College of Horticulture, Hebei Agricultural University, Baoding, China.
Hebei Key Laboratory of Vegetable Germplasm Innovation and Utilization, Baoding, China.
PeerJ. 2022 Mar 9;10:e13088. doi: 10.7717/peerj.13088. eCollection 2022.
Melon ( L.) is an agronomically important vegetable. Most cultivars of melon are andromonoecious and bisexual flowers only emerged from the leaf axil of lateral branches. However, the regulatory mechanism contributing to the occurrence of bisexual flowers were still obscure. In this study, ethephon was applied in two common cultivars of melon. In control without ethephon treatment, no bisexual flower was made in the main stem. However, 6.56 ± 1.42 and 6.63 ± 0.55 bisexual flowers were respectively induced in main stem of 'Yangjiaocui-QX' and 'Lvbao' after ethephon treatment, and induced bisexual flowers distributed in 12-20 nodes of main stem. During the formation of bisexual flowers, 41 metabolites were significantly up-regulated and 98 metabolites were significantly down-regulated. According to the KEGG enrichment analysis of 139 different metabolites, a total of 30 pathways were mapped and KEGG terms of "Phenylalanine, tyrosine and tryptophan biosynthesis", "Phenylalanine metabolism" and "Flavone and flavonol biosynthesis" were significantly enriched. In three significantly enriched KEGG terms, shikimic acid, L-tryptophan, L-phenylalanine, and kaempferol were significantly up-regulated while L-tyrosine, 4-hydroxycinnami acid and luteolin were significantly down-regulated in ET compared to CK. Different metabolites were also classified depend on major class features and 14 classes were acquired. The results of metabonomics and endogenous hormone identification indicated that ethylene could enhance the concentration of salicylic acid, methyl jasmonate, ABA and IAA. This study provided an important theoretical foundation for inducing bisexual flowers in main stem and breeding new varieties of melon in future.
甜瓜（L.）是一种重要的农业蔬菜。大多数甜瓜品种都是雌雄同株，两性花仅从侧枝叶腋处萌发。然而，导致两性花出现的调控机制仍不清楚。本研究在两个常见的甜瓜品种上使用了乙烯利。在没有乙烯利处理的对照中，主茎上没有出现两性花。然而，在‘羊角脆-QX’和‘绿宝’主茎上分别用乙烯利处理后，诱导出了 6.56±1.42 和 6.63±0.55 朵两性花，诱导的两性花分布在主茎的 12-20 节上。在两性花的形成过程中，有 41 种代谢物显著上调，98 种代谢物显著下调。根据 139 种不同代谢物的 KEGG 富集分析，共映射到 30 条途径，KEGG 术语“苯丙氨酸、酪氨酸和色氨酸生物合成”、“苯丙氨酸代谢”和“黄酮和黄酮醇生物合成”显著富集。在三个显著富集的 KEGG 术语中，与 CK 相比，ET 中莽草酸、L-色氨酸、L-苯丙氨酸和山奈酚显著上调，而 L-酪氨酸、4-羟基肉桂酸和木樨草素显著下调。根据主要类别的特征，不同的代谢物也进行了分类，获得了 14 个类别。代谢组学和内源激素鉴定的结果表明，乙烯可以提高水杨酸、茉莉酸甲酯、ABA 和 IAA 的浓度。本研究为诱导主茎两性花和未来培育甜瓜新品种提供了重要的理论基础。
