It's all about timing—or is it? Exploring the potential connection between phloem physiology and whole plant phenology
It's all about timing—or is it? Exploring the potential connection between phloem physiology and whole plant phenology
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一切都与时机有关——是吗？
DOI：
10.1002/ajb2.1480
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发表时间：
2020
影响因子：
3
通讯作者：
Savage, Jessica A.
中科院分区：
文献类型：
--
作者：
Savage, Jessica A.
从发芽到叶片衰老的物候过程以器官生长的变化和维管系统资源的调动为特征。然而，在季节性寒冷的气候中，许多重要的物候事件（物候期）发生在春季和秋季，此时维持活跃的维管系统是危险的，木质部和韧皮部的运输可能会受到损害。了解这些关键时期植物的生长和营养物质的再动员需要对维管物候学的理解。虽然有少数研究表明木质部解剖/生理与叶物质性之间存在跨物种的联系（Lechowicz, 1984； Wang等，1992；Panchen等，2014;Fahey, 2016），但关于韧皮部的研究很少，而且它们只关注少数物种（Prislan等，2013；lavrije等，2017;montw<s:1>等，2019）。考虑到韧皮部在运输营养物质、资源和调节器官生长和分配的远程信号方面的关键作用，在文献中对韧皮部的代表性不足令人惊讶（回顾，见Ham和Lucas， 2014）。在这里，我认为研究韧皮部的季节变化对于理解植物物候学的生理限制是必要的，并提出了韧皮部影响木本落叶被子植物叶片和花朵物候学的两种可能方式，一种是在春季，一种是在秋季。
Phenological events from budburst to leaf senescence are characterized by changes in organ growth and the mobilization of resources in the vascular system. Yet, in seasonally cold climates, many important phenological events (phenophases) occur in the spring and autumn at times when maintaining an active vascular system is risky and transport in the xylem and phloem might be compromised. Understanding plant growth and nutrient remobilization at these critical times requires a comprehension of vascular phenology. Although a handful of studies have shown links between xylem anatomy/physiology and leaf phenology across species (Lechowicz, 1984; Wang et al., 1992; Panchen et al., 2014; Fahey, 2016), few studies exist on the phloem, and they focus on a small set of species (Prislan et al., 2013; Lavrič et al., 2017; Montwé et al., 2019). This underrepresentation of phloem in the literature is surprising considering the phloem’s critical role in transporting nutrients, resources, and long-distance signals important in regulating organ growth and allocation (for review, see Ham and Lucas, 2014). Here, I make the case that studying seasonal changes in the phloem is necessary for understanding physiological limits to plant phenology and propose two potential ways that the phloem could influence leaf and flower phenology in woody, deciduous angiosperms, one in the spring and one in the autumn.