Study On The Mechanism Of Interaction Between Hydrogen Sulfide And Auxin In Alleviating Salt Stress In Arabidopsis Thaliana

The accumulation of a large amount of salt in the soil harms the growth of plants,affects the production performance of crops,reduces the crop production efficiency of farmers,and affects the yield of food.Salt stress can be carefully divided into initial osmotic stress and gradually increasing Na⁺,Cl^-stress,high concentration of sodium ion and chloride ion inhibit root growth by inhibiting cell division and elongation,which may affect the transport or synthesis of auxin in its roots.Auxin has been proved to play a key role in plant growth and development,especially in plant roots.When the content of auxin decreases,the growth and development of plants may be affected to a great extent.However,when plants suffer from adverse environment,plants will take corresponding measures,because plants themselves have the ability to resist the harm caused by various adverse environments,and they can protect themselves from stress by regulating a variety of biochemical mechanisms such as antioxidant biosynthesis,and the addition of exogenous signal molecules such as NO,CO can also help them resist the harm caused by stress,which is also reported in some articles.The addition of exogenous hydrogen sulfide(H₂S)can also improve plant growth under salt stress,and an appropriate amount of hydrogen sulfide can increase the content of auxin in plant roots.Arabidopsis thaliana was used as a model organism in this experiment.The effect of different concentrations of exogenous hydrogen sulfide on the root length of plant growth under high salt environment was discussed,and the effect mechanism of hydrogen sulfide on auxin in Arabidopsis seedlings under salt stress was explored.In order to find the mechanism of alleviating salt stress from the interaction between hydrogen sulfide and auxin.The main conclusions of this study are as follows:1.After adding different concentrations of Na HS to the normal 1/2MS solid medium,the root length of wild Arabidopsis thaliana seedlings became longer at first and then shorter,which showed that the root length of wild Arabidopsis thaliana seedlings was promoted at first and then inhibited,and the promoting effect was the best when 100?m Na HS was added,indicating that moderate concentration of hydrogen sulfide can promote the growth of plant roots.2.Under 100mM salt stress,the root length of wild Arabidopsis seedlings was significantly inhibited.When different concentrations of exogenous Na HS were given,the root length of Arabidopsis seedlings was alleviated by the addition of 50?m and 100?m Na HS,but what surprised us was that the root length was inhibited by the addition of 150?m and 200?m Na HS,which was similar to the above results.Through the analysis of MDA content of Arabidopsis thaliana seedlings in different treatment groups,it was found that the MDA content of normal growing seedlings was low,while that of seedlings under salt stress increased significantly,and with the addition of exogenous Na HS,the MDA content of plants decreased at first and then increased.Similarly,the MDA content was the lowest when 100?m Na HS was added,and the effect of alleviating salt stress was the best.In addition,the analysis of chlorophyll results of different treatment groups also showed that the addition of exogenous Na HS could improve the damage of salt to plant seedlings,and the mitigation effect was the best in 100?m Na HS.Finally,we analyzed the content of soluble sugar in the experimental group after different treatments,and the results were the same as the above.The content of soluble sugar was the lowest under 100?m Na HS.Finally,we determined that its hydrogen sulfide could improve the growth of plants in salt environment under 100?m Na HS.The follow-up experiments were carried out under 100?m Na HS.3.Compared with a series of PIN gene and AUX?DR5gene staining results of auxin in the roots of the control group and the experimental group growing in 100m M Na Cl,the staining degree of plant was the best and the relative fluorescence value was the highest when hydrogen sulfide was added to the normal medium,while the staining degree of 100?m Na HS in salt stress was relatively poor,and the relative fluorescence value was in the middle between the control group and the salt stress experimental group,lower than the control group,and higher than the experimental group growing in salt environment.The relative fluorescence value of plants growing under salt stress was the lowest.It shows that the addition of 100?m Na HS can improve the content of auxin in roots and alleviate the harm caused by salt stress;in addition,through the analysis of the relative expression of genes related to auxin transport and synthesis,hydrogen sulfide may alleviate plant root length mainly by affecting auxin transport,so as to improve plant tolerance under salt stress.