Preliminary Study On The Function Of Maize Yl Gene

Maize（Zea mays L.）is an important crop in our country and is widely used in food processing,feed production,and bio-energy manufacturing,and plays an important role in social and economic development.Mutant are important materials for studying plant growth and development,and exploring its mutation mechanism will help to analyze gene function and its involved network regulation.In this study,the candidate gene GRMZM2G095254（named as yl gene）,which was identified earlier in our laboratory and was related to recessive a yellow leaf（yellow leaf,yl）mutant and a dominant growth weak（Weaky）mutant,was studied.By analyzing the function of yl gene,the molecular mechanism of leaf color mutation and plant growth weakening was studied.The main results list follows:1.The yl mutant showed yellow leaf from the emergence of the seedling,and the plant died at the three-leaf stage.Exogenous sugar supplementation did not prolong the growth time of yl mutant.Observing the chloroplast structure found that the chloroplast structure of the yl mutant was imcomplete and could not form a complete photosynthetic system.The genotype verification of 136 materials of the self-breding progeny of the Weaky heterozygous mutant was carried out,and all were found to be heterozygous and wild type.It is speculated that the Weaky homozygous mutant may not grow normally,but this phenomenon occurs in more early on,it dies during seed formation or germination.Weaky heterozygous mutant showed stunted growth in the whole growth period compared with wild type,and the number of leaves and ear height were also significantly reduced and decreased compared with wild type.2.Bioinformatics analysis of the yl gene showed that the protein encoded by this gene has a total of 519 amino acids,and the molecule has typical AAA+related domains such as Walker A motif,Walker B motif,and ATP binding site that are unique to the AAA+ATPase family.The phylogenetic tree analysis of yl gene in Arabidopsis thaliana,rice and maize was constructed,and it was found that this gene has the closest evolutionary relationship with Os09g27340.1 in rice,and has a high homology.Subcellular localization showed that the fusion expression protein of yl gene and GFP was located at the endoplasmic reticulum3.The positive identification and phenotype observation of the yl gene overexpression and knockout lines showed that the leaves of the T₂ overexpression and knockout materials were green at the seedling stage.Expression analysis showed that the expression of the yl gene in the overexpressed material was up-regulated by 11.4 times compared with the wild type,which was lower than that in the yl mutant,so the phenotype was not obvious enough.4.Using YL as the bait protein,a positive interacting protein was screened in the yeast two-hybrid library of maize leaves,the protein is 153aa at the carboxy terminus of maize C₄-type PEPC.Yeast peer-to-peer validation and BiFC validation showed that maize C₄-type PEPC interact with YL.In addition,yeast point-to-point validation and BiFC validation showed that maize C₃-type PEPC and YL also interacted.The results of this experiment lay a foundation for elucidating the biological function of yl gene and explaining its role in maize chloroplast development,leaf development and photosynthesis.