Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, 04510 Ciudad de México (CDMX), Mexico;
Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, 04510 Ciudad de México (CDMX), Mexico.
Proc Natl Acad Sci U S A. 2018 Jul 17;115(29):7551-7556. doi: 10.1073/pnas.1721728115. Epub 2018 Jul 2.
Understanding how plants survive drought and cold is increasingly important as plants worldwide experience dieback with drought in moist places and grow taller with warming in cold ones. Crucial in plant climate adaptation are the diameters of water-transporting conduits. Sampling 537 species across climate zones dominated by angiosperms, we find that plant size is unambiguously the main driver of conduit diameter variation. And because taller plants have wider conduits, and wider conduits within species are more vulnerable to conduction-blocking embolisms, taller conspecifics should be more vulnerable than shorter ones, a prediction we confirm with a plantation experiment. As a result, maximum plant size should be short under drought and cold, which cause embolism, or increase if these pressures relax. That conduit diameter and embolism vulnerability are inseparably related to plant size helps explain why factors that interact with conduit diameter, such as drought or warming, are altering plant heights worldwide.
随着世界各地的植物在潮湿地区因干旱而枯萎，在寒冷地区因变暖而生长得更高，了解植物如何在干旱和寒冷中生存变得越来越重要。在植物的气候适应中，至关重要的是输水管道的直径。我们对 537 个种进行了采样，这些种分布在以被子植物为主的气候带中，发现植物大小是输水管道直径变化的主要驱动因素。而且，由于较高的植物具有较宽的导管，而同一物种内较宽的导管更容易受到导阻栓塞的影响，因此较高的同种植物应该比较矮的同种植物更容易受到影响，我们用种植园实验证实了这一预测。因此，在干旱和寒冷导致栓塞的情况下，最大植物大小应该很短，如果这些压力得到缓解，最大植物大小应该增加。输水管道直径和栓塞脆弱性与植物大小密不可分，这有助于解释为什么与输水管道直径相互作用的因素，如干旱或变暖，正在改变全球植物的高度。
