Institute of Evolution, University of Haifa, Haifa, 3498838, Israel.
Department of Evolutionary and Environmental Biology, University of Haifa, 199 Abba-Khoushy Ave, Mt. Carmel, Haifa, 3498838, Israel.
Plant J. 2020 Feb;101(3):555-572. doi: 10.1111/tpj.14554. Epub 2019 Nov 10.
Dissection of the genetic basis of wheat ionome is crucial for understanding the physiological and biochemical processes underlying mineral accumulation in seeds, as well as for efficient crop breeding. Most of the elements essential for plants are metals stored in seeds as chelate complexes with phytic acid or sulfur-containing compounds. We assume that the involvement of phosphorus and sulfur in metal chelation is the reason for strong phenotypic correlations within ionome. Adjustment of element concentrations for the effect of variation in phosphorus and sulfur seed content resulted in drastic change of phenotypic correlations between the elements. The genetic architecture of wheat grain ionome was characterized by quantitative trait loci (QTL) analysis using a cross between durum and wild emmer wheat. QTL analysis of the adjusted traits and two-trait analysis of the initial traits paired with either P or S considerably improved QTL detection power and accuracy, resulting in the identification of 105 QTLs and 617 QTL effects for 11 elements. Candidate gene search revealed some potential functional associations between QTLs and corresponding genes within their intervals. Thus, we have shown that accounting for variation in P and S is crucial for understanding of the physiological and genetic regulation of mineral composition of wheat grain ionome and can be implemented for other plants.
解析小麦离子组的遗传基础对于理解种子中矿物质积累的生理生化过程以及进行高效的作物育种至关重要。大多数对植物必不可少的元素都是以与植酸或含硫化合物形成螯合物的形式储存在种子中的金属。我们假设磷和硫参与金属螯合是离子组内强表型相关性的原因。调整元素浓度以消除磷和硫种子含量变化的影响，导致元素之间的表型相关性发生剧烈变化。利用硬粒小麦和野生二粒小麦的杂交进行数量性状位点（QTL）分析，对小麦籽粒离子组的遗传结构进行了表征。调整后的性状的 QTL 分析以及与 P 或 S 配对的初始性状的双性状分析极大地提高了 QTL 检测的能力和准确性，从而鉴定出 11 个元素的 105 个 QTL 和 617 个 QTL 效应。候选基因搜索揭示了 QTL 与其区间内相应基因之间的一些潜在功能关联。因此，我们表明，考虑 P 和 S 的变化对于理解小麦籽粒离子组矿物质组成的生理和遗传调控至关重要，并且可以应用于其他植物。
