Chao Han
Shandong University
Hydrogen Peroxide is Required for Light-Induced Stomatal Opening across Different Plant Species
Stomatal movement is vital for plants to exchange gases and adaption to terrestrial habitats, which is regulated by environmental and phytohormonal signals. Here, we demonstrate that hydrogen peroxide (H
2
O
2
) is required for light-induced stomatal opening. H2O2 accumulates specifically in guard cells even when plants under unstressed conditions. Reducing H
2
O
2
content through chemical treatments or genetic manipulations results in impaired stomatal opening in response to light. This phenomenon is observed across different plant species, including lycopodium, fern, monocotyledonous wheat. Additionally, we show that H
2
O
2
induces the nuclear localization of KIN10 protein, the catalytic subunit of plant energy sensor SnRK1. The nuclear localized KIN10 interacts with and phosphorylates the bZIP transcription factor bZIP30, leading to the formation of a heterodimer between bZIP30 and BRASSINAZOLE-RESISTANT1 (BZR1), the master regulator of brassinosteroid signaling. This heterodimer complex activates the expression of amylase, which enables guard cell starch degradation and promotes stomatal opening. Overall, these findings suggest that H
2
O
2
plays a critical role in light-induced stomatal opening across different plant species.
Title of presentation
Sugar Signaling Regulates Light Induced Stomatal Opening
Authors
Wen. Shi, Mingyi. Bai, Chao. Han
The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao 266237, China.
Abstract
Recent advances showed that carbohydrate metabolism is essential for light induced stomatal opening. Starch in guard cells degrades quickly upon light exposure. Phosphoproteomic analysis revealed that ß-amylase 1 (BAM1), which is specifically expressed in guard cells and responsible for starch degradation, is potential target of Target of Rapamycin (TOR). TOR kinase stabilizes BAM1 by directly phosphorylating Serine 31, thereby promoting guard cell starch degradation and stomatal opening. Meanwhile, stomata is high energy demanded organ and possesses higher ability of respiration, leading to guard cell specific accumulation of hydrogen peroxide (H2O2) under unstressed condition. Guard cell specific accumulated H2O2 is required for light induced starch degradation and stomatal opening. This phenomenon is conserved among plant species with different stomata types and basal vascular plants. H2O2 promotes guard cell starch degradation and stomatal opening through KIN10, the catalytic subunit of SnRK1. KIN10 prefers nuclear localization caused by H2O2 accumulation in guard cells and phosphorylates bZIP30 transcription factor promoting the expression of BAM1. bZIP30 forms transcriptional complex with BZR1, the core transcription factor of Brassinosteroid signaling, through the KIN10 dependent phosphorylation of bZIP30 and BZR1 oxidation. And the molecular mechanism of KIN10-bZIP30-BZR1 module also exists in Selaginella doederleinii. Our study unveils that metabolic statues regulates light induce stomatal opening through TOR and SnRK1 signaling.
My Sessions
Sugar Signaling Regulates Light Induced Stomatal Opening
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Presentation