新功能、新界面、新体验,扫描即可下载生物谷APP!
首页 » 动植物学科 » Nature Genetics:中科院找到便宜又好吃大米的秘诀

Nature Genetics:中科院找到便宜又好吃大米的秘诀

来源:生物谷 2015-07-07 11:38


2015年7月7日讯 /生物谷BIOON/-- 中国培育专家们已经发现了用于创建水稻品种的秘密,可以提高数以百万计的亚洲人三餐。两队来自中科院的分子遗传学家们,独立工作并已经确定在不影响作物产率的情况下控制水稻形状和质地的基因。这两篇文章同时发表在最新的Nature Genetics

Susan McCouch是美国康奈尔大学水稻遗传学家,她评论这两篇研究时说道:“这个发现的影响是巨大的。水稻育种界一直有这么一个瓶颈— 我们已经能够提高水稻的产量或品质,但从来没能够同时提高这两者。”

在亚洲东南部,人们76%的热量摄取都来自大米。精明的大米购买者知道什么才是知道自己想要的——好大米是透明的,大米垩白(即不透明的点)表示不太好的口感。最好的大米是细长粒。Xiangdong Fu,北京中国科学院的遗传学家和其中一篇研究的资深作者解释说:“这种形状与米的质量有关。”

消费者对购买优良品质的大米在所不惜,所以一些国家的育种家们已经准备牺牲产量,只为培育高品质品种。印度人最爱的一种改良过的香米(Basmati),产量比改良前下降14%。不过,中国农民往往接受较低质量的品种,为了保持较高的产量。

这两篇研究都确认了一种与大米细长形状并且降低垩白关联的基因,对产量没有影响,可育成新的水稻品系。

这个基因名称为GL7或GW7,高度表达在两个美国水稻品种以及中国一个新品种称为TaifengA。该基因可以通过促进纵向细胞分裂超过横向细胞分裂,诱导大米形状变化。这个特定基因的拷贝数或等位基因越多,大米越细长。由于这个基因是显性的,这使得它可用于创建杂交品种。该基因的相邻基因能编码参与DNA转录的蛋白质,对形状改变有抑制的效果,不过这个抑制是可以被解除。

现在,“奇迹”基因已被确定,或许它可以被设计利用。“目前中国市场已经有部分大米品种包含这些等位基因,” Guosheng Xiong,中国农业科学院研究者和其中一篇研究的作者说,“现在我们了解这方面的知识,可以把这个基因引入给一些具有良好的口感和烹调的品质但并不看好的水稻品种。”

世界各地主食大致一样,但国家之间对大米大小,形状和味道的偏好差别很大。日本喜欢短,肥厚和有粘度的大米,这也解释了为什么他们的育种家已经在美洲引进的品种培育出GL7的第二个副本。不过几乎没有人喜欢垩白大米。垩白大米易碎,营养价值少,而且会让农民少挣很多。

无论这个基因将被培育到哪个品系中,都会提高中国散装大米的外观和口感。(生物谷Bioon.com)

本文系生物谷原创编译整理,欢迎转载!转载请注明来源并附原文链接。更多资讯就在生物谷资讯APP


DOI:10.1038/ng.3352
PMC

PMID

The OsSPL16-GW7 regulatory module determines grain shape and simultaneously improves rice yield and grain quality
Shaokui Wang,Shan Li,Qian Liu et al.

Abstract
The deployment of heterosis in the form of hybrid rice varieties has boosted grain yield, but grain quality improvement still remains a challenge. Here we show that a quantitative trait locus for rice grain quality, qGW7, reflects allelic variation of GW7, a gene encoding a TONNEAU1-recruiting motif protein with similarity to C-terminal motifs of the human centrosomal protein CAP350. Upregulation of GW7 expression was correlated with the production of more slender grains, as a result of increased cell division in the longitudinal direction and decreased cell division in the transverse direction. OsSPL16 (GW8), an SBP-domain transcription factor that regulates grain width, bound directly to the GW7 promoter and repressed its expression. The presence of a semidominant GW7TFA allele from tropical japonica rice was associated with higher grain quality without the yield penalty imposed by the Basmati gw8 allele. Manipulation of the OsSPL16-GW7 module thus represents a new strategy to simultaneously improve rice yield and grain quality.


DOI:10.1038/ng.3346
PMC

PMID

Copy number variation at the GL7 locus contributes to grain size diversity in rice
Yuexing Wang,Guosheng Xiong,Jiang Hu et al.

Abstact
Copy number variants (CNVs) are associated with changes in gene expression levels and contribute to various adaptive traits1, 2. Here we show that a CNV at the Grain Length on Chromosome 7 (GL7) locus contributes to grain size diversity in rice (Oryza sativa L.). GL7 encodes a protein homologous to Arabidopsis thaliana LONGIFOLIA proteins, which regulate longitudinal cell elongation. Tandem duplication of a 17.1-kb segment at the GL7 locus leads to upregulation of GL7 and downregulation of its nearby negative regulator, resulting in an increase in grain length and improvement of grain appearance quality. Sequence analysis indicates that allelic variants of GL7 and its negative regulator are associated with grain size diversity and that the CNV at the GL7 locus was selected for and used in breeding. Our work suggests that pyramiding beneficial alleles of GL7 and other yield- and quality-related genes may improve the breeding of elite rice varieties.

生物谷推荐英文原文报道:Geneticists reveal what makes great rice

温馨提示:87%用户都在生物谷APP上阅读,扫描立刻下载! 天天精彩!



相关标签

最新会议 培训班 期刊库