中国农业科学 ›› 2016, Vol. 49 ›› Issue (22): 4267-4283.doi: 10.3864/j.issn.0578-1752.2016.22.002

所属专题: 品质支撑农作物产业与未来发展

• 作物遗传育种·种质资源·分子遗传学 • 上一篇    下一篇

稻米品质性状基因的克隆与功能研究进展

张昌泉,赵冬生,李钱峰,顾铭洪,刘巧泉   

  1. 扬州大学农学院植物功能基因组学教育部重点实验室/江苏省粮食作物现代产业技术协同创新中心,江苏扬州 225009
  • 收稿日期:2016-08-12 出版日期:2016-11-16 发布日期:2016-11-16
  • 通讯作者: 刘巧泉,Tel:0514-87979242;E-mail:qqliu@yzu.edu.cn
  • 作者简介:张昌泉,Tel:0514-87937537;E-mail:cqzhang@yzu.edu.cn
  • 基金资助:
    国家转基因生物新品种培育重大专项(2016ZX08009003-004、2014ZX08009-024B)、国家自然科学基金(31561143008、31401354)、教育部博士点基金(20133250120001)

Progresses in Research on Cloning and Functional Analysis of Key Genes Involving in Rice Grain Quality

ZHANG Chang-quan, ZHAO Dong-sheng, LI Qian-feng, GU Ming-hong, LIU Qiao-quan   

  1. Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University/ Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou 225009, Jiangsu
  • Received:2016-08-12 Online:2016-11-16 Published:2016-11-16

摘要: 水稻是中国重要的粮食作物之一,高产与优质一直是品种改良的主要目标。目前,中国稻米品质表现总体偏低,在一定程度上影响了其市场竞争力。稻米品质属综合性状,是指稻米或稻米相关产品满足消费者或生产加工需求的各种特性,主要涉及稻米的物理和化学特性,包括精米率、米粒形状、透明度、蒸煮时间、米饭质地与香味、冷饭质地以及营养成分等指标。通常用碾磨品质、外观品质、蒸煮与食味品质和营养品质4个方面来评价稻米品质。近10年来,在上述稻米品质性状相关基因的克隆与功能研究领域已取得了长足的进展。水稻粒形不仅是重要的产量性状也是碾磨和外观品质的重要决定因素,目前已克隆了多个粒形相关的QTL和基因。根据粒形相关基因的表型效应可将其分为3类,即伴随植株矮化的小粒控制基因(第一类,包括D1D2D11D61SMG1等)、粒形特异基因(第二类,如GS3GL3.1GW7GW2GW5GS5GS6TGW6GW8BG2GW6aGS2等)和小圆粒基因(第三类,即SRS),其中只有第二类基因具有较好的育种利用价值。垩白是决定稻米外观品质的首要性状,同时也会影响碾磨品质。目前尽管已经鉴定了大量QTL,但只有少数QTL被精细定位和克隆,如Chalk5cyPPDKG1F1OsRab5aFLOURYENDOSPERM2PDIL1-1SSG4等主要通过调控胚乳灌浆和储藏物积累而影响稻米外观表现。淀粉占精米胚乳干重的90%以上,其组成与结构是决定稻米外观和蒸煮与食味品质的最重要因素。淀粉的合成是由多基因参与的复杂调控网络,直接参与淀粉合成的淀粉合成酶类基因的功能已经比较清楚;此外,参与胚乳淀粉代谢的一些转录因子如Dull、OsEBP89、OsEBP5、OsRSR1和OsbZIP58等也已被陆续鉴定和克隆。蛋白质是稻米的第二大成分,目前已克隆了众多的贮藏蛋白编码基因,并且已鉴定克隆了多个与蛋白质转运调控有关的基因如OsSarOsRab5aOsAPP6RISBZ1RPBFOsVPS9AOsGPA3GEF2等。赖氨酸是稻米中的第一限制必须氨基酸,通过过量表达富含赖氨酸蛋白(如RLRH1和RLRH2)或调控游离赖氨酸代谢等途径,均可显著提高稻米中的赖氨酸含量。稻米香味主要由2-AP决定,目前,已克隆了BADH2OsP5CS等参与2-AP合成调控的基因。在与稻米贮藏有关的脂质代谢方面,已克隆了脂肪酸氧化酶基因LOX-1LOX-2LOX-3以及脂质转运基因OsLTP36。此外,在稻米维生素、花青素和矿物质等合成调控方面也已鉴定克隆了多个重要基因。综上,稻米各品质性状都是由多基因控制,并且各性状间彼此交叉,其遗传调控非常复杂。本文重点就近年来控制稻米粒形与垩白、蒸煮与食味品质、储藏蛋白、脂类、维生素与矿质元素等合成与调控相关基因的克隆、等位变异和功能研究进行了综述,并对重要品质相关基因的育种利用进行了展望,期望为水稻优质育种提供参考。

