油茶花芽分化后期内源激素与代谢组学差异分析

Difference analysis of endogenous hormones and metabolomics in the late stage of flower buds differentiation of Camellia oleifera

【目的】解析内源激素和关键代谢物调控油茶花芽分化的分子机制。【方法】以3个分化时期(雌雄蕊形成期、子房和花药形成期、雌雄蕊成熟期)的普通油茶花芽为研究对象,采用LC-MS和GC-MS技术分别进行内源激素和代谢物差异分析,并对差异代谢物进行PCA主成分分析和OPLS-DA分析,研究不同激素在3个分化时期的动态变化,解析关键代谢物所参与的代谢通路。【结果】从雌雄蕊形成期到雌雄蕊成熟期,GA、MEJA、ME-IAA等9种激素含量呈先增加后减少的趋势,ABA含量呈先降后升的趋势,IAA、ICAld、SA、t Z含量呈一直下降的趋势,IP含量一直上升。同时,与雌雄蕊形成期相比,在子房和花药形成期的油茶花芽中共检测到519种代谢物,其中差异代谢物有95种(72种上调,23种下调),在雌雄蕊成熟期的油茶花芽中共检测到520种代谢物,其中差异代谢物有135种(80种上调,55种下调)。【结论】在油茶花芽分化后期,高含量的GA在子房和花药形成期起到较大作用;较低含量的IAA和较高含量的ABA可能对雌雄蕊成熟期有促进作用,可能促进油茶花芽成熟和开花;赤霉素和酚酸含量增加,促进氨基酸合成为可溶性蛋白;细胞分裂素含量上升可能与促进黄酮类化合物的生成有关。黄酮类化合物和酚酸的含量在这3个时期呈持续升高的趋势,说明这2类物质在油茶花芽分化后期对花芽分化有一定的促进作用。

【Objective】To analyze the molecular mechanism of endogenous hormones and significant metabolites regulating the buds differentiation of Camellia oleifera.【Method】The flower buds of C.oleifera in three stages of differentiation(stamen and pistil formation,ovary and anther formation,stamen and pistil maturity)were studied.Endogenous hormones and different metabolites of C.oleifera during these stages were analyzed by LC-MS and GC-MS,respectively.PCA,OPLS-DA were performed to the differential metabolites.Meanwhile,we analyzed dynamic changes of different endogenous hormones in the three stages of buds differentiation,and resolved the metabolic pathway in which the significant metabolites involved.【Result】From stamen and pistil formation to stamen and pistil maturity,the content of GA,MEJA,ME-IAA and other 9 hormones decreased after increased,ABA content increased after decreased,the content of IAA,ICAld,SA and tZ kept going down,the content of IP kept going up;simultaneously,compared to stamen and pistil formation,95 metabolites(72 metabolites up regulated and 23 metabolites down regulated)were selected from 519 metabolites detected from anther and ovule formation,135 metabolites(80 metabolites up regulated and 55 metabolites down regulated)were selected from 520 metabolites detected from stamen and pistil maturity.【Conclusion】At the late stages of buds differentiation,high content of GA plays a significant role in ovary and anther formation.At the meantime,the low ratio of IAA/ABA may have a promoting effect on stamen and pistil maturity which could facilitate the buds maturation and blooming.The increasing content of GA and phenolic acids could promote the synthesis of amino acids into soluble proteins.The increasing content of cytokinin maybe correlated to the increased flavonoids compounds.The concentration of flavonoids and phenolic acids kept going up,which indicates that these two kinds of substances have a promoting effect to the late stages of flower buds differentiation of C.oleifera.