Regulation Of Nitric Oxide On Lateral Root Development In Triticum Aestivum And Arabidopsis Thaliana

Lateral root as an important part of the root system maintains the normal life activities of plants by absorbing groundwater and mineral nutrients.As the second largest food crop in the world,wheat（Triticum aestivum L.）is seriously deficient in its yield of high temperature and saline-alkaline-stressed areas.Therefore,enhancing the tolerance of wheat to stress has become one of the focuses of researchers.Based on the importance of lateral roots in plant growth and development,it has become the key to explore the mechanism of lateral root development under stress conditions.Stress response in plants produces a large number of redox-active factors,and nitric oxide（NO）is an important component of these factors.The effect of NO on the development of lateral roots has been proposed before,however,the mechanism on the development of lateral roots is not yet clear.In this article,we selected Chinese Spring and Liaochun 10 wheat as research materials,and analyzed the root phenotype under NO₃^-（resource of NO production in plants）and NO treatment.The in-deep mechanism of NO mediated lateral root development was done by arabidopsis thaliana.Our results showed below:1.low concentrations of both NO₃^-and NO promoted the development of lateral roots,while high concentrations of NO₃^-and NO inhibited the development of lateral roots.At the same time,lateral root primordium also have the same tendency under NO₃^-and NO treatment.2.After the addition of NO scavenger c PTIO,the promotion effect of NO₃^-on the lateral roots of wheat was reduced and there was no significant changes on the lateral root primordium,indicating that the endogenous changes of NO produced by NO₃^-affected the process of lateral root primordium develop to be a lateral root.3.In arabidopsis,NO inhibited the lateral root emergence process by suppressing the accumulation of auxin in the lateral root primordium,and further results showed that the expression of auxin efflux transport PINs were reduced.While,PIN3,located at the apical of lateral root primordium and transport auxin out of lateral root primordium,presented differently responsing to NO among PIN proteins.NO up regulated PIN3 and further reducing the accumulation of auxin in the primordium leading to a slow development rate of lateral root primordium.4.Under salt and drought stress treatment,lateral root number was not significantly affected in pin3 mutant seeding.These results indicating that NO mediate PIN3 plays an important role in lateral root development.And it provides new ideas for the study of wheat stress tolerance.