| Soil salinity is a major threat to global food security.Salt stress is a major abiotic limiting factor for sustainable crop productivity.Plant salt tolerance is a complex feature that involves the synergy of many gene families that have multiple functions,such as controlling water loss through stomata,ion sequestration,metabolic regulation,osmotic regulation,and antioxidant defense.Although there are many reports on the antioxidant defense effects under salt stress,the relative importance of this process to the overall salt tolerance of plants is still a controversial issue.Plant responses to salt stress infiltration and ionic components are very complex,involving many genetic networks and metabolic processes.These responses depend primarily on the plant's inherent salt tolerance.Brassinosteroids(BRs)have been reported to have a positive effect on many processes during plant growth,development and various abiotic stress responses.In this experiment,"Jingrun No.35" Cucumber sativus L.was used as the material.Histochemical staining,plant physiology and biochemistry,transcriptome data analysis,and molecular biology experiments were used to study the exogenous24-epibrassinolide(EBL)under salt stress Cucumber sativus L.active oxygen,membrane damage,effects of osmolytes,chlorophyll content and chlorophyll fluorescence parameters,stomatal opening and anti-oxidase activity,EBL regulates Cucumber sativus L.salt tolerance at the transcription level,and qRT-PCT affects some Validation of difference table genes.It is helpful to understand the physiological effects and regulation mechanism of rapeseed under the stress of EBL,and to provide a theoretical basis for improving soil salinity damage to plant cultivation.The main results are as follows:1.Through the measurement of plant physiological indicators,compared with NaCl stress treatment alone,the content of ROS,MDA,and electrical conductivity in Cucumber sativus L.leaves decreased after the addition of exogenous brassinolide,and cell activity,proline The content,relative water content,chlorophyll content,stomatal conductance,chlorophyll fluorescence parameters,and antioxidant enzyme activities all increased to varying degrees.At the same time,the content of oxidized glutathione decreased,and the GSH/GSSG ratio increased.This shows that exogenous brassinolides can reduce the membrane damage,increase the antioxidant capacity andphotosynthetic capacity to enhance the salt tolerance of Cucumber sativus L.2.In this study,RNA sequencing was used to determine the molecular role of24-epibrassinolide(EBL)in salt stress.Of all the differentially expressed genes,1492 were differentially expressed genes(DEG)in EBL treatment(EBL + NaCl)compared to controls(NaCl only),including 875 up-regulated DEGs and 617 down-regulated DEGs.We selected 6 transcription factors from 875 up-regulated DEGs for qRT-PCR analysis to confirm RNA-Seq.Based on GO enrichment and KEGG pathway analysis,brassinolides are enhanced by regulating base metabolism,photosynthetic processes,plant circadian rhythms,response to stimuli and other biological processes and up-regulating some transcription factors,redox-related genes,and cytochrome p450-related genes.Salt tolerance of Cucumber sativus L.seedlings.3.qRT-PCR was performed on the six transcription factors WRKY19,WRKY54,MYB108,ERF4,ABCG3,and ABCI7.Compared with the control,the expression of MYB108,ERF4,ABCG3,and ABCI7 was higher after 6 hours of NaCl stress treatment.However,WRKY19 and WRKY54 were higher after NaCl treatment for 48 h,indicating that the expression of different transcription factors is different at different times under salt stress,but they are up-regulated compared to the control.Compared with NaCl stress alone,WRKY19,WRKY54,MYB108,ERF4,ABCG3,and ABCI7 were all up-regulated to varying degrees in EBL + NaCl treatment,indicating that exogenous brassinolide can regulate salt resistance of Cucumber sativus L.by up-regulating some transcription factors,Consistent with the results of transcriptome analysis. |
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