Effects of overexpression of ZmSUS1 gene on drought resistance of maize

Abstract

Due to climate changes such as water shortage and global warming, crops are increasingly affected by drought stress during their development in today's world, and drought has become one of the main natural factors that reduce crop production. Sucrose synthase (SUS), as a key enzyme for regulating sucrose decomposition, responds to drought stress by regulating sucrose catabolism and affecting soluble sugar content in plants. In this paper, the phylogenetic tree of SUS gene family was constructed to analyze the genetic relationship of SUS genes in different plant species, and the cis-acting elements in the promoter of maize ZmSUS1 gene were analyzed. In this study, ZmSUS1 gene was cloned from maize and transgenic maize plants expressing ZmSUS1 were successfully constructed by Agrobacterium transformation. Molecular identification of transgenic maize lines was carried out by BAR gene PCR and qRT-PCR of ZmSUS1 gene. Simulated drought experiments were carried out on the identified positive lines and CK lines of maize. It was found that compared with CK lines of maize, transgenic maize lines had higher expression of ZmSUS1 gene, better growth phenotype and stronger drought resistance. The relative water content, ABA and proline contents of transgenic maize lines also increased greatly. In addition, the soluble sugar content in transgenic corn is also higher than that in CK plants. As a result under drought stress, ZmSUS1 gene can maintain higher water content in plant leaves by regulating sugar metabolism and the steady state of soluble sugar in the body, thus significantly improving the drought resistance of maize. This study provides important insights and technical strategies for further analyzing the mechanism of maize ZmSUS1 gene responding to drought stress and improving maize drought resistance through molecular breeding technology.