Overexpression of plasma membrane H ⁺ -ATPase in guard cells promotes light-induced stomatal opening and enhances plant growth

Abstract

Stomatal pores surrounded by a pair of guard cells in the plant epidermis control gas exchange between plants and the atmosphere in response to light, CO 2 , and the plant hormone abscisic acid. Light-induced stomatal opening is mediated by at least three key components: the blue light receptor phototropin (phot1 and phot2), plasma membrane H + -ATPase, and plasma membrane inward-rectifying K + channels. Very few attempts have been made to enhance stomatal opening with the goal of increasing photosynthesis and plant growth, even though stomatal resistance is thought to be the major limiting factor for CO 2 uptake by plants. Here, we show that transgenic Arabidopsis plants overexpressing H + -ATPase using the strong guard cell promoter GC1 showed enhanced light-induced stomatal opening, photosynthesis, and plant growth. The transgenic plants produced larger and increased numbers of rosette leaves, with ∼42-63% greater fresh and dry weights than the wild type in the first 25 d of growth. The dry weights of total flowering stems of 45-d-old transgenic plants, including seeds, siliques, and flowers, were ∼36-41% greater than those of the wild type. In addition, stomata in the transgenic plants closed normally in response to darkness and abscisic acid. In contrast, the overexpression of phototropin or inward-rectifying K + channels in guard cells had no effect on these phenotypes. These results demonstrate that stomatal aperture is a limiting factor in photosynthesis and plant growth, and that manipulation of stomatal opening by overexpressing H + -ATPase in guard cells is useful for the promotion of plant growth.Arabidopsis thaliana | stomatal conductance | photosynthetic rate | biomass

Stomatal Size, Speed, and Responsiveness Impact on Photosynthesis and Water Use Efficiency

“…To the extent of our current knowledge, the results confirm past observations from a number of mutants, including the K + channel gork (Hosy et al, 2003), the anion channel slac1 (Negi et al, 2008;Wang et al, 2012), the ost2 H + -ATPase mutant (Merlot et al, 2007), the clca H + -Cl 2 antiporter mutant (De Angeli et al, 2006), and the tpk1 K + channel mutant (Gobert et al, 2007). They are supported, additionally, by the work of Wang et al (2014b), who concurrent with this publication reported the effects of overexpressing the several K + channels and the AHA2 H + -ATPase in Arabidopsis guard cells. Their results confirm the lack of effect on channel overexpression; they also demonstrate enhanced apertures, g s , and A with H + -ATPase overexpression.…”

Global Sensitivity Analysis of OnGuard Models Identifies Key Hubs for Transport Interaction in Stomatal Dynamics

“…Using step changes in light intensity simplified the analysis. Incorporating the spectral definitions brings the OnGuard platform into alignment with current knowledge of the actions of light, especially of blue light, on the H + -ATPases (Takemiya et al, 2013;Wang et al, 2014b;Yamauchi et al, 2016) and will allow future refinements in model design, but it had no material effect on model output in our formulation.…”

The abiotic stress response and adaptation of triticale — A review

“…Productive genotypes which also sustain growth and yield under variable moisture and temperature conditions express higher stomatal conductance and gas exchange (Shimshi and Ephrat 1975;Fischer et al 1998;Horie et al 2006;Blum 2011;Reynolds et al 2012;Blum 2013;Wang et al 2014). A study of triticale and durum wheat materials grown over different field environments (Motzo et al 2013) indicated that triticale had a consistently greater stomatal conductance than durum wheat during the vegetative stage and that this was associated with a respectively greater RUE.…”