沙棘果实发育过程中内源激素水平的动态变化

沙棘(Hippophae rhamnoides)是荒漠化防治和水土保持的重要经济树种, 其果实中含有丰富的生物活性成分。内源激素生长素(IAA)、赤霉素(GA₄)、脱落酸(ABA)和茉莉酸(JA)在沙棘果实发育过程中起着重要的调控作用, 但不同发育期内源激素的动态变化及其对果实生长发育的影响仍不清楚。以亲缘关系近且含油量差异明显的2个沙棘品系不同发育期果实为材料, 利用液相色谱串联质谱法检测了4种内源激素含量的动态变化。结果表明, 在果实发育过程中, 80%–85%的含水量有利于内源激素浓度的相对稳定; 果实含油量在不同发育期增速基本一致, 2个品系含油量在中后期开始出现明显差异。IAA和JA含量在果实成熟过程中呈先高后低的趋势; ABA含量在果实发育中后期始终处于较高水平; 而GA₄含量一直处于较低水平。高ABA/GA₄有利于果实油脂的合成与积累。研究结果为揭示不同内源激素对沙棘果实发育的调节作用提供了理论依据。

Dynamic Changes of Hormones Contents in Different Fruit Developmental Stages of Sea Buckthorn

Sea buckthorn (Hippophae rhamnoides) is an economically important tree that grows well under dry and unfertileconditions and has berries with valuable bioactive compounds. Plant endogenous hormones (i.e., indole-3-aceticacid (IAA), gibberellin (GA₄), abscisic acid (ABA), and jasmonic acid (JA)) play an important role in regulating the growthand development of fruits. However, the dynamic contents changes of these hormones during fruit development in seabuckthorn have not yet been determined. In this study, we investigated two closely related sea buckthorn accessions withwidely different oil contents. Fruits were harvested at different developmental stages of the two accessions on July 1, July17, August 2, and August 18, and contents of four endogenous hormones (IAA, GA₄, ABA, and JA) were analyzed by highperformance liquid chromatography-mass spectrum (LC-MS). The moisture contents in berries remained about 80%–85%throughout fruit development, which were beneficial to the relative stability of endogenous hormone concentration. Thegrowth rates of oil contents were basically the same during different development stages. By contrast, oil contents beganto differ between the two accessions during the middle and late periods of fruit development. Concentrations of IAA andJA were relatively high in the beginning, then decreased toward the end of fruit ripening. The concentration of ABA wasrelatively high in the middle and late stages of fruit development, whereas concentration of GA₄ was much lower; a highratio of ABA to GA₄ was advantageous to oil biosynthesis and accumulation in the fruits. The results provide a theoreticalbasis for understanding the regulation of different endogenous hormones in sea buckthorn fruit development.