Functional Analysis Of ZmMATE30 In Regulating The Resistance Of Maize Root To Aluminum Stress

Aluminum stress is a stress factor in acidic soil that seriously affects the growth and development of maize,which poses a serious threat to the yield,quality and food security of maize in China.The main part of aluminum stress is the root system,which can ca use the growth of the root system to be hindered or even necrosis,thereby affecting the absorption of nutrients and water by the root system,resulting in crop yield reduction or even death.Therefore,exploring the key genes of aluminum stress response and revealing their function and regulatory mechanism involved in aluminum stress response are of great significance for the creation of aluminum-tolerant maize germplasm and the selection of new varieties.Through preliminary research,the research group identified a dwarf mutant zmmate30 of maize EMS mutagenesis,which had a significantly shorter root system than the wild type,but significantly increased tolerance to aluminum stress.In this study,the resistance of mutant roots to aluminum stress,auxin response,expression pattern and promoter expression activity were further systematically analyzed to reveal the biological function of ZmMATE30 gene involved in aluminum stress response,and the main results obtained were as follows:1.Through the root phenotypic analysis of wild-type WT and mutant zmmate30 under hydroponic conditions,it was found that the plant height,leaf length and taproot length of maize zmmate30 mutant seedlings were significantly lower than WT.2.The exogenous NAA treatment of maize WT and zmmate30 showed that the relative root elongation of the mutant after exogenous NAA treatment was significantly higher than that of the wild type,and the root system of the mutant zmmate30 plant was insensitive to NAA treatment compared with the wild type.3.Through the aluminum stress treatment of maize WT and zmmate30,it was found that the relative elongation of the root system of the mutant zmmate30 was significantly higher than that of the wild type,and the further determination of aluminum content was consistent with the aluminum stress phenotype,indicating that the resistance of the mutant to aluminum stress was significantly increased.4.The results showed that the relative elongation of WT and zmmate30 was significantly higher than that of aluminum alone,and the inhibition effect of root length of both germplasms was significantly weakened by aluminum stress,indicating that NAA treatment had a mitigating effect on root growth inhibition under maize aluminum stress.5.The results of qRT-PCR showed that ZmMATE30 gene had higher expression in maize taproot PR,lateral root LR and seed root SR,and the gene could be significantly induced after NAA treatment alone and aluminum alone,and the expression pattern of ZmMATE30 gene was different in different types of roots of WT and mutants.6.The ZmMATE30 promoter was cloned and the transgenic Arabidopsis thaliana plants driving GUS expression were obtained,and the GUS activity analysis showed that the expression activity of stems,leaves and roots in transgenic plants was significantly enhanced under aluminum stress,indicating that aluminum stress could induce the expression of ZmMATE30 gene promoters in maize.