Plant Developmental Genetics, Institute of Biology Leiden, Leiden University, Leiden, the Netherlands.
Institute of Biotechnology and Genetic Engineering, University of Agriculture Peshawar, Peshawar, Pakistan.
Nat Plants. 2020 Apr;6(4):368-376. doi: 10.1038/s41477-020-0637-z. Epub 2020 Apr 13.
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.
植物的胚胎后发育和长寿在很大程度上取决于在叶片腋处形成的干细胞巢（即所谓的腋芽分生组织（AMs））的活性和成熟状态。与 AM 成熟相关并构成单性结实（一次性繁殖和死亡）一年生植物与寿命更长的多性结实（多次繁殖）多年生植物之间差异基础的基因在很大程度上仍然未知。在这里，我们确定了拟南芥 AT-HOOK MOTIF NUCLEAR LOCALIZED 15（AHL15）基因的一个新作用，作为 AM 成熟的抑制剂。AHL15 功能的丧失会加速 AM 的成熟，而 AHL15 的异位表达则会抑制 AM 的成熟，并促进单性结实的拟南芥和烟草的长寿。因此，在促进长寿的短日照条件下生长的拟南芥或多性结实的拟南芥 lyrata 中，AHL15 在 AM 中上调表达。总之，我们的结果表明，AHL15 和其他 AHL 家族-A 基因在抑制 AM 成熟和延长植物寿命方面发挥着重要作用，它们直接位于开花基因（SOC1、FUL）下游，位于促进开花的激素赤霉素的上游。
