Table_2_A Genome-Wide Association Study Identifies New Loci Involved in Wound-Induced Lateral Root Formation in Arabidopsis thaliana.XLSX

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.

根系可形成多样化的构型，此类构型有助于植物获取养分并提升其对非生物胁迫的耐受能力。切除根尖能够促进预先特化的侧根（Lateral Root, LR）起始细胞的发育进程，从而可便捷地测定特定根系在不同基因型或生长条件下的分枝能力。本研究报道了120份拟南芥（Arabidopsis thaliana）生态型在根尖切除后的根系构型（Root System Architecture, RSA）自然变异特征。通过全基因组关联分析（genome-wide association mapping），我们将伤口诱导的根系构型变化关联至19个基因组位点。我们对3个与伤口诱导侧根形成相关的候选位点展开了研究：由At4g01090基因编码的假想蛋白的序列变异会影响伤口诱导的侧根发育，其功能缺失突变体（loss-of-function mutants）在根尖切除后的侧根数量显著降低；一个可能参与细胞分裂素信号通路（cytokinin signaling）的组氨酸磷酸转移蛋白（histidine phosphotransfer protein）的序列变异，与根尖切除后的侧根数量变异呈显著相关。本研究结果为解析不同生态型间侧根形成能力变异的部分遗传组分提供了更深入的认知。