School of Modern Industry for Selenium Science and Engineering, Wuhan Polytechnic University, Wuhan 430048, China.
Int J Mol Sci. 2022 Jun 9;23(12):6452. doi: 10.3390/ijms23126452.
Chestnut () is an important woody food crop, but its yield has been low in cultivation, mainly due to the problems of fewer female flowers and more male flowers. Therefore, regulating the transition of chestnut flowers and effectively balancing the proportion of male and female to improve the yield are key factor to be solved in production. In this study, the chestnut floral buds in pre- and post-winter were used as materials. The data of metabolites, hormones, and gene expression during flower bud differentiation of chestnut were analyzed by transcriptomics and metabolomics to preliminarily reveal the possible reason of male and female flower bud transformation in pre- and post-winter. The analysis of Differentially Expressed Genes (DEGs) showed that there were 6323 DEGs in the Complete mixed flower bud (CMF) group in pre- and post-winter, of which 3448 genes were up-regulated and 2875 genes were down-regulated. There were 8037 DEGs in the Incomplete mixed flower bud (IMF) in pre- and post-winter, of which 4546 genes were up-regulated and 3491 genes were down-regulated. A total of 726 genes from the two flower buds were enriched into 251 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in post winter, of which plant hormone signal transduction accounted for 4.13%. The analysis results of differential metabolites showed that the differential metabolites of the two flower buds were mainly concentrated in the secondary metabolic synthesis pathway. The difference of hormone content showed that the content of Gibberellin 9 (GA9) and GA19 in CMF was higher than that in IMF in pre-winter, but the opposite in post-winter. Methyl jasmonate (MeJA) content was only very high in CMF in pre-winter, while Jasmonoyl-(l)-Isoleucine (JA-ILE) showed high content in CMF in post-winter. In post-winter, higher concentration of JA-ILE was positively correlated with the expression of Flowering Locus T (), and gene was significantly positively correlated with the expression levels of , and (LEAFY 3). The higher concentration of JA-ILE was negatively correlated with the transcription level of . In vitro experiments further verified that Jasmonate-Zim 1-3 (JAZ 1-3) combined with MYC2-1 inhibited the transcription of gene, while MYC2-1 alone promoted the expression of . The results suggested that a higher concentration of GA is conducive to breaking the dormancy of flower buds and promoting the development of male flower buds, while a lower concentration of GA and a higher concentration of JA-ILE are conducive to the differentiation and formation of female flower buds in post-winter, in which and play a key role in the differentiation of female flower buds of chestnut.
板栗是一种重要的木本粮食作物，但在栽培中产量较低，主要原因是雌花少，雄花多。因此，调控板栗花的转化，有效平衡雌雄比例，提高产量是生产中亟待解决的关键。本研究以冬前和冬后的板栗花芽为材料，通过转录组学和代谢组学分析板栗花芽分化过程中的代谢物、激素和基因表达数据，初步揭示冬前和冬后雌雄花芽转化的可能原因。差异表达基因（DEGs）分析表明，冬前和冬后完全混合花芽（CMF）组有 6323 个 DEGs，其中上调基因 3448 个，下调基因 2875 个。冬前和冬后不完全混合花芽（IMF）有 8037 个 DEGs，其中上调基因 4546 个，下调基因 3491 个。两个花芽的 726 个基因共富集到冬后 251 个京都基因与基因组百科全书（KEGG）通路，其中植物激素信号转导占 4.13%。差异代谢物分析结果表明，两个花芽的差异代谢物主要集中在次生代谢物合成途径。激素含量差异表明，冬前 CMF 中赤霉素 9（GA9）和 GA19 的含量高于 IMF，而冬后则相反。冬前 CMF 中茉莉酸甲酯（MeJA）含量仅很高，而冬后 CMF 中茉莉酰基-（L）-异亮氨酸（JA-ILE）含量较高。冬后，JA-ILE 浓度与花分生组织基因（）表达呈正相关，基因与、和（LEAFY3）的表达水平呈显著正相关。JA-ILE 浓度与基因转录水平呈负相关。体外实验进一步验证了茉莉酸-Zim 1-3（JAZ1-3）与 MYC2-1 结合抑制基因的转录，而 MYC2-1 单独促进基因的表达。结果表明，较高浓度的 GA 有利于打破花芽休眠，促进雄花芽发育，而冬后较低浓度的 GA 和较高浓度的 JA-ILE 有利于雌花的分化和形成，其中和基因在板栗雌花的分化中起关键作用。
