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

Abstract

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.

Discovery of 2,6-Dihalopurines as Stomata Opening Inhibitors: Implication of an LRX-Mediated H+-ATPase Phosphorylation Pathway

“…3−5 Control of stomatal movements (opening/closing) have long been considered to be critical not only to increase biomass and drought tolerance in crops, 6−8 but also to decrease global warming by reduction of carbon dioxide. 6,9 The movement of stomata happens quickly, in as little as 10 min to an hour in response to ABA, 10−12 a hormone produced in response to drought, 3 highlighting their significance as a first-line defense against environmental changes around a plant. Furthermore, stomatal movements have central roles in plant growth and other stress responses, attracting much attention, especially for agriculture purposes.…”

“…Plant stomata, consisting of a pair of guard cells, forming pores in leaf epidermis of plants, play a key role in the regulation of gas–water exchange between the plant and the atmosphere to conduct photosynthesis and transpiration . Stomata have been shown to respond to a host of environmental conditions including temperature, water availability, light intensity and CO 2 levels in leaves. − They have also been shown to respond to multiple plant hormones, namely abscisic acid (ABA), auxin, cytokinin, ethylene and jasmonic acid. − Control of stomatal movements (opening/closing) have long been considered to be critical not only to increase biomass and drought tolerance in crops, − but also to decrease global warming by reduction of carbon dioxide. , The movement of stomata happens quickly, in as little as 10 min to an hour in response to ABA, − a hormone produced in response to drought, highlighting their significance as a first-line defense against environmental changes around a plant. Furthermore, stomatal movements have central roles in plant growth and other stress responses, attracting much attention, especially for agriculture purposes.…”

Stomatal properties of Arabidopsis cauline and rice flag leaves and their contributions to seed production and grain yield

“…Up-regulated PM H + -ATPase gene expression ( AHA2 in Arabidopsis and poplar) in epidermal tissues increased the guard cell PM H + -ATPase protein level by more than 50%, and thus enhanced stomatal opening, photosynthetic activity, and plant growth ( Wang et al , 2014 ; Toh et al , 2021 ). Furthermore, up-regulated PM H + -ATPase gene expression ( OSA1 ) in whole rice plants increases the total PM H + -ATPase protein content by ~40%, leading to enhanced stomatal opening, photosynthetic activity, nutrient uptake in roots, and plant growth, with a 33% increase in grain yield even in the field ( Zhang et al , 2021 ).…”

Discovery of 2,6-Dihalopurines as Stomata Opening Inhibitors: Implication of an LRX-mediated H+-ATPase Phosphorylation Pathway

“…3,4,5 Control of stomatal movements (opening/closing) have long been considered to be critical not only to increase biomass and drought tolerance in crops, 6,7,8 but also to decrease global warming by reduction of carbon dioxide. 6,9 The movement of stomata happens quickly, in as little as 10 mins to an hour in response to ABA, 10,11,12 a hormone produced in response to drought, 3 highlighting their significance as a first-line defense against environmental changes around a plant. Furthermore, stomatal movements have central roles in plant growth and other stress responses, attracting much attention, especially for agriculture purposes.…”