水稻脆性突变体叶的解剖结构和化学特性

作物学报ACTA AGRONOMICA SINICA 2008, 34(8): 1417−1423/zwxb/ ISSN 0496-3490; CODEN TSHPA9E-mail: xbzw@

DOI: 10.3724/SP.J.1006.2008.01417

水稻脆性突变体叶的解剖结构和化学特性

韦存虚1谢佩松1周卫东2陈义芳2严长杰3,*

(1扬州大学生物科学与技术学院; 2扬州大学测试中心; 3教育部植物功能基因组学重点实验室/江苏省作物遗传生理重点实验室, 江

苏扬州225009)

摘要: 植物机械强度是一个十分重要的农艺性状, 为了解作物控制机械强度的机制, 本文对一个水稻脆性突变体[bc7(t)]叶进行了细胞学观察及叶细胞化学组成分析。光镜和电镜观察都发现突变体厚壁细胞的细胞壁变薄; 对细胞

壁成分的化学分析显示突变体纤维素含量明显低于对照, 硅含量明显升高, 而木质素变化不明显; 木质素的组化反

应也显示了木质素在突变体和对照之间差异不大; X-射线微区分析表明, 硅元素在突变体叶表面明显提高。上述结果

表明, 突变体叶纤维素含量的降低影响了厚壁细胞次生壁的形成, 导致细胞壁变薄, 机械强度降低, 硅含量的升高

有助于突变体增强机械强度。

关键词:水稻; 脆性突变体; 叶; 纤维素; 硅

Anatomical Structure and Chemical Features of Leaf in Brittle Mutant of Rice

WEI Cun-Xu1, XIE Pei-Song1, ZHOU Wei-Dong2, CHEN Yi-Fang2, and YAN Chang-Jie3,*

(1 College of Bioscience and Biotechnology; 2 Analytical Centre; 3 Key Laboratory of Plant Functional Genomics, Ministry of Education / Jiangsu Key Laboratory for Crop Genetics and Physiology, Yangzhou University, Yangzhou 225009, Jiangsu, China)

Abstract: Plant mechanical strength is an important agronomic trait. A rice brittle mutant bc7(t) which derived from japonica variety Zhonghua 11 by radiation of 60Co-γ displayed normal phenotype similar to its wild type (WT) plants except for the fragi- lity of all plant body. To understand the mechanism of controlling plant mechanical strength, the anatomical structure and chemical features of leaf of brittle mutant bc7(t) were investigated. Anatomical analyses were carried out by means of various microscopic techniques, such as light microscopy, scanning electron microscopy and transmission electron microscopy. It was found that the cell walls of sclerenchyma cells of leaf sheath and leaf blade in the mutant were thinner than that in WT. For histochemical loca- lization of lignin, fresh freezing-cut transverse sections of leaf blade and sheath were stained with Wiesner reagents. Responding

to the Wiesner reaction, the sclerenchyma cells below the epidermis, vascular bundle sheath and xylem were stained red. Though no noticeable staining difference in leaf blade between WT and mutant, the sclerenchyma cells of leaf sheath of mutant were stained slightly deeper than that of WT. Separation and purification of cell wall of leaf blade and sheath were carried out. The lignin content of cell wall was determined by thioglycollic acid method, the results revealed a slightly higher lignin content in mutant than in WT without significant difference. The cellulose content of cell wall was assayed with the anthrone reagent; the results showed that the amount of cellulose of leaf blade and sheath in mutant was significantly lower than that in WT. The test of silicon content of cell wall showed an increased content in the mutant. The energy dispersive X-ray micro-analysis attached to the FE-SEM provided the information on the distribution and content of silicon in the epidermal cells of leaf blade and sheath. The

X-ray map analysis at the upper and lower epidermis of leaf blade and outer epidermis of leaf sheath showed that the content of silicon in mutant was obvious higher than that in WT. The result from silicon X-ray mapping of upper epidermis of leaf blade indicated that the distribution of silicon was concentrated in cell wall of silica cells. X-ray point analysis on the upper epidermis of leaf blade in the cell walls of silica cell, dork cell, long cell, and bulliform cell showed that the contents of silicon at these locations

in mutant were all higher than these in WT. These results suggested that the reduction of cellulose might affect the formation of

基金项目:国家自然科学基金项目(30300215, 30300220); 国家重点基础研究发展计划(973计划)项目(2005CB120804)

作者简介:韦存虚(1973–), 男, 安徽临泉人, 博士, 副教授, 从事植物细胞结构与功能研究。

*通讯作者(Corresponding author):严长杰。

Received(收稿日期): 2007-12-27; Accepted(接受日期): 2008-03-28.