Light Intensity Affects Ozone-Induced Stomatal Sluggishness in Snapbean
详细信息 查看全文
- 作者：Yasutomo Hoshika ; Alessandra De Marco ; Alessandro Materassi…
- 关键词：Tropospheric ozone ; Stomatal response ; Stomatal conductance ; Stomatal sluggishness ; Snapbean
- 刊名：Water, Air, and Soil Pollution
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：227
- 期：11
- 全文大小：595 KB
- 刊物类别：Earth and Environmental Science
- 刊物主题：Environment
Environment
Atmospheric Protection, Air Quality Control and Air Pollution
Waste Water Technology, Water Pollution Control, Water Management and Aquatic Pollution
Terrestrial Pollution
Hydrogeology - 出版者：Springer Netherlands
- ISSN：1573-2932
- 卷排序：227
文摘
Tropospheric ozone (O3) is the air pollutant of most concern to vegetation at present. Ozone impacts on stomata are still controversial, as both decreased stomatal conductance and slow stomatal responses to environmental stimuli (namely, stomatal sluggishness) have been shown. We postulated that the light environment affects stomatal sluggishness. To concurrently manipulate O3 and light conditions and measure gas exchange at leaf level, we developed an innovative O3 exposure system by modifying a commercially available gas exchange system. We exposed the first trifoliate leaf of the O3-sensitive genotype S156 of snapbean (Phaseolus vulgaris) to a 1-h O3 exposure (150 ppb) under 1000 μmol m−2 s−1 photosynthetic photon flux density, so that stomata were fully open and O3 uptake was maximized. Then, leaves were subjected to different light intensities (200, 1000, or 1500 μmol m−2 s−1) until a steady state was reached. As a metric of sluggishness, we quantified the stomatal responses to a sharp water stress generated by cutting the petiole at steady state. The results showed that O3 exposure induced stomatal sluggishness only under high light (stomata needed 53 % more time to half stomatal conductance relative to steady state) and did not when the plants were under lower light intensities. We conclude that O3-induced stomatal sluggishness may occur only in fully irradiated leaves, and suggest it is a minor response when entire crowns and canopies are assessed and a major reason of the higher O3 sensitivity of sun leaves than of shade leaves.