Expression Characteristics And Functional Analysis Of CsWRKY46 Gene Involved In Salt Stress

Globally,melons are important crops that are widely cultivated,and they occupy an important position in production and consumption.However,the yield and quality of cucumber are seriously affected by abiotic stresses such as high salt in production,especially in facility cultivation,which in turn affects the agricultural economic benefits.Transcription factors play an important switching role in the process of plant stress resistance.The WRKY transcription factor family has always occupied an important position in the response of plants to stress.Therefore,the cucumber and overexpression transgenic Arabidopsis were taken as the research objects to clarify that what roles WRKY transcription factors are in salt stress.The role and molecular regulation mechanism in the stress environment can help to better understand the transduction and regulation of high-salt signals.In addition,the pretreatment of exogenous abscisic acid(ABA)on physiological and biochemical indicators and genes of cucumber seedlings under salt stress The regulation effects related to expression and fruit development were studied.Got the following result:1.Effects of salt stress on the expression of CsWRKY46 and cucumber seedlingsAfter salt stress treatment,CsWRKY46 was up-regulated in cucumber leaves and roots.ABA pretreatment could enhance the expression of CsWRKY46.CsWRKY46 responded to salt stress and exogenous ABA.After salt stress treatment,the accumulation of biomass of cucumber seedlings was significantly inhibited compared with the control,and the growth was slow;the leaf conductivity increased,and ABA pretreatment could alleviate the increase in conductivity under salt stress;salt stress caused the cells to lose water,relative When the water content decreases,exogenous ABA pretreatment can play a certain role in relief;after salt stress treatment,the antioxidant enzyme activity of cucumber seedlings first increased and then decreased,and the expression changes of antioxidant enzyme encoding genes in cucumber leaves were up-regulated and then down-regulated,almost all the expression changes in the roots are up-regulated;ABA pretreatment can increase the antioxidant enzyme activity of cucumber seedlings under salt stress;it can increase the expression of antioxidant enzyme genes to a certain extent.2.Expression changes of CsWRKY46 and fruit development genes in fruit stage of cucumberAfter the salt stress treatment,the CsWRKY46 gene was up-regulated with the expansion of the fruit.After ABA pretreatment,the salt stress reached the peak in advance.After salt treatment,almost all genes related to fruit cycle development are down-regulated in fruits.ABA pretreatment can increase the expression of these genes to a certain extent under salt stress.Under salt stress,the fruit cycle developmentrelated genes are highly expressed in the peel,proving that these genes play a role in cell division.3.Functional analysis of CsWRKY46 under salt stressAfter salt stress treatment,CsWRKY46 overexpressed transgenic Arabidopsis has a lower germination rate compared to wild type;compared to wild type,transgenic Arabidopsis overexpression conductivity increased high,proline content also increased significantly,antioxidant enzymes POD and GR activities were significantly enhanced;transgenic overexpression of Arabidopsis increased the expression of ABF4,ABI5 and other ABA pathway related genes and downstream functional genes;indicating that CsWRKY46 overexpression transgenic Arabidopsis during the germination process is not salt-tolerant,salt resistance is enhanced during growth.