often along with the oxidation(reactive oxygen species,ROS)stress and the increase of NO content.NO can close the stoma and inhibit ethylene(Eth)biosynthesis through scavenging ROS to strengthen plant drought resistance.In animals,NO mainly through the cGMP pathway and redox-based modification of target protein to exercise signal function.But in plants,separation the gene of adenosine acid cyclization enzyme are not completed,limiting the fuether research of cGMP pathway.More and more examples of regulation plant physiology activity by NO mediated protein modification has been reported,but how response to drought stress of NO in protein modification level are less known.In the present study,we use the maize as materials and use the physiology and molecular methods to explore how conduction and response drought signal in protein modification level by increase of NO content at drought conditions,that is the protein nitration modification and Snitrosylation modification to drought stress response,in order to reveals NO signal molecular mechanism in protein modification after translation level.The main research results are as follows:1.This experiment was conducted to drought stress and rewatering of maize seedling at different strength and different time.The results showed that drought stress can induce the increase of the content of ROS and NO in plants,so ROS and NO content have correlation with the stress intensity and duration.At the same time,the expression of the tyrosine nitration protein also have increased,although the nitration protein expressions show some flexibility when stress strength to a certain extent or stress reaches a certain time.These data showed that drought stress not only can induce oxidative stress,but also with nitration stress in the root system of maize.2.We pretreatment maize seedling with exogenous NO donor SNP and NO synthase inhibitors L-NAME under drought stress.The results showed that NO,ROS has played a very important physiological role when the plants in the drought stress.Pretreatment with exogenous NO donor can reduce the accumulation of ROS,and reduce the expression of carbonylation and nitrosylation protein,it can ease the proten carbonylation and nitration in maize roots at drought stress condition,but caused the protein nitrosylation at the same time,has obviously protect function of maize seedling in drought stress and improve the ability to resist drought.3.This study was cultivated the maize seedlings in drought stress by using different concentration of NO3-.The results showed that the ROS,protein nitrosylation produced in maize roots are relevant with the concentration of NO3-in nutrients,that is relevant with the endogenous NO formed in the roots under drought stress.The higher of endogenous NO content,the lower of the tyrosine nitration protein expression.Further shows that high concentrations of NO3-nutrients can provide NO3-to maize roots,and form the endogenous NO,so as to improve the ability of resist drought at drought stress condition.