scholarly journals Light-dependent Influx and Efflux of Potassium of Guard Cells during Stomatal Opening and Closing

1970 ◽  
Vol 46 (3) ◽  
pp. 483-487 ◽  
Author(s):  
G. D. Humble ◽  
Theodore C. Hsiao
Keyword(s):  
Guard Cells ◽  
Stomatal Opening ◽  
Opening And Closing

scholarly journals A tonoplast-localized magnesium transporter is involved in stomatal opening in Arabidopsis

2021 ◽  
Author(s):  
Shin-ichiro Inoue ◽  
Maki Hayashi ◽  
Sheng Huang ◽  
Kengo Yokosho ◽  
Eiji Gotoh ◽  
...  
Keyword(s):  
Large Scale ◽  
Light Condition ◽  
Guard Cells ◽  
Stomatal Opening ◽  
Complementation Test ◽  
Interacting Protein ◽  
Magnesium Transporter ◽  
Arabidopsis Mutant ◽  
Opening And Closing

Abstract Plant stomata play an important role in CO2 uptake for photosynthesis and transpiration, but the mechanisms underlying stomatal opening and closing are still not completely understood. Here, through large-scale screening, we identified an Arabidopsis mutant (cst2 for closed stomata2) defective in stomatal opening under light condition. A map-based cloning combined with complementation test revealed that the mutant phenotype was caused by a nucleotide substitution of a gene, which domains show similarity to human Mg efflux transporter ACDP/CNNM. Functional analysis showed that CST2 encodes a tonoplast-localized transporter for Mg. This protein is constitutively and highly expressed in the guard cells. Furthermore, CST2 is phosphorylated by calcineurin B-like protein (CBL)-interacting protein kinases 26 (CIPK26) in vitro, which is probably required for its activation. Knockout of this gene resulted in stomatal closing and growth retardation under high Mg concentration conditions, while over-expression of this gene increased tolerance to high Mg. Our results indicate that CST2 plays an important role in maintaining Mg homeostasis in plant cells through sequestering Mg into vacuoles especially in guard cells and that this homeostasis is required for stomatal opening, which provide a novel insight into mechanism of stomatal opening in plants.

scholarly journals A multi-phase flux balance model reveals flexibility of guard cell central carbon metabolism

2020 ◽  
Author(s):  
Joshua XL Tan ◽  
C. Y. Maurice Cheung
Keyword(s):  
Guard Cell ◽  
Cell Function ◽  
Cell Metabolism ◽  
Guard Cells ◽  
Stomatal Opening ◽  
Diel Cycle ◽  
Balance Model ◽  
Metabolic Processes ◽  
Flux Balance ◽  
Opening And Closing

SummaryExperimental research in guard cell metabolism has revealed the roles of the accumulation of various metabolites in guard cell function, but a comprehensive understanding of their metabolism over the diel cycle is still incomplete, given the limitations of current experimental methods. In this study, we constructed a four-phase flux balance model of guard cell metabolism to investigate the changes in guard cell metabolism over the diel cycle, including the day and night and stomata opening and closing. Our model demonstrated the metabolic flexibility in guard cells, showing that multiple metabolic processes can contribute to the synthesis and metabolism of malate and sucrose as osmolytes during stomatal opening and closing. We showed that guard cells can adapt to varying light availability and sucrose uptake from the apoplast during the day by operating in a mixotrophic mode with a switch between sucrose synthesis via the Calvin-Benson cycle and sucrose degradation via the oxidative pentose phosphate pathway. During stomatal opening, our model predicted an alternative flux mode of the Calvin-Benson cycle with all dephosphorylating steps diverted to diphosphate—fructose-6-phosphate 1-phosphotransferase to produce PPi, which is used to pump protons across the tonoplast for the accumulation of osmolytes. An analysis of the energetics of the use of different osmolytes in guard cells showed that malate and Cl- are similarly efficient as the counterion of K+ during stomatal opening.Significance statementThis work presents the first four-phase metabolic model for predicting guard cell metabolism over the diel cycle, which predicted an alternative flux model of the Calvin-Benson cycle that maximises the production of PPi during stomatal opening. While multiple metabolic processes were shown be important in synthesising and metabolising osmolytes in guard cells of different experimental systems, our model demonstrated that these processes can operate simultaneously and at different rates depending on conditions.

scholarly journals Overexpression of Plasma Membrane H+-ATPase in Guard Cells Enhances Light-Induced Stomatal Opening, Photosynthesis, and Plant Growth in Hybrid Aspen

2021 ◽  
Vol 12 ◽  
Author(s):  
Shigeo Toh ◽  
Naoki Takata ◽  
Eigo Ando ◽  
Yosuke Toda ◽  
Yin Wang ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Transgenic Plants ◽  
Woody Plants ◽  
Stem Elongation ◽  
Guard Cells ◽  
Gus Expression ◽  
Stomatal Opening ◽  
Wild Type ◽  
Exchange System ◽  
Gas Exchange System

Stomata in the plant epidermis open in response to light and regulate CO2 uptake for photosynthesis and transpiration for uptake of water and nutrients from roots. Light-induced stomatal opening is mediated by activation of the plasma membrane (PM) H+-ATPase in guard cells. Overexpression of PM H+-ATPase in guard cells promotes light-induced stomatal opening, enhancing photosynthesis and growth in Arabidopsis thaliana. In this study, transgenic hybrid aspens overexpressing Arabidopsis PM H+-ATPase (AHA2) in guard cells under the strong guard cell promoter Arabidopsis GC1 (AtGC1) showed enhanced light-induced stomatal opening, photosynthesis, and growth. First, we confirmed that AtGC1 induces GUS expression specifically in guard cells in hybrid aspens. Thus, we produced AtGC1::AHA2 transgenic hybrid aspens and confirmed expression of AHA2 in AtGC1::AHA2 transgenic plants. In addition, AtGC1::AHA2 transgenic plants showed a higher PM H+-ATPase protein level in guard cells. Analysis using a gas exchange system revealed that transpiration and the photosynthetic rate were significantly increased in AtGC1::AHA2 transgenic aspen plants. AtGC1::AHA2 transgenic plants showed a>20% higher stem elongation rate than the wild type (WT). Therefore, overexpression of PM H+-ATPase in guard cells promotes the growth of perennial woody plants.

