DataSheet8_Nucleotide polymorphisms of the maize ZmFWL7 gene and their association with ear-related traits.ZIP

Plant fw2.2-like (FWL) genes, encoding proteins harboring a placenta-specific eight domain, have been suggested to control fruit and grain size through regulating cell division, differentiation, and expansion. Here, we re-sequenced the nucleotide sequences of the maize ZmFWL7 gene, a member of the FWL family, in 256 elite maize inbred lines, and the associations of nucleotide polymorphisms in this locus with 11 ear-related traits were further detected. A total of 175 variants, including 159 SNPs and 16 InDels, were identified in the ZmFWL7 locus. Although the promoter and downstream regions showed higher nucleotide polymorphism, the coding region also possessed 61 SNPs and 6 InDels. Eleven polymorphic sites in the ZmFWL7 locus were found to be significantly associated with eight ear-related traits. Among them, two nonsynonymous SNPs (SNP2370 and SNP2898) showed significant association with hundred kernel weight (HKW), and contributed to 7.11% and 8.62% of the phenotypic variations, respectively. In addition, the SNP2898 was associated with kernel width (KW), and contributed to 7.57% of the phenotypic variations. Notably, the elite allele T of SNP2370 was absent in teosintes and landraces, while its frequency in inbred lines was increased to 12.89%. By contrast, the frequency of the elite allele A of SNP2898 was 3.12% in teosintes, and it was raised to 12.68% and 19.92% in landraces and inbred lines, respectively. Neutral tests show that this locus wasn’t artificially chosen during the process of domestication and genetic improvement. Our results revealed that the elite allelic variants in ZmFWL7 might possess potential for the genetic improvement of maize ear-related traits.

编码含有胎盘特异性八结构域蛋白的fw2.2类（fw2.2-like, FWL）基因，被认为通过调控细胞分裂、分化与扩张来控制果实与籽粒大小。本研究对256份优良玉米自交系中的FWL家族成员ZmFWL7基因的核苷酸序列进行了重测序，并进一步检测了该基因座的核苷酸多态性与11个穗部相关性状的关联。共计在ZmFWL7基因座中鉴定到175个变异位点，包括159个单核苷酸多态性（Single Nucleotide Polymorphism, SNP）与16个插入缺失（Insertion-Deletion, InDel）。尽管启动子与下游区域的核苷酸多态性更高，但编码区仍存在61个SNP与6个InDel。研究发现ZmFWL7基因座中有11个多态性位点与8个穗部相关性状显著关联。其中，两个错义SNP（SNP2370与SNP2898）与百粒重（hundred kernel weight, HKW）显著相关，分别解释了7.11%与8.62%的表型变异。此外，SNP2898还与粒宽（kernel width, KW）相关，解释了7.57%的表型变异。值得注意的是，SNP2370的优良等位基因T在大刍草与地方品种中均未检出，而在自交系中的频率提升至12.89%。与之相反，SNP2898的优良等位基因A在大刍草中的频率为3.12%，在地方品种与自交系中分别升至12.68%与19.92%。中性检验结果显示，该基因座在驯化与遗传改良过程中并未受到人工选择。本研究结果表明，ZmFWL7基因的优良等位变异可为玉米穗部相关性状的遗传改良提供潜在应用价值。