J Exp Bot:中科院植物所贺超英研究组发表大豆种子大小变异调控与
2017年5月2日，国际植物学知名刊物《Journal of Experimental Botany》上在线发表了中国科学院植物研究所贺超英研究组题为“Differential expression of a WRKY gene between wild and cultivated soybeans correlates to seed size”的研究论文。贺超英研究组的博士研究生谷勇哲、黑龙江省农科院耕作栽培所李炜和东北农业大学博士蒋洪蔚为论文共同第一作者，贺超英为论文通讯作者。
栽培大豆(Glycine max)由野大豆(Glycine soja)驯化而来。在这一驯化过程中大豆种子显著变大，但目前人们对造成这一差异的遗传变异了解不多。
贺超英研究组发现，位于种子大小相关的QTL位点区间内的SoyWRKY15a基因在栽培大豆SN14和野大豆ZYD00006间存在差异表达。群体分析表明该基因在栽培大豆中的位点GmWRKY15a和野大豆中的位点GsWRKY15a编码区序列完全一致，但GmWRKY15a在果实中的表达量显著高于GsWRKY15a，且GsWRKY15a的表达量和调控区单倍型变异均与种子大小显著相关，暗示其可调控种子大小。进一步分析发现，SoyWRKY15a的5′非翻译区(5′UTR)中CT的重复数目变异影响了它的表达量，而该调控区单倍型的变异式样则表明该基因很可能与大豆的驯化有关。这一研究首次发现了WRKY转录因子基因可能参与调控大豆种子大小，为解析大豆种子大小的遗传变异基础及理解大豆驯化过程和机制提供了新的思路。
图：SoyWRKY15a参与大豆种子大小的驯化。(A)栽培大豆SN14和野大豆ZYD00006的种子;(B)SoyWRKY15a在大豆果实中的表达与百粒重的关系;(C)SoyWRKY15a调控区单倍型变异情况;(D)野大豆SoyWRKY15a单倍型变异与种子大小。
原文链接：
Differential expression of a WRKY GENE between wild and cultivated soybeans correlates to seed size
原文摘要：
Soybean (Glycine max) probably originated from the wild soybean (Glycine soja).Glycine max has a significantly larger seed size, but the underlying genomic changes are largely unknown. Candidate regulatory genes were preliminarily proposed by data co-localizing RNA sequencing with the quantitative loci (QTLs) for seed size. The soybean gene locus SoyWRKY15a and its orthologous genes from G. max (GmWRKY15a) and G. soja (GsWRKY15a) were analyzed in detail. The coding sequences were nearly identical between the two orthologs, but GmWRKY15a was significantly more highly expressed than GsWRKY15a. Four haplotypes (H1–H4) were found and they varied in the size of a CT-core microsatellite locus in the 5'-untranslated region of this gene. H1 (with six CT-repeats) was the only allelic version found in G. max, while H3 (with five CT-repeats) was the dominant G. soja allele. Differential expression of this gene in soybean pods was correlated with CT-repeat variation, and manipulation of the CT copy number altered the reporter gene expression, suggesting a regulatory role for the simple sequence repeats. Seed weight of wild soybeans harboring H1 was significantly greater than that of soybeans having haplotypes H2, H3, or H4, and seed weight was correlated with gene expression, suggesting the influence of GsWRKY15a in controlling seed size. However, the seed size might be refractory to increased SoyWRKY15aexpression in cultivated soybeans. The evolutionary significance ofSoyWRKY15a variation in soybean seed domestication is discussed.
作者：贺超英
