Control of cambium initiation and activity in Arabidopsis by the transcriptional regulator AHL15

第一作者：Arezoo Rahimi

第一单位：莱顿大学

通讯作者：Remko Offringa

 Abstarct 

背景回顾：Plant secondary growth, which is the basis of wood formation, includes the production of secondary xylem, which is derived from meristematic cambium cells embedded in vascular tissue. 

植物的次生生长是木材形成的基础，包括了次生木质部的形成，而次生木质部则来源于维管组织中具有分生能力的形成层。

主要研究：Here, we identified an important role for the Arabidopsis thaliana (Arabidopsis) AT-HOOK MOTIF CONTAINING NUCLEAR LOCALIZED 15 (AHL15) transcriptional regulator in controlling vascular cambium activity. 

本文中，作者鉴定了拟南芥AHL15转录调控子在控制维管形成层活性方面的重要作用。

结果1-AHL5敲除和过表达：The limited secondary xylem development in inflorescence stems of herbaceous Arabidopsis plants was significantly reduced in ahl15 loss-of-function mutants, whereas constitutive or vascular meristem-specific AHL15 overexpression produced woody inflorescence stems. 

草本植物拟南芥的花序茎次生木质部发育受到限制，在ahl15功能缺失突变体中次生木质部发育进一步受限，但组成型过表达或者维管分生组织特异性过表达AHL15基因会导致花序茎木质化。

结果2-AHL15作用于SOC1和FUL下游：AHL15 was required for enhanced secondary xylem formation in the woody suppressor of overexpression of constans 1 (soc1) fruitfull (ful) double loss-of-function mutant. Moreover, we found that AHL15 induces vascular cambium activity downstream of the repressing SOC1 and FUL transcription factors, most likely similar to how it enhances lateral branching by promoting biosynthesis of the hormone cytokinin. 

AHL15基因是soc1 ful双突植株中次生木质部形成增强所必需的。此外，作者发现AHL15作用于SOC1和FUL转录因子的下游，诱导维管形成层活性，很有可能与其通过促进细胞分裂素生物合成介导侧生分枝的方式类似。

结论：Our results uncover a novel pathway driving cambium development, in which AHL15 expression levels act in parallel to and are dependent on the well-established TDIF-PXY-WOX pathway to differentiate between herbaceous and woody stem growth.

本文的研究结果揭示了一个驱动形成层发育的新途径，其中AHL15基因的表达水平平行且独立于TDIF-PXY-WOX途径，从而介导草本和木本茎的分化。

** Remko Offringa **

doi: https://doi.org/10.1016/j.cub.2022.02.060

Journal: Current Biology

Published date:  March 15, 2022