赤霉素代谢与信号转导及其调控种子萌发与休眠的分子机制

Gibberellin metabolism and signaling and its molecular mechanism in regulating seed germination and dormancy

种子的萌发能力由胚周围组织(种皮和胚乳)强加的物理限制与胚的生长潜能之间的平衡所决定.覆盖胚根尖端的珠孔端胚乳细胞的弱化被植物激素赤霉素(gibberellin,GA)促进但被脱落酸抑制,是胚根伸出的重要前提.GA是一种调控植物许多关键生理过程,如种子萌发、根和茎的伸长、开花、座果和种子发育的重要激素.GA在种子萌发与休眠解除中的作用主要受其生物合成与分解代谢和信号转导途径的调控.本文主要综述了GA的生物合成与代谢、GA的信号转导以及它们对种子萌发和休眠解除调控的研究进展.此外,本文也提出了本领域需要进一步研究的科学问题,试图为解释GA调控种子萌发与休眠的分子机理提供新的研究信息.

The ability of seeds to germinate is determined by a balance between the physical restriction imposed by the embryo-surrounding tissues,i.e.,testa and endosperm,and the potential of the embryo to grow.The weakening of the micropylar endosperm cells covering the radicle tip is promoted by phytohormone gibberellin(GA)but inhibited by abscisic acid,which is an important prerequisite for radicle protrusion.GA is a major phytohormone regulating various key physiological processes in plants such as seed germination,root and shoot elongation,flowering,fruiting,and seed development.The role of GA in seed germination and dormancy release is mainly regulated by its biosynthesis and catabolism as well as signaling pathways.Herein,we mainly summarize the research progresses of GA biosynthesis and catabolism,signaling,and their regulation on seed germination and dormancy release.In addition,we propose some scientific issues required for further investigations in this field to provide a research clue for understanding the molecular mechanisms of seed germination and dormancy that are regulated by GA.