Study On Mechanisms Of Histone H3K9 Methyltransferase Gene ZmSUV2 Regulating Seed Vigor Abstract

Seed vigor is an important index to measure the sowing quality of seeds.Therefore,revealing the mechanism of seed vigor difference has important theoretical significance and potential application value in guiding the production and processing of high vigor seeds and increasing crop yield.Previous studies found that seed vigor was the highest in the middle part of the ear and the lowest in the upper part of the ear,and histone H3K9 methylation played an important role in regulating seed vigor in different parts of the ear.The relationship between histone H3K9 methylation gene ZmSUVH2 and seed vigor was studied by subcellular localization,qRT-PCR and yeast two-hybrid.The main findings are as follows:1.The CDS sequence of maize ZmSUVH2 was cloned,and the expression vector of maize ZmSUVH2-YFP was constructed.The transient expression was induced into maize protoplast by PEG,indicating that the protein ZmSUVH2 was located in the nucleus.2.Expression pattern:qRT-PCR showed that ZmSUVH2 expression was the highest in leaves,followed by roots.In seeds,the expression of ZmSUVH2 was the lowest in dry seeds.The ZmSUVH2 expression in the middle seeds was always significantly lower than that of the upper seeds at different times of imbibition.3.Functional identification showed that low expression of ZmSUVH2 could improve seed vigor.4.The cDNA library was constructed from middle seeds of Z58 at different time of imbibition.Using pGBKT7-ZmSUVH2 bait vector to screen cDNA library,100 proteins were found to interact with ZmSUVH2.The GO and KEGG analysis showed that some proteins involved in protein degradation and amino acid synthesis interacted with ZmSUVH2.The five ZmSUVH2 interaction proteins were one-to-one verified,and the interaction was confirmed with three of them,namely Zm00001d002025(AP2-like ethylene-responsive transcription factor AIL5),Zm00001d032422(auxin-repressed 12.5 kDa protein)and Zm00001d031773(protein HVA22).