蓝光诱导气孔开放. 生物科学与技术学院 王慧慧 2007 年 5 月. 光是控制气孔运动的最主要环境信号，通常气孔在光下开放，暗中关闭。 用光合电子传递的抑制剂 DCMU 处理叶片， 只能部分抑制气孔在光下开放 。这表明气孔开放除保卫细胞叶绿体的 光合作用 外还有其他反应参与。. 在双光实验中，首先用红光饱和保卫细胞叶绿体的光合作用，在红光照射使气孔开度达定值时如果再给予蓝光照射，会进一步引起气孔开度明显增加。. 图 红光背景下气孔对蓝光的反应 用饱和的红光照射鸭跖草的离体表皮，在气孔开度达定值时给於蓝光照射，会使气孔孔径明显增加。
(Schwartz & Zeiger1984)
(Shimazaki et al.1986)
(Toshinori Kinoshita, Nature,2001)
(E) Confocal images of stomata of the WT, cry1, cry2, cry1 cry2, CRY1-ovx, and CRY2-ovx plants. Epidermal strips were illuminated with 5molm2s1 blue light under background 50molm2s1 red light for 3 h. (F) Stomatal apertures under different light conditions in the WT, cry1, cry2, cry1 cry2, CRY1-ovx, and CRY2-ovx plants. Stomatal opening was induced by 50 molm2s1 red light and 20 molm2s1 blue light plus 50 molm2s1 red light. Stomata of the WT plants open significantly wider than those of the cry1 single and cry1 cry2 double mutant under 20 molm2s1 blue light plus 50 molm2s1 red light respectively. (G) Fluence rate dependency of stomatal opening in response to blue light. The measurements represent stomatal apertures obtained at different fluence rates of blue light under background 50 molm2s1 red light.
(A) ()(B) (Karlsson 1986)
(Srivastava & Zeiger,1995)
npq1 (nonphotochemical quenching)npq1
14-3-3 proteins are conserved phosphopeptide-binding proteins. 14-3-3 proteins exist as dimers, with each monomer able to bind a target peptide sequence within the groove created on the conserved inner face of the protein. Shown here are (a) side and (b) front views of a molecular model of a human 14-3-3z monomer with a bound phosphopeptide shown in black .
Generic function of 14-3-3 proteins. Proteins phosphorylated on serine residues within specific motifs become targets for 14-3-3 binding. Interaction can result in an altered behaviour of the target protein through one of a range of different mechanisms that are summarised in the figure.
Fig. Stomata opening of the cop1 mutant, GUS-CCT1, and GUS-CCT2 plants in darkness and under different light conditions. (A) Confocal images showing that stomata of the cop1-4 mutant, GUS-CCT1, and GUS-CCT2 plants are constitutively open in darkness, and open wider than those of the WTunder 50 molm2s1 red, 50 molm2s1 far-red, and 5 molm2s1 blue light plus 50 molm2s1 red light. (B) Stomatal apertures in the cop1 mutant, GUS-CCT1, and GUS-CCT2 plants under the same conditions in A.
Signaling pathways illustrating coactions of CRY and PHOT in the regulation of stomatal opening presumably through negative regulation of COP1. Solid line indicates the defined direct CRYCOP1 interaction ,and the dashed line denotes the presumptive interactions. X, postulated intermediate signaling partner(s) actingbetween phototropins andCOP1.
Light Regulation of Stomatal Movement. Annu. Rev. Plant Biol. 2007. 58:21947
Figure 1 Green light reversal of blue light-stimulated opening in continuous light experiments. Stomata were illuminated with 10 mol m2s1 blue light given alone or together with green light of 10 or 20 mol m2s1. Results are shown as the percent reduction of the opening stimulated by blue light. The inset shows the average final aperturevalues. Data after Frechilla et al., 2000.
Figure 2 Action spectrum for the inhibition of blue light-stimulated stomatal opening by green light in Vicia faba. Inhibition curves similar to that shown in Figure 1 were obtained for each wavelength and the action spectrum was obtained by calculating the fluence rate of light at that wavelength necessary to obtain 50% inhibition (green curve). Data after Frechilla et al., 2000. The action spectrum for blue light-stimulated opening (blue curve) is shown for comparison (Karlsson, 1986).