Conservation and diversification of HAIRY MERISTEM gene family in land plants
Conservation and diversification of HAIRY MERISTEM gene family in land plants
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DOI：
10.1111/tpj.15169
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发表时间：
2021-03-27
期刊：
影响因子：
7.2
通讯作者：
Zhou, Yun
中科院分区：
文献类型：
--
作者：
Geng, Yuan;Guo, Lei;Zhou, Yun
陆地植物茎尖分生组织对植物的生长和器官的形成至关重要。在一些被子植物中，毛分生组织（HAM）基因作为控制分生组织发育和干细胞稳态的关键调节因子发挥作用。迄今为止，HAM家族在陆地植物中的起源和进化历史仍不清楚。来自被子植物和非被子植物的HAM家族成员的潜在共享和分歧功能也不清楚。在构建一个全面的同源性的HAM家族，我们表明，HAM蛋白广泛存在于陆地植物和HAM蛋白起源之前的分歧brabrites。HAM家族在被子植物的共同祖先中复制，导致两个不同的组：I型和II型。II型HAM成员广泛存在于被子植物中，而I型HAM成员在单子叶植物的不同目中独立丢失。此外，来自被子植物和非被子植物（包括苔藓植物、石松植物、蕨类植物和裸子植物）的HAM成员能够取代拟南芥中II型HAM基因的作用，维持已建立的SAM并促进新的干细胞小生境的启动。我们的研究结果揭示了HAM家族成员的保守功能，并揭示了HAM分生组织表达模式的保守调控机制，为陆地植物关键干细胞调控因子的进化提供了见解。
The shoot apical meristems (SAMs) of land plants are crucial for plant growth and organ formation. In several angiosperms, the HAIRY MERISTEM (HAM) genes function as key regulators that control meristem development and stem cell homeostasis. To date, the origin and evolutionary history of the HAM family in land plants remains unclear. Potentially shared and divergent functions of HAM family members from angiosperms and non-angiosperms are also not known. In constructing a comprehensive phylogeny of the HAM family, we show that HAM proteins are widely present in land plants and that HAM proteins originated prior to the divergence of bryophytes. The HAM family was duplicated in a common ancestor of angiosperms, leading to two distinct groups: type I and type II. Type-II HAM members are widely present in angiosperms, whereas type-I HAM members were independently lost in different orders of monocots. Furthermore, HAM members from angiosperms and non-angiosperms (including bryophytes, lycophytes, ferns and gymnosperms) are able to replace the role of the type-II HAM genes in Arabidopsis, maintaining established SAMs and promoting the initiation of new stem cell niches. Our results uncover the conserved functions of HAM family members and reveal the conserved regulatory mechanisms underlying HAM expression patterning in meristems, providing insight into the evolution of key stem cell regulators in land plants.