Central roles for potassium and sucrose in guard-cell osmoregulation
Central roles for potassium and sucrose in guard-cell osmoregulation
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DOI：
10.1104/pp.111.4.1051
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发表时间：
1996-08-01
期刊：
影响因子：
7.4
通讯作者：
Zeiger, E
中科院分区：
文献类型：
--
作者：
Talbott, LD;Zeiger, E
研究了生长箱和温室条件下生长的完整、贴壁蚕豆叶片在气孔运动的日光周期中保卫细胞的渗透调节。在这两种生长条件下，保卫细胞有两个不同的生长调节阶段。在第一阶段（上午），开放与K+吸收，在较小程度上，蔗糖积累。在第二（下午）阶段，在这一时期的光圈最大，K+含量下降，蔗糖成为优势的小麦。重新开放的气孔CO2诱导的关闭后，伴随着K+或蔗糖的积累，这取决于一天中的时间，表明一个单一的环境信号可能会使用多个调节途径。苹果酸的积累，与K+吸收，检测到在生长室，而不是温室条件下，而Cl-是在温室中的主要K+ counterparts。这些结果表明，在完整的叶片保卫细胞的光合调节依赖于至少两个不同的光合调节途径，K+运输和蔗糖代谢。此外，K+抗衡离子苹果酸盐和Cl-的相对重要性似乎是环境依赖的。
Osmoregulation in guard cells of intact, attached Vicia faba leaves grown under growth chamber and greenhouse conditions was studied over a daily light cycle of stomatal movements. Under both growth conditions guard cells had two distinct osmoregulatory phases. In the first (morning) phase, opening was correlated with K+ uptake and, to a lesser extent, sucrose accumulation. In the second (afternoon) phase, in which apertures were maximal, K+ content declined and sucrose became the dominant osmoticum. Reopening of the stomata after a CO2-induced closure was accompanied by accumulation of either K+ or sucrose, depending on the time of day, indicating that a single environmental signal may use multiple osmoregulatory pathways. Malate accumulation, correlated with K+ uptake, was detected under growth chamber but not greenhouse conditions, whereas Cl- was the main K+ counterion in the greenhouse. These results indicate that guard-cell osmoregulation in the intact leaf depends on at least two different osmoregulatory pathways, K+ transport and sucrose metabolism. Furthermore, the relative importance of the K+ counterions malate and Cl- appears to be environment-dependent.