Des Marais David L, Razzaque Samsad, Hernandez Kyle M, Garvin David F, Juenger Thomas E
Department of Integrative Biology and Institute for Cell and Molecular Biology, The University of Texas at Austin, United States.
Department of Integrative Biology and Institute for Cell and Molecular Biology, The University of Texas at Austin, United States.
Plant Sci. 2016 Oct;251:2-11. doi: 10.1016/j.plantsci.2016.03.010. Epub 2016 Mar 24.
All plants must optimize their growth with finite resources. Water use efficiency (WUE) measures the relationship between biomass acquisition and transpired water. In the present study, we performed two experiments to understand the genetic basis of WUE and other parameters of plant-water interaction under control and water-limited conditions. Our study used two inbred natural accessions of Brachypodium distachyon, a model grass species with close phylogenetic affinity to temperate forage and cereal crops. First, we identify the soil water content which causes a reduction in leaf relative water content and an increase in WUE. Second, we present results from a large phenotyping experiment utilizing a recombinant inbred line mapping population derived from these same two natural accessions. We identify QTLs associated with environmentally-insensitive genetic variation in WUE, including a pair of epistatically interacting loci. We also identify QTLs associated with constitutive differences in biomass and a QTL describing an environmentally-sensitive difference in leaf carbon content. Finally, we present a new linkage map for this mapping population based on new SNP markers as well as updated genomic positions for previously described markers. Our studies provide an initial characterization of plant-water relations in B. distachyon and identify candidate genomic regions involved in WUE.
所有植物都必须利用有限的资源来优化自身生长。水分利用效率（WUE）衡量的是生物量获取与蒸腾水分之间的关系。在本研究中，我们进行了两项实验，以了解在对照条件和水分受限条件下WUE的遗传基础以及植物 - 水分相互作用的其他参数。我们的研究使用了两种二穗短柄草的自交系天然种质，二穗短柄草是一种与温带牧草和谷类作物具有密切系统发育亲缘关系的模式草种。首先，我们确定了导致叶片相对含水量降低和WUE增加的土壤含水量。其次，我们展示了一项大型表型实验的结果，该实验利用了来自这两种相同天然种质的重组自交系作图群体。我们鉴定了与WUE中对环境不敏感的遗传变异相关的数量性状基因座（QTL），包括一对上位性相互作用位点。我们还鉴定了与生物量的组成差异相关的QTL以及一个描述叶片碳含量中环境敏感差异的QTL。最后，我们基于新的单核苷酸多态性（SNP）标记以及先前描述标记的更新基因组位置，为该作图群体绘制了一张新的连锁图谱。我们的研究提供了二穗短柄草中植物 - 水分关系的初步特征，并鉴定了参与WUE的候选基因组区域。
