Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, College of Horticulture, China Agricultural University, Beijing 100193, China.
Flower Research Institute, Yunnan Academy of Agricultural Sciences, Kunming 650205, China.
Genes (Basel). 2022 Jun 10;13(6):1041. doi: 10.3390/genes13061041.
Flower size, a primary agronomic trait in breeding of ornamental plants, is largely determined by petal expansion. Generally, ethylene acts as an inhibitor of petal expansion, but its effect is restricted by unknown developmental cues. In this study, we found that the critical node of ethylene-inhibited petal expansion is between stages 1 and 2 of rose flower opening. To uncover the underlying regulatory mechanism, we carried out a comparative RNA-seq analysis. Differentially expressed genes (DEGs) involved in auxin-signaling pathways were enriched. Therefore, we identified an auxin/indole-3-acetic acid (Aux/IAA) family gene, , whose expression was development-specifically repressed by ethylene. The silencing of reduced cell expansion, resulting in diminished petal expansion and flower size. In addition, the expressions of cell-expansion-related genes, including , , and , were significantly downregulated following silencing. Our results reveal an Aux/IAA that serves as a key player in orchestrating petal expansion and ultimately contributes to flower size, which provides new insights into ethylene-modulated flower opening and the function of the Aux/IAA transcription regulator.
花朵大小是观赏植物育种中的一个主要农艺性状，主要由花瓣扩张决定。通常，乙烯作为花瓣扩张的抑制剂起作用，但它的作用受到未知发育线索的限制。在这项研究中，我们发现乙烯抑制花瓣扩张的关键节点在玫瑰开花的 1 期和 2 期之间。为了揭示潜在的调控机制，我们进行了比较 RNA-seq 分析。涉及生长素信号通路的差异表达基因（DEGs）被富集。因此，我们鉴定了一个生长素/吲哚-3-乙酸（Aux/IAA）家族基因 ，其表达受乙烯特异性抑制。 的沉默减少了细胞扩张，导致花瓣扩张和花朵大小减小。此外，细胞扩张相关基因的表达，包括 、 、 和 ，在 沉默后显著下调。我们的结果揭示了一个 Aux/IAA，它作为协调花瓣扩张的关键因子，最终有助于花朵大小，为乙烯调节开花和 Aux/IAA 转录调节剂的功能提供了新的见解。
