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Nature Plants：腋生分生组织成熟抑制因子促进开花植物长寿

已有 4560 次阅读 2020-4-15 08:10 |个人分类:每日摘要|系统分类:论文交流

A suppressor of axillary meristem maturation promotes longevity in flowering plants

First author: Omid Karami; Affiliations: Leiden University (莱顿大学): Leiden, the Netherlands

Corresponding author: Remko Offringa

Post-embryonic development and longevity of flowering plants are, for a large part, determined by the activity and maturation state of stem cell niches formed in the axils of leaves, the so-called axillary meristems (AMs). The genes that are associated with AM maturation and underlie the differences between monocarpic (reproduce once and die) annual and the longer-lived polycarpic (reproduce more than once) perennial plants are still largely unknown. Here we identify a new role for the Arabidopsis AT-HOOK MOTIF NUCLEAR LOCALIZED 15 (AHL15) gene as a suppressor of AM maturation. Loss of AHL15 function accelerates AM maturation, whereas ectopic expression of AHL15 suppresses AM maturation and promotes longevity in monocarpic Arabidopsis and tobacco. Accordingly, in Arabidopsis grown under longevity-promoting short-day conditions, or in polycarpic Arabidopsis lyrata, expression of AHL15 is upregulated in AMs. Together, our results indicate that AHL15 and other AHL clade-A genes play an important role, directly downstream of flowering genes (SOC1, FUL) and upstream of the flowering-promoting hormone gibberellic acid, in suppressing AM maturation and extending the plant’s lifespan.

有花植物胚后发育和长寿很大程度上由叶腋处的干细胞龛，即腋生分生组织的活性和成熟状态所决定。然而，与腋生分生组织成熟相关基因以及结一次果的一年生植物和多次结果的多年生植物之间差异背后的相关基因还不清楚。本文中，作者鉴定到了拟南芥AHL15基因的一个新功能，作为腋生分生组织成熟的抑制因子。AHL15基因的功能缺失突变会加速腋生分生组织的成熟，而异位表达AHL15基因则会抑制腋生分生组织的成熟，并促进一年生植物烟草和拟南芥的长寿。与此一致的是，当拟南芥处于促进长寿的短日照条件下生长时，或是在多年生琴叶拟南芥中，AHL15基因在腋生分生组织中的表达量都会上调。综上，本文的研究结果揭示了AHL15基因和AHL的A类基因在开花基因（SOC1, FUL）的下游和促进开花的植物激素赤霉素上游发挥功能，作用于腋生分生组织成熟的抑制和植物寿命的延长。