马铃薯StDREB4基因响应盐和干旱胁迫的功能研究OA

[Objective]Studying the relationship between the CBF/DREB1 family members and the salt tolerance and drought tolerance may provide scientific references for breeding new potato germplasms with excellent stress resistance.[Method]The expression patterns of potato CBF/DREB1 family members under salt and drought stresses were detected by RT-qPCR technology,and the key gene was screened.Potato transgenic lines with overexpression and knockdown expression were constructed to detect the function of the key gene in response to salt and drought stresses.Meanwhile,the action mechanism of the key gene was analyzed by detecting subcellular localization and screening the interaction proteins.[Result]Based on the RT-qPCR detection results,the StDREB4 gene was selected as the research object for functional analysis.The results of growth phenotype and physicochemical index detection showed that the overexpressing lines had more obvious phenotypic and index changes.Under salt stress,the overexpression of StDREB4 reduced the root length,fresh weight,root activity,photosynthetic capacity,antioxidant capacity and osmotic regulatory substance content of plants,as well as increased MDA content,thereby reducing the tolerance of potatoes to salt.However,under drought stress,the relevant indicators of plants overexpressing StDREB4 were superior to those of wild-type lines,which enhanced the tolerance of potatoes to drought.In addition,StDREB4 was located in the nucleus and had transcriptional activation activity.Three important interacting proteins,including EBF protein,DSK2A protein and PSMB3 protein,were screened out using yeast two hybrid technology.[Conclusion]The overexpression of StDREB4 may be involved in the ethylene signaling process through the ubiquitin degradation pathway,regulating multiple physicochemical index parameters,thereby reducing the tolerance of potatoes to salt and enhancing its tolerance to drought.