Chen Zhe, Yan Tingting, Abbas Farhat, Yang Mingchao, Wang Xianghe, Deng Hao, Zhang Hongna, Hu Fuchu
Institute of Tropical Fruit Trees, Hainan Academy of Agricultural Sciences/Key Laboratory of Genetic Resources Evaluation and Utilization of Tropical Fruits and Vegetables (Co-Construction by Ministry and Province), Ministry of Agriculture and Rural Affairs/Key Laboratory of Tropical Fruit Tree Biology of Hainan Province, Haikou 571100, China.
Sanya Research Institute, Hainan Academy of Agricultural Sciences, Sanya 572025, China.
Plants (Basel). 2024 Sep 16;13(18):2592. doi: 10.3390/plants13182592.
Litchi exhibits a large number of flowers, many flowering batches, and an inconsistent ratio of male and female flowers, frequently leading to a low fruit-setting rate. Floral sexual differentiation is a crucial phase in perennial trees to ensure optimal fruit production. However, the mechanism behind floral differentiation remains unclear. The objective of the study was to identify the role of auxin in floral differentiation at the transcriptional level. The results showed that the ratio of female flowers treated with naphthalene acetic acid (NAA) was significantly lower than that of the control stage (M0/F0). The levels of endogenous auxin and auxin metabolites were measured in male and female flowers at different stages of development. It was found that the levels of IAA, IAA-Glu, IAA-Asp, and IAA-Ala were significantly higher in male flowers compared to female flowers. Next-generation sequencing and modeling were employed to perform an in-depth transcriptome analysis on all flower buds in litchi 'Feizixiao' cultivars ( Sonn.). Plant hormones were found to exert a significant impact on the litchi flowering process and flower proliferation. Specifically, a majority of differentially expressed genes (DEGs) related to the auxin pathway were noticeably increased during male flower bud differentiation. The current findings will enhance our comprehension of the process and control mechanism of litchi floral sexual differentiation. It also offers a theoretical foundation for implementing strategies to regulate flowering and enhance fruit production in litchi cultivation.
荔枝花量大、开花批次多，且雌雄花比例不协调，常导致坐果率低。花的性别分化是多年生树木确保最佳果实产量的关键阶段。然而，花分化背后的机制仍不清楚。本研究的目的是在转录水平上确定生长素在花分化中的作用。结果表明，用萘乙酸（NAA）处理的雌花比例显著低于对照阶段（M0/F0）。在发育的不同阶段对雄花和雌花中的内源生长素和生长素代谢物水平进行了测定。结果发现，雄花中IAA、IAA-Glu、IAA-Asp和IAA-Ala的水平显著高于雌花。采用二代测序和建模对荔枝‘妃子笑’品种（Sonn.）的所有花芽进行深入的转录组分析。发现植物激素对荔枝开花过程和花的增殖有显著影响。具体而言，在雄花芽分化过程中，大多数与生长素途径相关的差异表达基因（DEG）显著增加。目前的研究结果将增进我们对荔枝花性别分化过程和调控机制的理解。它也为实施调控荔枝开花和提高果实产量的策略提供了理论基础。
