Manavalan Lakshmi P, Prince Silvas J, Musket Theresa A, Chaky Julian, Deshmukh Rupesh, Vuong Tri D, Song Li, Cregan Perry B, Nelson James C, Shannon J Grover, Specht James E, Nguyen Henry T
Division of Plant Sciences, University of Missouri, Columbia, Missouri, United States of America.
Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska, United States of America.
PLoS One. 2015 Mar 10;10(3):e0120490. doi: 10.1371/journal.pone.0120490. eCollection 2015.
Cultivated soybean (Glycine max L.) cv. Dunbar (PI 552538) and wild G. soja (PI 326582A) exhibited significant differences in root architecture and root-related traits. In this study, phenotypic variability for root traits among 251 BC2F5 backcross inbred lines (BILs) developed from the cross Dunbar/PI 326582A were identified. The root systems of the parents and BILs were evaluated in controlled environmental conditions using a cone system at seedling stage. The G. max parent Dunbar contributed phenotypically favorable alleles at a major quantitative trait locus on chromosome 8 (Satt315-I locus) that governed root traits (tap root length and lateral root number) and shoot length. This QTL accounted for >10% of the phenotypic variation of both tap root and shoot length. This QTL region was found to control various shoot- and root-related traits across soybean genetic backgrounds. Within the confidence interval of this region, eleven transcription factors (TFs) were identified. Based on RNA sequencing and Affymetrix expression data, key TFs including MYB, AP2-EREBP and bZIP TFs were identified in this QTL interval with high expression in roots and nodules. The backcross inbred lines with different parental allelic combination showed different expression pattern for six transcription factors selected based on their expression pattern in root tissues. It appears that the marker interval Satt315-I locus on chromosome 8 contain an essential QTL contributing to early root and shoot growth in soybean.
栽培大豆（Glycine max L.）品种Dunbar（PI 552538）和野生大豆G. soja（PI 326582A）在根系结构和根系相关性状上表现出显著差异。在本研究中，鉴定了由Dunbar/PI 326582A杂交产生的251个BC2F5回交自交系（BILs）根系性状的表型变异。在幼苗期，使用锥形系统在可控环境条件下对亲本和BILs的根系进行了评估。栽培大豆亲本Dunbar在8号染色体上的一个主要数量性状位点（Satt315-I位点）贡献了表型上有利的等位基因，该位点控制根系性状（主根长度和侧根数量）以及地上部长度。这个QTL解释了主根和地上部长度超过10%的表型变异。发现该QTL区域在不同大豆遗传背景下控制各种地上部和根系相关性状。在该区域的置信区间内，鉴定出了11个转录因子（TFs）。基于RNA测序和Affymetrix表达数据，在这个QTL区间内鉴定出了关键的TFs，包括MYB、AP2-EREBP和bZIP TFs，它们在根和根瘤中高表达。具有不同亲本等位基因组合的回交自交系对于根据其在根组织中的表达模式选择的6个转录因子表现出不同的表达模式。看来8号染色体上的标记区间Satt315-I位点包含一个对大豆早期根系和地上部生长起重要作用的QTL。
