Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America.
PLoS One. 2010 Nov 22;5(11):e14021. doi: 10.1371/journal.pone.0014021.
In this study, we established a comprehensive genetic map with a large number of progeny from a three-generation hybrid Populus intercross, and phenotyped the lignin content, S/G ratio and 28 cell wall subcomponents both in stems and roots for the mapping individuals. Phenotypic analysis revealed that lignin content and syringyl-to-guaiacyl (S/G) ratio using pyrolysis molecular beam mass spectroscopy (pyMBMS) varied among mapping individuals. Phenotypic analysis revealed that stem lignin content is significantly higher than that in root and the quantified traits can be classified into four distinct groups, with strong correlations observed among components within organs. Altogether, 179 coordinating QTLs were detected, and they were co-localized into 49 genetic loci, 27 of which appear to be pleiotropic. Many of the detected genetic loci were detected differentially in stem and root. This is the first report of separate genetic loci controlling cell wall phenotypes above and below ground. These results suggest that it may be possible to modify lignin content and composition via breed and/or engineer as a means of simultaneously improving Populus for cellulosic ethanol production and carbon sequestration.
在这项研究中，我们建立了一个包含大量三代杂交杨杂种后代的综合遗传图谱，并对作图个体的茎和根进行了木质素含量、S/G 比和 28 个细胞壁亚组分的表型分析。表型分析表明，利用热解分子束质谱法（pyMBMS）测定的木质素含量和愈创木基/丁香基（S/G）比值在作图个体中存在差异。结果表明，茎木质素含量显著高于根木质素含量，并且所定量的性状可分为四个不同的组，器官内各成分之间存在很强的相关性。共检测到 179 个协调 QTL，并将其共定位到 49 个遗传位点，其中 27 个似乎是多效的。许多检测到的遗传位点在茎和根中表现出不同的遗传控制。这是第一个报道地上和地下细胞壁表型分别由独立遗传位点控制的报告。这些结果表明，通过选育和/或工程手段改变木质素含量和组成可能是同时提高杨树纤维素乙醇产量和碳固存能力的一种方法。
