谷子SiMYB76基因抑制种子油脂积累的功能分析

Functional Analysis of Inhibition of Seed Oil Accumulation by SiMYB76 Gene in Foxtail Millet

拟南芥AtMYB76转录因子参与调控脂肪族芥子油苷和油脂的积累过程。为深入了解谷子中的同源基因SiMYB76在种子油脂积累过程中的调控作用,从谷子品种‘豫谷1号’中克隆获得SiMYB76基因的全长编码域序列,对其进行烟草叶片的亚细胞定位研究,并初步分析其在种子油脂积累过程中的调控作用。结果表明,SiMYB76定位于烟草叶片细胞的细胞核中。在拟南芥myb76-2突变体背景下,异源表达SiMYB76基因不仅能够完全恢复突变体高含油量的表型,而且可显著调控油脂合成途径上多个关键基因的表达。由此可知,谷子SiMYB76通过调控油脂合成途径上关键基因的表达而显著抑制种子油脂积累,并在种子油脂积累过程中与拟南芥AtMYB76具有相似的生物学功能。

AtMYB76 transcription factor is involved in regulating the accumulation of aliphatic glucosinolates and oil in Arabidopsis thaliana.In order to further understand the role of the foxtail millet homologous gene SiMYB76 in the regulation of seed oil accumulation,we cloned the full length coding domain sequence of SiMYB76 gene from the S.italica cultivar‘Yugu1’to investigate its subcellular localization in tobacco leaf cells,and we also preliminarily analyzed its regulatory role in seed oil accumulation in A.thaliana.The results showed that SiMYB76 was located in the nucleus of tobacco leaf cells.Under the background of A.thaliana myb76-2 mutant,the hetero expression of SiMYB76 gene not only completely restored the higher oil content phenotype of the mutant,but also significantly regulated the expression of several key genes in the oil biosynthetic pathway.Therefore,SiMYB76 significantly inhibits seed oil accumulation by regulating the expression of key genes in the oil biosynthetic pathway,and exhibits a similar biological function with AtMYB76 during seed oil accumulation.