Stomatal responses to carbon dioxide and light require abscisic acid catabolism in Arabidopsis

Abstract

In plants, stomata control water loss and CO 2 uptake. The aperture and density of stomatal pores, and hence the exchange of gases between the plant and the atmosphere, are controlled by internal factors such as the plant hormone abscisic acid (ABA) and external signals including light and CO 2 . In this study, we examine the importance of ABA catabolism in the stomatal responses to CO 2 and light. By using the ABA 8′-hydroxylase-deficient Arabidopsis thaliana double mutant cyp707a1 cyp707a3 , which is unable to break down and instead accumulates high levels of ABA, we reveal the importance of the control of ABA concentration in mediating stomatal responses to CO 2 and light. Intriguingly, our experiments suggest that endogenously produced ABA is unable to close stomata in the absence of CO 2 . Furthermore, we show that when plants are grown in short day conditions ABA breakdown is required for the modulation of both elevated [CO 2 ]-induced stomatal closure and elevated [CO 2 ]-induced reductions in leaf stomatal density. ABA catabolism is also required for the stomatal density response to light intensity, and for the full range of light-induced stomatal opening, suggesting that ABA catabolism is critical for the integration of stomatal responses to a range of environmental stimuli.

ABA signalling and metabolism are not essential for dark-induced stomatal closure but affect response speed

“…However, there is disagreement as to the precise role of ABA in stomatal responses to CO 2 , as other studies suggest that ABA and ABA signalling are required for elevated CO 2 induced stomatal closure 38 . Most recently, a study has shown ABA catabolism plays a role in regulating stomatal responses to changes in CO 2 concentration both on a physiological and developmental scale 39 . A set of control leaf discs were kept in the dark for 120 min over the same period (120 min D).…”

Transcriptome Profiling of Transposon-Derived Long Non-coding RNAs Response to Hormone in Strawberry Fruit Development

“…ABA is an essential hormone regulating plants tolerant to abiotic and biotic stress ( Lee and Luan, 2012 ; Danquah et al, 2014 ). It is well known that ABA induces the closure of stoma to reduce evaporation ( Hsu et al, 2021 ; Movahedi et al, 2021 ). Hence in the GO analysis at ABA treatment, the module contained genes responding to heat and temperature.…”

Polyamine Metabolism under Different Light Regimes in Wheat

“…Light has also been suggested to regulate ABA biosynthesis directly or indirectly [68], however, the literature data on the light-induced changes in ABA content are contradictory [69][70][71][72]. Earlier findings suggested a positive feedback loop between ABA and PAs [61,73].…”