Hydrogen Peroxide Is Involved in Abscisic Acid-Induced Stomatal Closure in Vicia faba  

Abstract

One of the most important functions of the plant hormone abscisic acid (ABA) is to induce stomatal closure by reducing the turgor of guard cells under water deficit. Under environmental stresses, hydrogen peroxide (H 2 O 2 ), an active oxygen species, is widely generated in many biological systems. Here, using an epidermal strip bioassay and laser-scanning confocal microscopy, we provide evidence that H 2 O 2 may function as an intermediate in ABA signaling in Vicia faba guard cells. H 2 O 2 inhibited induced closure of stomata, and this effect was reversed by ascorbic acid at concentrations lower than 10 Ϫ5 m. Further, ABA-induced stomatal closure also was abolished partly by addition of exogenous catalase (CAT) and diphenylene iodonium (DPI), which are an H 2 O 2 scavenger and an NADPH oxidase inhibitor, respectively. Time course experiments of single-cell assays based on the fluorescent probe dichlorofluorescein showed that the generation of H 2 O 2 was dependent on ABA concentration and an increase in the fluorescence intensity of the chloroplast occurred significantly earlier than within the other regions of guard cells. The ABA-induced change in fluorescence intensity in guard cells was abolished by the application of CAT and DPI. In addition, ABA microinjected into guard cells markedly induced H 2 O 2 production, which preceded stomatal closure. These effects were abolished by CAT or DPI micro-injection. Our results suggest that guard cells treated with ABA may close the stomata via a pathway with H 2 O 2 production involved, and H 2 O 2 may be an intermediate in ABA signaling.

Sphingosine-1-phosphate (S1P) mediates darkness-induced stomatal closure through raising cytosol pH and hydrogen peroxide (H2O2) levels in guard cells in Vicia faba

“…The ability of guard cells to generate H 2 O 2 has been demonstrated in Nicotiana tabacum, L. esculentum, and C. communis [38,39]. The finding that ABA promotes H 2 O 2 synthesis in A. thaliana and V. faba guard cells was a significant advance, which further highlighted the fact that endogenous H 2 O 2 acts as an intermediate signal in ABA signaling in guard cells [40,41]. In addition, H 2 O 2 has also been shown to mediate MJ-, salicylic acid (SA)-, cytokinin-, auxin-, ethylene-, elicitor-, high CO 2 concentrations-, CO-, and UV-B-regulated stomatal movement [27,38,39,4247].…”

“…Nevertheless, whether H 2 O 2 participates in S1P-induced stomatal closure is still unknown. The results that S1P and H 2 O 2 mediate ABA-induced stomatal closure [5,14,40,41,58] and S1P also reduces stomatal aperture [5,14], this study promoted us to investigate the effect of S1P on H 2 O 2 production in guard cells during darkness-induced stomatal closure. Our results indicated that exogenous S1P induced H 2 O 2 production, and that darkness caused S1P synthesis and H 2 O 2 production.…”

Rapid plant rehydration initiates permanent and adverse changes in the photosynthetic apparatus of triticale

“…Changes in the parameters of chlorophyll fluorescence and photosynthetic activity, observed 7 days after finishing the drought period during R1 rehydration, were probably due to damage to the photosynthetic apparatus caused by ROS, including hydrogen peroxide (Miller et al 2010). Moreover, hydrogen peroxide is involved in abscisic acid-induced stomatal closure (Zhang et al 2001;Bright et al 2006;Miao et al 2006), which may be another reason for reduced photosynthetic activity after 7 days of R1 or R3 treatment.…”

Directed-spray application of paraquat and diuron in physic nut plants

“…Therefore, it can be inferred that diuron had negative effects on net photosynthesis, probably as a result of damage to the leaf tissue after the production of peroxides in the inhibition of electron flow in OS II, which consequently induced the production of abscisic acid (ABA) and stomatal closure, because these effects reduce stomatal conductance and CO 2 in the inner space of the leaf (Zhang et al 2001;Tironi et al 2010). The reduction in leaf transpiration can also be a result of oxidative stress induced by the action of diuron.…”