School of Life Sciences, Qufu Normal University, Qufu, 273165, Shandong, China.
J Plant Res. 2022 May;135(3):465-472. doi: 10.1007/s10265-022-01379-8. Epub 2022 Feb 21.
Gaillardia plants have been widely cultivated in China and have become an important component of garden landscaping. Different from the common ligulate ray floret, the cornflower-like (funnel-shaped) ray floret is a special phenotype variation in Gaillardia species. Previous studies revealed that CYC-like genes could shape the floret phenotype in Compositae. To reveal the molecular mechanism of the cornflower-like phenotype, we checked the capitulum transcriptomes of several cultivars of Gaillardia that possess different ray florets. As a result, we identified 11 CYC-like genes, of which five included complete coding region sequences. Phylogenetic analysis revealed that all five genes were CYC2-like genes. Relative expression analysis of RNA-resequencing reads, qRT-PCR comparison, and gene-silencing treatment all showed that the CYC2c gene is the main genetic mechanism responsible for the shaping of the cornflower-like ray floret phenotype in Gaillardia cultivars. This study expounded our understanding of flower morphology evolution and provides useful insights for improving Compositae breeding.
矢车菊属植物在中国被广泛种植，已成为园林景观的重要组成部分。不同于常见的舌状管瓣花，管状（漏斗状）管瓣花是矢车菊属植物的一种特殊表型变异。先前的研究表明，CYC 样基因可以影响菊科植物花的形态。为了揭示管状花表型的分子机制，我们检查了具有不同管状花花型的几种矢车菊品种的头状花序转录组。结果，我们鉴定出了 11 个 CYC 样基因，其中 5 个包含完整的编码区序列。系统发育分析表明，这 5 个基因均为 CYC2 样基因。RNA-seq 测序的相对表达分析、qRT-PCR 比较和基因沉默处理均表明，CYC2c 基因是决定矢车菊品种管状花表型的主要遗传机制。本研究阐述了我们对花形态进化的理解，为改进菊科植物的育种提供了有用的见解。
