Table_4_A Genome-Wide Association Study Identifies New Loci Involved in Wound-Induced Lateral Root Formation in Arabidopsis thaliana.DOCX

Root systems can display variable architectures that contribute to nutrient foraging or to increase the tolerance of abiotic stress conditions. Root tip excision promotes the developmental progression of previously specified lateral root (LR) founder cells, which allows to easily measuring the branching capacity of a given root as regards its genotype and/or growth conditions. Here, we describe the natural variation among 120 Arabidopsis thaliana accessions in root system architecture (RSA) after root tip excision. Wound-induced changes in RSA were associated with 19 genomic loci using genome-wide association mapping. Three candidate loci associated with wound-induced LR formation were investigated. Sequence variation in the hypothetical protein encoded by the At4g01090 gene affected wound-induced LR development and its loss-of-function mutants displayed a reduced number of LRs after root tip excision. Changes in a histidine phosphotransfer protein putatively involved in cytokinin signaling were significantly associated with LR number variation after root tip excision. Our results provide a better understanding of some of the genetic components involved in LR capacity variation among accessions.

根系统可呈现出多样化的结构，这些结构有助于营养物质的获取或增强对非生物胁迫条件的耐受性。通过切除根尖，可促进先前指定的侧根（LR）原基细胞的发育进程，从而便于测量特定根系的分叉能力，并评估其基因型和/或生长条件。在本研究中，我们对120个拟南芥（Arabidopsis thaliana）基因型在根系统结构（RSA）方面的自然变异进行了描述，并分析了切除根尖后的情况。通过全基因组关联分析，发现与RSA变化相关的19个基因组位点。研究还深入探究了与伤口诱导的LR形成相关的三个候选位点。由At4g01090基因编码的假设蛋白的序列变异影响了伤口诱导的LR发育，其功能缺失突变体在根尖切除后表现出LR数量减少。参与细胞分裂素信号传导的组氨酸磷酸转移蛋白的变化与根尖切除后LR数量变异显著相关。我们的研究结果加深了对基因型间LR能力变异所涉及的遗传成分的理解。