Avoiding high relative air humidity during critical stages of leaf ontogeny is decisive for stomatal functioning
Avoiding high relative air humidity during critical stages of leaf ontogeny is decisive for stomatal functioning
复制标题
DOI：
10.1111/j.1399-3054.2011.01475.x
复制
发表时间：
2011-07-01
影响因子：
6.4
通讯作者：
Heuvelink, Ep
中科院分区：
文献类型：
--
作者：
Fanourakis, Dimitrios;Carvalho, Susana M. P.;Heuvelink, Ep
一些物种的植物，如果在高相对空气湿度（RH >= 85%）下生长，在叶水势低的情况下，会形成无法完全关闭的气孔。我们研究了在中度（60%）或高度（95%）相对湿度下生长的蔷薇在叶片展开的不同阶段，相对湿度的相互变化对气孔关闭能力的影响。这是通过测量叶子完全展开后对干燥的响应的叶子蒸腾速率来评估的。对于在高相对湿度下开始扩展但在转移到中等相对湿度后完成扩展的叶子，这种转换发生得越早，气孔功能就越好。叶子最初在中等相对湿度下扩展，然后转移到高相对湿度，表现出较差的气孔功能，即使这种转移在叶子扩展过程中发生得很晚。如果在全叶展开 (FLE) 之前进行，每天向在持续高相对湿度下生长的植物的叶子施用脱落酸 (ABA) 溶液，可有效诱导低水势下的气孔关闭。 FLE 后，气孔功能不再受 RH 或 ABA 水平的影响。结果表明，气孔适应的程度取决于暴露于高相对湿度的时间和持续时间。结论是，气孔功能很大程度上取决于叶子完成扩张时的湿度。数据还表明，环境相对湿度的影响和ABA的缓解作用仅限于叶片展开时期。
Plants of several species, if grown at high relative air humidity (RH >= 85%), develop stomata that fail to close fully in case of low leaf water potential. We studied the effect of a reciprocal change in RH, at different stages of leaf expansion of Rosa hybrida grown at moderate (60%) or high (95%) RH, on the stomatal closing ability. This was assessed by measuring the leaf transpiration rate in response to desiccation once the leaves had fully expanded. For leaves that started expanding at high RH but completed their expansion after transfer to moderate RH, the earlier this switch took place the better the stomatal functioning. Leaves initially expanding at moderate RH and transferred to high RH exhibited poor stomatal functioning, even when this transfer occurred very late during leaf expansion. Applying a daily abscisic acid (ABA) solution to the leaves of plants grown at continuous high RH was effective in inducing stomatal closure at low water potential, if done before full leaf expansion (FLE). After FLE, stomatal functioning was no longer affected either by the RH or ABA level. The results indicate that the degree of stomatal adaptation depends on both the timing and duration of exposure to high RH. It is concluded that stomatal functionality is strongly dependent on the humidity at which the leaf completed its expansion. The data also show that the effect of ambient RH and the alleviating role of ABA are restricted to the period of leaf expansion.