Abstract：
Perennial trees have a recurring annual cycle of wood formation in response to environmental fluctuations. However, the precise molecular mechanisms that regulate the seasonal formation of wood remain poorly understood. Our prior study indicates that VCM1 and VCM2 play a vital role in regulating the activity of the vascular cambium by controlling the auxin homoeostasis of the cambium zone in Populus. This study indicates that abscisic acid (ABA) affects the expression of VCM1 and VCM2, which display seasonal fluctuations in relation to photoperiod changes. ABA-responsive transcription factors AREB4 and AREB13, which are predominantly expressed in stem secondary vascular tissue, bind to VCM1 and VCM2 promoters to induce their expression. Seasonal changes in the photoperiod affect the ABA amount, which is linked to auxin-regulated cambium activity via the functions of VCM1 and VCM2. Thus, the study reveals that AREB4/AREB13-VCM1/VCM2-PIN5b acts as a molecular module connecting ABA and auxin signals to control vascular cambium activity in seasonal wood formation.
摘要：
多年生树木因环境波动而反复出现木材形成的年度循环。然而,调节木材季节性形成的精确分子机制仍然知之甚少。我们先前的研究表明，VCM1和VCM2通过控制杨树形成层区的生长素稳态，在调节维管形成层的活性中起着至关重要的作用。这项研究表明，脱落酸（ABA）影响VCM1和VCM2的表达，这显示出与光周期变化有关的季节性波动。ABA反应性转录因子AREB4和AREB13主要在茎次级血管组织中表达，结合VCM1和VCM2启动子以诱导它们的表达。光周期的季节性变化会影响ABA的数量，通过VCM1和VCM2的功能与生长素调节的形成层活性有关。因此，该研究表明，AREB4/AREB13-VCM1/VCM2-PIN5b充当连接ABA和生长素信号的分子模块，以控制季节性木材形成中的维管形成层活性。
