《植物生理学报》 2013, 49(12): 1433-1441

高粱肉桂酸羟化酶基因SbC4H1降低拟南芥的木质素合成

闫丽^1,2, 夏光敏¹, 黄应华^3,*, 赵双宜^1,*

¹山东大学生命科学学院, 植物细胞工程与种质创新教育部重点实验室, 济南250100; ²临沂大学生命科学学院, 山东临沂276000; ³USDA-ARS Plant Science Research Laboratory, Stillwater, OK 74075, USA

通信作者：黄应华；E-mail: syzhao@sdu.edu.cn, yinghua.huang@ars. usda.gov；Tel: 0531-88364525, 405-624-4142

摘　要：

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。

关键词：高粱; 肉桂酸4-羟化酶; 木质素合成; 生物能源

收稿：2013-10-08   修定：2013-11-21

资助：国家自然科学基金(31201273和31370331)和山东省博士基金(BS2010SW004)

Cinnamic Acid 4-Hydroxylase of Sorghum [Sorghum bicolor (L.) Moench] Gene SbC4H1 Restricts Lignin Synthesis in Arabidopsis

YAN Li^1,2, XIA Guang-Min¹, HUANG Ying-Hua^3,*, ZHAO Shuang-Yi^1,*

¹The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong University, Jinan 250100, China; ²College of Life Sciences, Linyi University, Linyi, Shandong 276000, China; ³USDA-ARS Plant Science Research Laboratory, Stillwater, OK 74075, USA

Corresponding author: HUANG Ying-Hua; E-mail: syzhao@sdu.edu.cn, yinghua.huang@ars. usda.gov; Tel: 0531-88364525, 405-624-4142

Abstract:

Cinnamic acid 4-hydroxylase (C4H) is the first hydroxylase enzyme of phenylpropanoid pathway, and its content and activity affects the lignin synthesis. In this study, we isolated a C4H gene SbC4H1 from the suppression subtractive hybridization library of brown midrib (bmr) mutants of Sorghum bicolor. Semiquantitative RT-PCR (sqRT-PCR) analysis showed thatSbC4H1 was up-regulated in most of bmr mutants. The transient expression assay in Arabidopsis protoplast indicated SbC4H1 was mainly located in the cytoplasm. Ectopic overexpression of SbC4H1 significantly lowered the content of lignin in Arabidopsis. sqRT-PCR indicated that several genes in phenylpropanoid pathway such as 4CL1, F5H1 and HCT were down-regulated in Arabidopsis. These results showed that, SbC4H1 played an inhibitory effect on the synthesis of lignin.

Key words: sorghum (Sorghum bicolor); cinnamic acid 4-hydroxylase; lignin synthesis; bioenergy