Overexpression of maize ZmbHLH167 positively regulates starch synthesis in maize
The aim of this study was to clone ZmbHLH167,a gene related to the regulation of starch synthesis from maize,and analyze its molecular characteristics and investigate its biological function in regulating starch syn-thesis in maize kernels.The full-length sequence of ZmbHLH167 was cloned from maize KN5585,the tissue expres-sion,subcellular localization and yeast transcriptional activity of ZmbHLH167 were characterized,and the morphol-ogy and the composition of kernels in maize overexpressing ZmbHLH167 gene for clarifying the functions of ZmbHLH167 in starch synthesis were analyzed.The expression levels of gene related to starch synthesis in kernels were analyzed by quantitative real-time PCR.As results,quantitative PCR assay revealed that ZmbHLH167 gene was highly expressed in the endosperm and leaves;subcellular localization results showed that ZmbHLH167 was a nuclear localized protein;transcriptional activity assay showed that ZmbHLH167 did not possess transcriptional ac-tivation activity in yeast;yeast two-hybrid results indicated that ZmbHLH167 functioned as a homodimer.Analysis of agronomic traits and kernel composition showed that ZmbHLH167 positively regulated the length,width,and 100-kernel weight of the maize kernels,as well as the contents of various starches in the kernels,and negatively reg-ulated the changes of soluble and reducing sugars in the kernels.Real-time quantitative PCR results showed that the expression levels of ZmGBSSI ZmGBSSIIa,ZmGBSSIIb,ZmISAI,ZmISAII and ZmISAIII at 15 days after pollination in transgenic lines were higher than those of the wild type.These results indicated that ZmbHLH167 positively regu-lates the expression of starch synthesis-related genes in seeds.In conclusion,this study demonstrated that the tran-scription factor ZmbHLH167 has an important role in increasing the starch content of maize kernels.
国家科技期刊平台
NSTL
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