植物激素信号通路参与调控黄花菜花蕾大小的作用机制

Plant hormone signaling is involved in regulating flower bud size of daylily

摘要:

为了探讨植物激素在调控黄花菜花蕾大小发育过程中的作用及代谢差异，采集了‘大同黄花’和‘东北黄花’幼蕾期、绿期、转黄期、黄期共4个时期的花蕾，开展了转录组测序、差异表达基因分析和喷施激素验证分析。结果表明，在‘大同黄花’和‘东北黄花’花蕾不同发育时期中，共筛选出199个植物激素生物合成代谢相关的差异表达基因，分别调控脱落酸、赤霉素、生长素、茉莉酸、细胞分裂素和乙烯这6种植物激素的合成代谢，其中生长素差异表达基因数量最多，表明生长素可能在调控花蕾发育中具有重要的作用。生长素响应因子(auxin response factor,ARF)在花蕾发育的4个时期均处于上调状态，说明ARF在黄花菜花蕾发育的整个阶段都起到正向调控作用；通过外源喷施6种激素，进一步验证了吲哚-3-乙酸(indole-3-acetic acid,IAA)显著促进‘大同黄花’花蕾的生长和营养成分的提高，因此推测IAA对调控花蕾发育具有重要的作用。研究结果为进一步研究‘大同黄花’与‘东北黄花’花蕾发育的调控机制奠定了理论基础。

Abstract:

To explore the role and metabolic differences of plant hormones in regulating the flower bud size of daylily, we collected the flower buds from two daylily varieties ‘Datong Huanghua’ and ‘Dongbei Huanghua’ at the young bud, green, yellowing, and yellow stages for transcriptome sequencing. The differentially expressed genes (DEGs) were screened, and the exogenous plant hormone spraying experiments were conducted. A total of 199 DEGs related to the biosynthesis and metabolism of plant hormones was screened out at different flower development stages of ‘Datong Huanghua’ and ‘Dongbei Huanghua’. These genes regulated the biosynthesis and metabolism of six plant hormones: abscisic acid, gibberellin, auxin, jasmonate, cytokinin, and ethylene. The DEGs associated with auxin were the most, which suggested that auxin played a role in regulating flower bud development. The auxin response factor (ARF) presented up-regulated expression at all the four stages of flower bud development, indicating that ARF played a positive regulatory role throughout the flower bud development of daylily. The experiments with exogenous spraying of six hormones further verified that indole-3-acetic acid (IAA) significantly promoted the growth and increased the nutrient content in the flower buds of ‘Datong Huanghua’, suggesting that IAA played a role in regulating flower bud development. Our results laid a theoretical foundation for probing into the regulatory mechanism of flower bud development of ‘Datong Huanghua’ and ‘Dongbei Huanghua’.