Cytokinin- and auxin-induced stomatal opening involves a decrease in levels of hydrogen peroxide in guard cells of Vicia faba

2006 ◽  
Vol 33 (6) ◽  
pp. 573 ◽  
Author(s):  
Xi-Gui Song ◽  
Xiao-Ping She ◽  
Jun-Min He ◽  
Chen Huang ◽  
Tu-sheng Song
Keyword(s):  
Hydrogen Peroxide ◽  
Vicia Faba ◽  
Laser Scanning ◽  
Guard Cells ◽  
Laser Scanning Confocal Microscopy ◽  
Stomatal Opening ◽  
Scanning Confocal Microscopy ◽  
Diphenylene Iodonium ◽  
The Relationship ◽  
Exogenous H2o2

Previous studies have shown that cytokinins and auxins can induce the opening of stomata. However, the mechanism of stomatal opening caused by cytokinins and auxins remains unclear. The purpose of this paper is to investigate the relationship between hydrogen peroxide (H2O2) levels in guard cells and stomatal opening induced by cytokinins and auxins in Vicia faba. By means of stomatal bioassay and laser-scanning confocal microscopy, we provide evidence that cytokinins and auxins reduced the levels of H2O2 in guard cells and induced stomatal opening in darkness. Additionally, cytokinins not only reduced exogenous H2O2 levels in guard cells caused by exposure to light, but also abolished H2O2 that had been generated during a dark period, and promoted stomatal opening, as did ascorbic acid (ASA, an important reducing substrate for H2O2 removal). However, unlike cytokinins, auxins did not reduce exogenous H2O2, did not abolish H2O2 that had been generated in the dark, and therefore did not promote reopening of stoma induced to close in the dark. The above-mentioned effects of auxins were similar to that of diphenylene iodonium (DPI, an inhibitor of the H2O2-generating enzyme NADPH oxidase). Taken together our results indicate that cytokinins probably reduce the levels of H2O2 in guard cells by scavenging, whereas auxins limit H2O2 levels through restraining H2O2 generation, inducing stomatal opening in darkness.

scholarly journals Sucrose breakdown within guard cells provides substrates for glycolysis and glutamine biosynthesis during light‐induced stomatal opening

2018 ◽  
Vol 94 (4) ◽  
pp. 583-594 ◽  
Author(s):  
David B. Medeiros ◽  
Leonardo Perez Souza ◽  
Werner C. Antunes ◽  
Wagner L. Araújo ◽  
Danilo M. Daloso ◽  
...  
Keyword(s):  
Guard Cells ◽  
Stomatal Opening

scholarly journals Raf-like kinases CBC1 and CBC2 negatively regulate stomatal opening by negatively regulating plasma membrane H+-ATPase phosphorylation in Arabidopsis

2020 ◽  
Vol 19 (1) ◽  
pp. 88-98 ◽  
Author(s):  
Maki Hayashi ◽  
Hodaka Sugimoto ◽  
Hirotaka Takahashi ◽  
Motoaki Seki ◽  
Kazuo Shinozaki ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Blue Light ◽  
Guard Cells ◽  
Stomatal Opening

Raf-like kinases CBC1 and CBC2 negatively regulate phosphorylation of plasma membrane H+-ATPase in guard cells and blue light-dependent stomatal opening.

scholarly journals Stomatal State Identification and Classification in Quinoa Microscopic Imprints through Deep Learning

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Abdul Razzaq ◽  
Sharaiz Shahid ◽  
Muhammad Akram ◽  
Muhammad Ashraf ◽  
Shahid Iqbal ◽  
...  
Keyword(s):  
Automatic System ◽  
Guard Cells ◽  
Support Vector ◽  
Sampling Techniques ◽  
Single Shot ◽  
State Information ◽  
State Identification ◽  
Svm Algorithm ◽  
Main Medium ◽  
Opening And Closing

Stomata are the main medium of plants for the trade of water, regulate the gas exchange, and are responsible for the process of photosynthesis and transpiration. The stomata are surrounded by guard cells, which help to control the rate of transpiration by opening and closing the stomata. The stomata states (open and close) play a significant role in describing the plant’s health. Moreover, stomata counting is important for scientists to investigate the numbers of stomata that are open and those that are closed to measure their density and distribution on the surface of leaves through different sampling techniques. Although a few techniques for stomata counting have been proposed, these approaches do not identify and classify the stomata based on their states in leaves. In this research, we have developed an automatic system for stomata state identification and counting in quinoa leaf images through the transformed learning (neural network model Single Shot Detector) approach. In leaf imprint, the state of stomata has been determined by measuring the correlation between the area of stomata and the aperture of each detected stoma in the image. The stomata states have been classified through the Support Vector Machine (SVM) algorithm. The overall identification and classification accuracy of the proposed system are 98.6% and 97%, respectively, helping researchers to obtain accurate stomatal state information for leaves in an efficient and simple way.

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