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肉桂酸羟化酶(C4H)是苯丙烷代谢通路的关键酶,其活性和含量直接影响木质素合成的效率。本文研究通过高粱bmr突变体的抑制差减杂交筛选、克隆到了一个C4H基因SbC4H1。半定量RT-PCR发现,SbC4H1在多个bmr突变体中上调表达。将SbC4H1-GFP融合基因转化拟南芥原生质体进行瞬时表达,发现SbC4H1表达产物蛋白定位于细胞质。SbC4H1在拟南芥中的异源表达明显降低其茎的木质素含量,并且下调了拟南芥4CL1、F5H和HCT等木质素合成基因的表达。这些结果表明,高粱SbC4H1抑制了拟南芥木质素的合成。
Cinnamic acid hydroxylase (C4H) is the key enzyme of phenylpropanoid metabolic pathway, its activity and content directly affect the efficiency of lignin synthesis. In this paper, a C4H gene SbC4H1 was cloned by suppression subtractive hybridization screening of sorghum bmr mutant. Semiquantitative RT-PCR revealed that SbC4H1 was upregulated in multiple bmr mutants. The SbC4H1-GFP fusion gene was transformed into Arabidopsis thaliana protoplast for transient expression and found that SbC4H1 expression product protein localized in the cytoplasm. Heterologous expression of SbC4H1 in Arabidopsis significantly reduced the lignin content of its stems and down-regulated the expression of lignin-synthesizing genes such as 4CL1, F5H and HCT in Arabidopsis thaliana. These results indicate that sorghum SbC4H1 inhibits Arabidopsis lignin synthesis.