大豆有两种生长习性:有限结荚,即主茎在开花后不再生长;无限结荚,即开花后继续生长。对于不同地区农民而言,两种习性的大豆都具有重要的经济价值。因此,帮助农民找到合适的大豆生长习性十分重要。
因此,普渡大学的Zhixi Tiana和其他科学家进行了一项研究,利用模式植物拟南芥鉴定决定大豆生长习性的基因。研究者将决定拟南芥主茎生长的基因与大豆整套遗传密码对比,将栽培大豆(G. max)的四个候选基因与其他大豆品种的基因对比,发现Dt1基因的一个单独核苷碱基对突变体是部分大豆植株有限生长的基础。(生物谷Bioon.com)
生物谷推荐原文出处:
PNAS doi: 10.1073/pnas.1000088107
Artificial selection for determinate growth habit in soybean
Zhixi Tiana,1, Xiaobo Wangb,1, Rian Leec, Yinghui Lib, James E. Spechtd, Randall L. Nelsone, Phillip E. McCleanc,2, Lijuan Qiub,2, and Jianxin Maa,2
aDepartment of Agronomy, Purdue University, West Lafayette, IN 47907;
bNational Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
cDepartment of Plant Sciences, and Genomics and Bioinformatics Program, North Dakota State University, Fargo, ND 58108;
dDepartment of Agronomy and Horticulture, University of Nebraska, Lincoln, NE 68583; and
eSoybean/Maize Germplasm, Pathology, and Genetics Research Unit, US Department of Agriculture–Agricultural Research Service, and Department of Crop Sciences, University of Illinois, Urbana, IL 61801
Determinacy is an agronomically important trait associated with the domestication in soybean (Glycine max). Most soybean cultivars are classifiable into indeterminate and determinate growth habit, whereas Glycine soja, the wild progenitor of soybean, is indeterminate. Indeterminate (Dt1/Dt1) and determinate (dt1/dt1) genotypes, when mated, produce progeny that segregate in a monogenic pattern. Here, we show evidence that Dt1 is a homolog (designated as GmTfl1) of Arabidopsis terminal flower 1 (TFL1), a regulatory gene encoding a signaling protein of shoot meristems. The transition from indeterminate to determinate phenotypes in soybean is associated with independent human selections of four distinct single-nucleotide substitutions in the GmTfl1 gene, each of which led to a single amino acid change. Genetic diversity of a minicore collection of Chinese soybean landraces assessed by simple sequence repeat (SSR) markers and allelic variation at the GmTfl1 locus suggest that human selection for determinacy took place at early stages of landrace radiation. The GmTfl1 allele introduced into a determinate-type (tfl1/tfl1) Arabidopsis mutants fully restored the wild-type (TFL1/TFL1) phenotype, but the Gmtfl1 allele in tfl1/tfl1 mutants did not result in apparent phenotypic change. These observations indicate that GmTfl1 complements the functions of TFL1 in Arabidopsis. However, the GmTfl1 homeolog, despite its more recent divergence from GmTfl1 than from Arabidopsis TFL1, appears to be sub- or neo-functionalized, as revealed by the differential expression of the two genes at multiple plant developmental stages and by allelic analysis at both loci.