School of Plant Science, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia.
Science. 2011 Feb 4;331(6017):582-5. doi: 10.1126/science.1197985. Epub 2010 Dec 16.
Carbon and water flow between plants and the atmosphere is regulated by the opening and closing of minute stomatal pores in surfaces of leaves. By changing the aperture of stomata, plants regulate water loss and photosynthetic carbon gain in response to many environmental stimuli, but stomatal movements cannot yet be reliably predicted. We found that the complexity that characterizes stomatal control in seed plants is absent in early-diverging vascular plant lineages. Lycophyte and fern stomata are shown to lack key responses to abscisic acid and epidermal cell turgor, making their behavior highly predictable. These results indicate that a fundamental transition from passive to active metabolic control of plant water balance occurred after the divergence of ferns about 360 million years ago.
植物与大气之间的碳和水流动是由叶片表面微小的气孔开闭来调节的。通过改变气孔的孔径，植物可以根据许多环境刺激来调节水分损失和光合作用碳的获取，但目前还无法可靠地预测气孔的运动。我们发现，特征化种子植物气孔控制的复杂性在早期分化的维管植物谱系中缺失。石松类植物和蕨类植物的气孔被证明缺乏对脱落酸和表皮细胞膨压的关键响应，这使得它们的行为具有高度可预测性。这些结果表明，大约 3.6 亿年前蕨类植物分化后，植物水分平衡的代谢控制从被动转变为主动，发生了根本性的转变。