关键词: 稻米品质, 基因克隆, QTL, 等位变异, 功能分析

Abstract: Rice (Oryza sativa L.) is one of the most important cereal crops in worldwide and also a major stable food in China, thus it is very important to breed novel rice cultivars with high yield as well as good grain quality. Rice grain quality is a complex trait, and usually means rice or rice products meeting the demand of end-users. Therefore, the concept of rice grain quality covers multiple features revealed by the physical and chemical characteristics, including milled rice ratio, grain shape, appearance, cooking time, aroma and its retention after cooking, eating palatability, and nutrition. In general, rice grain quality includes as milling quality, apparent quality, eating and cooking quality (ECQ), and nutritional value. The grain shape is not only the factors associated with yield but also crucial aspects of grain quality. In the past decade, there were rapid and great achievements in the cloning and functional analyses of the genes involving in rice grain qualities. For grain size and shape, numerous QTLs and genes have been cloned and characterized. These cloned genes could be divided into three groups based on the phenotypes of the mutants. The first group is associated with not only grain shape but also plant phenotype, such as D1, D2, D11, D61 and SMG1. The second group appears to specifically affect grain trait, including GS3, GL3.1, GW7, GW2, GW5, GS5, GS6, TGW6, GW8, BG2, GW6a and GS2, which are well valuable for improvement of grain yield and quality. The third group is called small and round seed, such as the SRS gene. Chalkiness is associated with both grain appearance and milling property, and only few such QTLs have been finely mapped and cloned, including Chalk5, cyPPDK, G1F1, OsRab5a, FLOURYENDOSPERM2, PDIL1-1 and SSG4. The starch comprises about 90% of the dry matter of rice endosperm, and thus the grain quality is greatly affected by starch composition and structure. Therefore, the starch biosynthesis plays a crucial role in the formation of rice quality, especially the eating and cooking quality. Recent studies had made deep understanding of the regulation network of starch biosynthesis related enzymes, and several transcriptional regulators had also been proven for involving in starch biosynthesis, such as Dull, OsEBP89, OsEBP5, OsRSR1 and OsbZIP58. For seed protein content, most of the genes for seed storage proteins have been well characterized, and some other genes, such as OsSar, OsRab5a, OsAPP6, RISBZ1, RPBF, OsVPS9A, OsGPA3 and GEF2 have also been identified associating with protein sorting and transporting. The aroma of cooked rice contributes to consumer sensory acceptance, and recent studies have confirmed that the BADH2 and OsP5CS genes are responsible for the synthesis of fragrance material 2-AP. As for the other nutritional factors, such as the contents of essential amino acid lysine, vitamins, anthocyanin and minerals, also many functional genes have been cloned or elucidated. Taken together, all of the above traits are known to be genetically controlled by multiple genes, and also interact with each other. In present review, the genetic networks involving in regulation of rice grain quality in the last decade were summarized and updated. It will give a better understanding of the genes that contribute to the overall grain quality as well as lay a foundation for development of new strategies for grain quality improvement with high yield in rice.

Key words: rice grain quality, gene cloning, quantitative trait locus (QTL), allelic variation, functional analysis