Different stomatal responses of maize leaves after blue or red illumination under anoxia

Abstract

In normal air, illumination with a low level of blue or red light (40 μmol m−2 s−1) did not induce stomatal opening in maize plantlets. In CO2‐free air, 40 μmol m−2 s−1 of blue or red light promoted an enhancement in stomatal opening. At the same quantum flux, blue light was more efficient than red light and stomatal closure occurred more rapidly with a significantly shorter lag phase after blue light. Anoxia inhibited light‐dependent stomatal opening, even under 320 μmol m−2 s−1 illumination. However, after 60 min of illumination with 40 μmol m−2 s−1 of blue light in anoxia, transient stomatal opening was observed when the plant was returned to darkness and normal air. This transient stomatal opening was weaker after pretreatment with red light. We conclude that a blue‐light‐dependent process induced under anoxia leads to stomatal opening provided oxygen is present. Possible mechanisms associated with blue‐light‐effect and the nature of the oxygen‐consuming processes are discussed.

Regulation of blue-light-induced proton pumping by Vicia faba L. guard-cell protoplasts: Energetic contributions by chloroplastic and mitochondrial activities

“…It is important to note that the response by proton-pumping activity to oxygen levels is coincident with similar reductions in both photosynthetic and respiratory activities by GCPs exposed to the same oxygen concentrations (Mawson 1993). Thus, oxygen-dependency of proton pumping by GCPs shown here and for stomatal opening in intact tissue (Vavasseur et al 1990) possibly reflects the requirement for photo-and oxidative phosphorylation in order to support proton extrusion via a plasmalemma protonATPase. The sensitivity of BL-induced swelling to vanadate by V. faba GCPs is consistent with this proposal (Amodeo et al 1992).…”

“…The failure of stomata to open when exposed to an atmosphere of low oxygen has been documented in several reports (Couchat et al 1988;Vavasseur et al 1990). It has been suggested that stomatal opening may be due to a mechanism of proton translocation involving a redox chain, in which oxygen would serve as a terminal electron acceptor (Raghavendra 1990;Gautier et al 1992).…”

Whole-cell K+ current across the plasma membrane of guard cells from a grass: Zea mays

“…Such comparisons indicate that differences in plant ionchannel kinetics may be species-dependent and highlight the need for comparative electrophysiological studies of cell types in other species, such as V. faba. The kinetics of changes in stomatal aperture are generally faster in grasses than in non-grass species (Raschke 1972;Rodriguez and Davies 1982;Johnsson et al 1976;Grantz and Zeiger 1986;Vavasseur et al 1988Vavasseur et al , 1990Karlsson et al 1990). In order to evaluate the implications of K § kinetics vis-a-vis rates of stomatal response in the intact leaf it will be necessary to obtain additional information on rates of membrane hyperpolarization and depolarization, since such voltage changes regulate both channel activation and the extent of associated ion flux.…”

Photopolarization of the Fucus sp. Zygote by Blue Light Involves a Plasma Membrane Redox Chain

“…However, it is likely that BL creates a labile memory of a map of BL intensities on the plasma membrane. A transient memorization of BL signal has been demonstrated in stomatal guard cells (Vavasseur et al, 1990). This phenomenon could be explained by BL-induced phosphorylation of specific proteins (Chory, 1993).…”