摘要
Beta-葡聚糖是由β-(1,3)和β-(1,4)糖苷键连接的非纤维素多糖,主要分布在谷类作物籽粒胚乳及糊粉层中,在高尔基体合成,经由囊泡运输到质膜,最终在细胞壁上沉积。通过增加胆汁酸排泄,延迟葡萄糖吸收,β-葡聚糖可有效降低胆固醇及血糖水平。Beta-葡聚糖合成酶基因家族成员最早在水稻(Oryza sativa)中得到鉴定,后在其他作物中陆续被发现。该基因家族包括3个主要成员:CslF、CslH和CslJ亚基因家族,起源于不同分支,经过趋同演化,执行合成β-葡聚糖的功能。Beta-葡聚糖基因家族成员均受到负选择压力,演化过程中序列高度保守。CslF亚家族基因成员相对较多,常在染色体上形成基因簇,CslF6是介导β-葡聚糖合成的主效基因。CslF亚家族在叶基部等幼嫩组织中表达水平相对较高,且明显受到光照强度的影响;CslH和CslJ亚家族成员较少,其中CslH亚家族在叶尖等成熟组织中的表达水平高,而CslJ亚家族在籽粒中有较高的表达水平。该文综述了β-葡聚糖合成酶基因家族成员的系统发育关系、表达模式,β-葡聚糖合成酶的亚细胞定位,以及作物中的定向育种研究进展,提出β-葡聚糖合成酶基因家族在染色体上的精准定位是未来的研究趋势,以期推动染色体工程在作物β-葡聚糖定向育种中的应用。
Beta-glucan is a noncellulosic polysaccharide linked byβ-(1,3)andβ-(1,4)glycosidic bonds,mainly distributed in the endosperm and aleurone layer of cereal crop grains with the synthesis in the Golgi apparatus,transportation to the plasma membrane by vesicles,and deposition in the cell wall.Beta-glucan is effective in reducing cholesterol and blood sugar levels by increasing bile acid excretion and delaying glucose absorption.Members of theβ-glucan synthase gene families were firstly identified in rice(Oryza sativa),and subsequently discovered in other cereal crops.There are three main subfamilies(CslF,CslH and CslJ)inβ-glucan synthase with the formation via convergent evolution.These three subfamilies originated from different clades and evolved their respective functions independently.During evolution,the purifying selection pressure resulted in the high conservation of sequences for members ofβ-glucan synthase gene families.CslF subfamily members are relatively large and often form gene clusters on chromosomes,and CslF6 is the key gene mediatingβ-glucan synthesis.CslF subfamily members showed the relatively high expression levels in young tissues such as leaf bases,and they were affected by light intensity obviously.There are relatively few members in CslH and CslJ subfamilies,CslH genes presented the relatively high expression levels in mature tissues such as leaf tips,while CslJ genes showed the relatively high expression levels in young one like grains.The research progress on the phylogenetic relationships for members ofβ-glucan synthase gene families,the subcellular localization ofβ-glucan synthase,and the directional breeding in cereal crops were summarized.The accurate localization ofβ-glucan synthase genes on chromosomes is prospected for the future research.The review aims to promote the directionally breeding of cereal crops with highβ-glucan content by the chromosome engineering.
作者
袁泓宇
崔冬丽
John Seymour Heslop HARRISON
刘青
YUAN Hongyu;CUI Dongli;John Seymour Heslop HARRISON;LIU Qing(Key Laboratory of Plant Resources Conservation and Sustainable Utilization,South China Botanical Garden,Chinese Academy of Sciences,Guangzhou 510650,China;South China National Botanical Garden,Guangzhou 510650,China;University of Chinese Academy of Sciences,Beijing 100049,China;Department of Genetics and Genome Biology,University of Leicester,Leicester,LE17RH,UK;Center for Conservation Biology,Core Botanical Gardens,Chinese Academy of Sciences,Guangzhou 510650,China)
出处
《热带亚热带植物学报》
CAS
CSCD
北大核心
2023年第2期295-304,共10页
Journal of Tropical and Subtropical Botany
基金
国家自然科学基金项目(32070359)
广东省自然科学基金面上项目(2021A1515012410)
科学技术部高端外国专家引进计划(G2021030013)
中国科学院华南植物园海外知名学者项目(No.Y861041001)资助。
