| Maize originated from the American continent and has the highest total production in the world,which is mainly cultivated in Northeast China,North China and other regions,combined with the global trend of climate development,drought becomes one of the main factors hindering the improvement.Drought limits maize growth by affecting maize cell protoplasts.RING-type E3 ubiquitin ligases play important roles in various biological processes in plants,including tolerance to abiotic and biotic stresses,hormone signaling,growth,development,and so on.A family of ring type ubiquitin ligases has been identified in plants such as Arabidopsis,rape,Brassica oleracea,soybean,apple,tomato,and wheat,but studies in maize have not been reported.This study utilized the reported Arabidopsis RING domain to search for a total of590 ZmRINGs genes in six categories in the maize genome,including RING-HC,RING-H2,RING-C2,RING-v,RING-G,and RING-S/T.The analysis of conserved sequences among ml showed that the same amino acid sequences existed among different ZmRINGs outcomes,meanwhile the phylogenetic tree revealed that ZmRINGs could be divided into11 evolutionary branches.Gene duplication suggests that gene duplication events may be a major driving force for the expansion of the ring gene family in maize.In this study,590 ZmRINGs genes were combined with drought tolerance phenotypes of maize inbred line AM368 at the seedling stage,and the genetic variation of ZmRING-93 was found to be associated with drought tolerance at the seedling stage.Therefore,ZmRING-93 was analyzed for drought tolerance in this study.Found that the expression pattern of ZmRING-93 was consistent in different organ and temporal dimensions under nine abiotic stress treatments at the seedling stage of maize B73,which was up-regulated by multiple adversity stresses and hormone induction.Under drought stress,the gene expression of ZmRING-93 was relatively elevated in the reproductive growth stage of maize.Subcellular localization results showed that ZmRING-93 was localized in the nucleus versus the cytoplasm.The results of in vitro protein purification experiments showed that ZmRING-93 protein was consistent with the predicted results.The results of the drought experiment at the seedling stage of transgenic Arabidopsis showed that it had a higher survival rate than the wild type,and ZmRING-93 overexpression improved the drought tolerance of transgenic Arabidopsis;Meanwhile,the results of table drought further indicate that ZmRING-93 has stronger water retention ability.The MDA content of transgenic Arabidopsis under drought stress and 10%PEG treatment was measured,and the results showed that the MDA content in ZmRING-93 transgenic Arabidopsis was much lower than that of the wild type.These results indicate that ZmRING-93 reduced the MDA content in transgenic Arabidopsis and weakened the degree of membrane lipid peroxidation.At the same time,the determination of H2O2 content in transgenic Arabidopsis under drought stress also showed the same results.Finally,the yeast double hybrid results indicate that there are multiple candidate genes for interaction in ZmRING-93,with some genes involved in plant stress resistance processes.In summary,these findings provide a basis for further research on the role of proteins containing RING structures in maize,and the exploration of drought resistance in ZmRING-93 provides new ideas for improving drought resistance in maize. |
