Blue light-modulation of chlorophyll a fluorescence transients in guard cell chloroplasts.
Blue light-modulation of chlorophyll a fluorescence transients in guard cell chloroplasts.
复制标题
叶绿素的蓝光调制，保卫细胞叶绿体中的荧光瞬变。
DOI：
10.1104/pp.96.3.753
复制
发表时间：
1991
期刊：
影响因子：
7.4
通讯作者：
E. Zeiger
中科院分区：
文献类型：
--
作者：
B. Mawson;E. Zeiger
用显微荧光光谱法测定了蚕豆叶肉和单个保卫细胞对的叶绿素a荧光瞬变。在两种叶绿体类型中，光化蓝光和绿色光下的荧光诱导（O到P）相似。在缓慢的瞬变从叶肉细胞叶绿体，蓝色和绿色光诱导相同的，典型的快速淬火从P到S，和M峰。与此相反，从保卫细胞（GC）叶绿体的P到S的瞬态与蓝光照射表现出慢得多的猝灭速率，P到T的转换没有显示M峰。光化绿色光在GC叶绿体中诱导了类似叶肉的瞬变，包括从P到S的快速淬灭和M峰。在单对GC和分离的原生质体中检测这些瞬变排除了叶肉污染作为信号源。绿色光在几种植物的GC叶绿体中诱导了一个快速猝灭和M峰。在pH 6.8和10.0的条件下，研究了HCO（3）（-）存在下CO（2）浓度对荧光瞬变的影响。在由绿色光诱导的两种叶绿体类型的瞬态中，pH值的增加伴随着CO（2）浓度的降低引起猝灭的初始速率的增加和M峰的消除。光化蓝光诱导的叶肉样瞬变GC叶绿体在10微摩尔KCN的存在下，在该浓度下，蓝光诱导的气孔开放被抑制。添加100至200微摩尔磷酸盐也引起荧光猝灭速率和M峰的大幅增加。这些结果表明，蓝光调节GC叶绿体的光合活性。在不存在与蓝光响应相关的转导事件且存在高磷酸盐浓度的情况下，不会观察到这种蓝光效应。
Chlorophyll a fluorescence transients from mesophyll and single guard cell pairs of Vicia faba were measured by microspectrofluorometry. In both chloroplast types, fluorescence induction (O to P) was similar under actinic blue and green light. In slow transients from mesophyll cell chloroplasts, blue and green light induced identical, typical rapid quenching from P to S, and the M peak. In contrast, the P to S transient from guard cell (GC) chloroplasts irradiated with blue light showed a much slower quenching rate, and the P to T transition showed no M peak. Actinic green light induced mesophyll-like transients in GC chloroplasts, including rapid quenching from P to S and the M peak. Detection of these transients in single pairs of GC and isolated protoplasts ruled out mesophyll contamination as a signal source. Green light induced a rapid quenching and the M peak in GC chloroplasts from several species. The effect of CO(2) concentration on the fluorescence transients was investigated in the presence of HCO(3) (-) at pH 6.8 and 10.0. In transients induced by green light in both chloroplast types, a pH increase concomitant with a reduction in CO(2) concentration caused an increase in the initial rate of quenching and the elimination of the M peak. Actinic blue light induced mesophyll-like transients from GC chloroplasts in the presence of 10 micromolar KCN, a concentration at which the blue light-induced stomatal opening is inhibited. Addition of 100 to 200 micromolar phosphate also caused large increases in fluorescence quenching rates and a M peak. These results indicate that blue light modulates photosynthetic activity in GC chloroplasts. This blue light effect is not observed in the absence of transduction events connected with the blue light response and in the presence of high phosphate concentrations.