Department of Horticulture, Shenyang Agricultural University, 120 Dongling Road, Shenhe District, Shenyang 110866, China.
Int J Mol Sci. 2019 May 10;20(9):2310. doi: 10.3390/ijms20092310.
Petal color, size, and morphology play important roles in protecting other floral organs, attracting pollinators, and facilitating sexual reproduction in plants. In a previous study, we obtained a petal degeneration mutant () from the 'FT' doubled haploid line of Chinese cabbage and found that the candidate gene for , , encodes the enzyme acyl-CoA oxidase1. In this study, we sought to examine the gene networks regulating petal development in plants. We show that the mRNA and protein expression of , which is involved in the jasmonic acid (JA) biosynthetic pathway, were significantly lower in the petals of plants than in those of 'FT' plants. Similarly, the JA and methyl jasmonate (MeJA) contents of petals were significantly lower in plants than in 'FT' plants and we found that exogenous application of these hormones to the inflorescences of plants restored the 'FT' phenotype. Comparative analyses of the transcriptomes of 'FT', and + JA (pJA) plants revealed 10,160 differentially expressed genes (DEGs) with consistent expression tendencies in 'FT' vs. and pJA vs. comparisons. Among these DEGs, we identified 69 DEGs related to floral organ development, 11 of which are involved in petal development regulated by JA. On the basis of qRT-PCR verification, we propose regulatory pathways whereby JA may mediate petal development in the mutant. We demonstrate that mutation of in plants leads to reduced JA levels and that this in turn promotes changes in the expression of genes that are expressed in response to JA, ultimately resulting in petal degeneration. These findings thus indicate that JA is associated with petal development in Chinese cabbage. These results enhance our knowledge on the molecular mechanisms underlying petal development and lay the foundations for further elucidation of the mechanisms associated with floral organ development in Chinese cabbage.
花瓣的颜色、大小和形态在保护其他花卉器官、吸引传粉者和促进植物有性繁殖方面起着重要作用。在之前的研究中，我们从白菜 'FT' 双倍单倍体系中获得了一个花瓣退化突变体 ()，并发现候选基因 ，编码酰基辅酶 A 氧化酶 1。在本研究中，我们试图研究调控 植物花瓣发育的基因网络。我们表明，参与茉莉酸 (JA) 生物合成途径的 的 mRNA 和蛋白质表达在 植物的花瓣中明显低于 'FT' 植物。同样，花瓣中的 JA 和茉莉酸甲酯 (MeJA) 含量在 植物中也明显低于 'FT' 植物，我们发现这些激素外源施加到 植物的花序上恢复了 'FT' 表型。对 'FT'、 和 + JA (pJA) 植物的转录组进行比较分析，发现了 10160 个具有一致表达趋势的差异表达基因 (DEGs)。在这些 DEGs 中，我们鉴定了 69 个与花器官发育相关的 DEGs，其中 11 个参与了 JA 调控的花瓣发育。基于 qRT-PCR 验证，我们提出了 JA 可能介导 突变体花瓣发育的调控途径。我们证明 突变导致 JA 水平降低，这反过来又促进了对 JA 有反应的基因的表达变化，最终导致花瓣退化。这些发现表明 JA 与白菜花瓣发育有关。这些结果增强了我们对花瓣发育分子机制的认识，并为进一步阐明白菜花器官发育的机制奠定了基础。
