Plasticity of root anatomy during domestication of a maize-teosinte derived population
Plasticity of root anatomy during domestication of a maize-teosinte derived population
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DOI：
10.1093/jxb/erab406
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发表时间：
2021-09-06
影响因子：
6.9
通讯作者：
Pan, Qingchun
中科院分区：
文献类型：
--
作者：
Chen, Zhe;Sun, Junli;Pan, Qingchun
玉米(Zea Mays L.)在驯化过程中，根的解剖结构发生了深刻的变化，以适应环境。然而，玉米根系解剖在驯化过程中可塑性的遗传机制尚不清楚。在这项研究中，使用一个玉米-teosinte群体(Miciana X Mo17)在三个环境中对九个根系解剖性状进行了高分辨率定位。不同的根系解剖性状存在较大的遗传变异。皮层、中柱、透气组织面积、木质部维管数和皮层细胞数在三种环境中都有较大差异，表明可塑性较强。共检测到16个数量性状座位(QTL)，其中7个为高塑性性状的QTL×环境互作(EIQTL)，9个为无QTL×环境互作(SQTL)。大多数根位点与描述驯化信号的地上部QTL一致。结合转录组和全基因组关联研究表明，生长素外排载体PIN形成的类4(ZmPILS4)是木质部性状的一个主要QTL的候选基因。ZmPILS4低表达的近等基因系根尖生长素浓度高18-24%，木质部维管数高8-15%。启动子区域的核苷酸差异值分析表明，ZmPILS4参与了玉米的驯化适应。这些结果揭示了驯化过程中根系解剖可塑性的潜在遗传基础。
Maize (Zea mays L.) has undergone profound changes in root anatomy for environmental adaptation during domestication. However, the genetic mechanism of plasticity of maize root anatomy during the domestication process remains unclear. In this study, high-resolution mapping was performed for nine root anatomical traits using a maize-teosinte population (mexicana x Mo17) across three environments. Large genetic variations were detected for different root anatomical traits. The cortex, stele, aerenchyma areas, xylem vessel number, and cortical cell number had large variations across three environments, indicating high plasticity. Sixteen quantitative trait loci (QTL) were identified, including seven QTL with QTL x environment interaction (EIQTL) for high plasticity traits and nine QTL without QTL x environment interaction (SQTL). Most of the root loci were consistent with shoot QTL depicting domestication signals. Combining transcriptome and genome-wide association studies revealed that AUXIN EFFLUX CARRIER PIN-FORMED LIKE 4 (ZmPILS4) serves as a candidate gene underlying a major QTL of xylem traits. The near-isogenic lines (NILs) with lower expression of ZmPILS4 had 18-24% more auxin concentration in the root tips and 8-15% more xylem vessels. Nucleotide diversity values analysis in the promoter region suggested that ZmPILS4 was involved in maize domestication and adaptation. These results revealed the potential genetic basis of root anatomical plasticity during domestication.