Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China.
Center for Computational Biology, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China.
Tree Physiol. 2020 Dec 5;40(12):1762-1777. doi: 10.1093/treephys/tpaa098.
Callus differentiation is a key developmental process in plant regeneration from cells. A better understanding of the genetic architecture of callus differentiation timing can help improve tissue transformation and the efficiency of artificial propagation. In this study, we investigated genotypic variation in callus differentiation capacity among 297 diverse P. euphratica trees sampled from a natural population. We employed a genome-wide association study (GWAS) of binary and growth-based parameters to identify loci and characterize the genetic architecture and genetic network underlying regulation of callus differentiation in P. euphratica. The results of this GWAS experiment suggested potential associations controlling whether the callus could differentiate and the process of callus differentiation. We identified multiple significant quantitative trait loci (QTLs), including the genes LOG1 and LOG7 and a locus containing WOX1. We reconstructed a genetic network that visualizes how each QTL interacts uniquely with other variants, and several core QTLs were detected that are involved in the degree of callus differentiation, providing potential targets for selection. This study represents one of the first to identify genetic variants affecting callus differentiation in a forest tree. Our results suggest that callus differentiation may be a typical qualitative-quantitative trait controlled by a major gene as well as polygenes across the genome of P. euphratica. This GWAS will help to design more complex and specific molecular tools for systematically manipulating organ regeneration.
愈伤组织分化是植物细胞再生过程中的一个关键发育过程。更好地了解愈伤组织分化时间的遗传结构可以帮助提高组织转化和人工繁殖的效率。在这项研究中，我们研究了从天然种群中采样的 297 棵不同的胡杨树木中愈伤组织分化能力的基因型变异。我们采用了基于二进制和生长的参数的全基因组关联研究（GWAS），以鉴定控制愈伤组织分化的基因座，并描述胡杨愈伤组织分化调控的遗传结构和遗传网络。该 GWAS 实验的结果表明，控制愈伤组织能否分化以及愈伤组织分化过程的潜在关联。我们确定了多个显著的数量性状位点（QTL），包括 LOG1 和 LOG7 基因以及包含 WOX1 的基因座。我们重建了一个遗传网络，可视化了每个 QTL 如何与其他变体独特地相互作用，并且检测到了几个核心 QTL，这些 QTL 涉及愈伤组织分化的程度，为选择提供了潜在的目标。这项研究是首次鉴定影响森林树木愈伤组织分化的遗传变异之一。我们的结果表明，愈伤组织分化可能是由主基因以及基因组中的多基因共同控制的典型质量-数量性状。该 GWAS 将有助于设计更复杂和特定的分子工具，用于系统地操纵器官再生。
