《植物生理学报》 2018, 54(8): 1288-1304

拟南芥种皮粘液质形成及调控机制研究进展

鲁明闽^1,2, 徐艳¹, 王易平^1,2, 孔英珍³, 胡瑞波^1,*, 周功克^1,*

¹中国科学院青岛生物能源与过程研究所, 中国科学院生物燃料重点实验室, 青岛市生物质资源与环境工程研究中心, 山东青岛266101; ²中国科学院大学, 北京100049; ³中国农业科学院烟草研究所, 中国农业科学院烟草遗传改良与生物技术重点实验室, 山东青岛266101

通信作者：胡瑞波；E-mail: hurb@qibebt.ac.cn, zhougk@qibebt.ac.cn

摘　要：

植物细胞壁是地球上储量最丰富的可再生资源, 是人类生产和生活中能源、纤维、建筑材料和造纸等原料的主要来源。植物细胞壁的形成机制一直是近年来的研究热点, 研究植物细胞壁的形成机制不仅有助于更高效地将细胞壁转化为生物乙醇等可再生能源, 也将促进纤维生物质在食品、药品和纺织等领域的更高效利用, 对于新能源开发和人类生产生活均具有十分重要的意义。一些十字花科(如拟南芥, Arabidopsis thaliana)和车前科植物的种皮外层细胞在发育过程中会合成和分泌大量的粘液质多糖, 其在种子遇水后膨胀并释放, 形成透明胶状物质包裹种子周围。拟南芥种皮粘液质的主要成分为果胶质(主要为鼠李半乳糖醛酸聚糖I), 同时还含有少量的纤维素和半纤维素成分。种皮粘液质作为一种特化的细胞壁, 具有表型容易观察、分离提取简便、组成相对单一、缺失不影响植株生长发育等优点, 已成为研究植物细胞壁(果胶)多糖合成、调控及细胞壁组分间互作的理想模式体系, 近年来取得了较大的研究进展, 本文主要介绍拟南芥种皮粘液质的形成、组成及其调控机制方面的研究进展。

关键词：拟南芥; 细胞壁; 种皮粘液质; 果胶质

收稿：2018-02-02   修定：2018-04-20

资助：国家自然科学基金(31370328、31770336和31670302)。

Research progress on biosynthesis and regulation of seed coat mucilage in Arabidopsis thaliana

LU Ming-Min^1,2, XU Yan¹, WANG Yi-Ping^1,2, KONG Ying-Zhen³, HU Rui-Bo^1,*, ZHOU Gong-Ke^1,*

¹Key Laboratory of Biofuels, Qingdao Engineering Research Center of Biomass Resources and Environment, Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; ²University of Chinese Academy of Sciences, Beijing 100049, China; ³Key Laboratory of Tobacco Genetic Improvement and Biotechnology, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao, Shandong 266101, China

Corresponding author: HU Rui-Bo; E-mail: hurb@qibebt.ac.cn, zhougk@qibebt.ac.cn

Abstract:

Plant cell wall is the most abundant renewable resource on the earth. It serves as a major resource for energy, textile fiber, building materials and papermaking raw materials in various aspects of human living and industry. The mechanism of plant cell wall biosynthesis and regulation has been a hotspot in recent years. Elucidation of the mechanisms underlying plant cell wall formation will not only promote the efficient exploration of renewable energy resources (e.g. bioethanol), but also of great significance to the efficient utilization of lignocellulosic biomass in medicine, food and textile industry. Some of the cruciferous (e.g. Arabidopsis thaliana) and Plantaginaceae plant species synthesize a large amount of gel-like polysaccharides (mucilage) in the outer layer cells of seed coat during the seed development process. Upon imbibition in water, the mucilage expands, ruptures the outer seed coat and releases, forming a transparent gel-like capsule surrounding the seed surface. The main component of A. thaliana seed coat mucilage is pectin (mainly rhamnogalactoside I, RG I), but also contains a small amount of cellulose and hemicellulose components. As a specialized type of cell wall, seed coat mucilage has been considered as an excellent model system for the study of plant cell wall polysaccharide synthesis, regulation and interactions between different cell wall components. The research using seed coat mucilage has the following advantages: easy observation of the phenotype, simplified separation procedure, relatively homogeneous composition, no adverse effects on plant growth and development, etc. This review introduces the recent research progress on the formation and composition of A. thaliana seed coat mucilage, and its underlying molecular regulation mechanisms.

Key words: Arabidopsis thaliana; cell wall; seed coat mucilage; pectin