Trehalose‐6‐phosphate phosphatase E modulates ABA‐controlled root growth and stomatal movement in Arabidopsis

Abstract

Trehalose plays important roles in plant growth and stress responses and is synthesized from trehalose-6-phosphate by trehalose-6-phosphate phosphatase (TPP). Here, we show that trehalose and abscisic acid (ABA) have synergistic effects on root growth and stomatal closure. The Arabidopsis thaliana genome contains ten genes encoding TPPs and the expression level of one, TPPE, and trehalose contents increased in response to ABA. In the presence of ABA, the ABA-responsive transcription factor ABA RESPONSE ELEMENT BINDING FACTOR2 (ABF2) directly binds to the TPPE promoter to activate its expression. Genetic analysis revealed that TPPE acts downstream of ABF2, which is supported by the findings that TPPE expression and trehalose content are reduced in the abf2 mutant and that a mutation in TPPE abolished the ABA-sensitive root elongation phenotype of 35S:ABF2 plants. Reactive oxygen species (ROS) accumulation in response to ABA failed to occur in tppe mutant plants, suggesting that TPPE is involved in ABA-controlled root elongation and stomatal movement by inducing ROS accumulation. This study uncovers a new branch of the ABA signaling pathway and provides a molecular basis for the role of trehalose in plant responses to abiotic stress.

The application of a biostimulant based on tannins affects root architecture and improves tolerance to salinity in tomato plants

“…T6P, an highly soluble and low molecular weight compound, works as osmoprotectant by enhancing the resistance against salt stress 52 . Moreover, T6PP expression and trehalose content are increased in response to ABA and the synergistic action between the disaccharide and ABA also leads to a positive effect on root elongation in Arabidopsis 53 . ABA 8′-hydrolase, is a cytochrome P450 enzyme, involved in ABA catabolism, and importantly in maintaining the hormone balance 54 .…”

COP1 promotes ABA‐induced stomatal closure by modulating the abundance of ABI/HAB and AHG3 phosphatases

“…Measurements of stomatal aperture were performed as described previously (Wang et al ., 2020). Briefly, epidermal peels were stripped from leaves of 4‐wk‐old plants grown in a glasshouse under the conditions described in the previous paragraph, and incubated in the resting buffer for 2.5 h under a light intensity of 150 μmol m −2 s −1 or in the dark with or without 1 μM ABA.…”

Flavonoids improve drought tolerance of maize seedlings by regulating the homeostasis of reactive oxygen species

“…Studies have shown that almost all factors of stomatal closure can induce H 2 O 2 accumulation, and the H 2 O 2 level in guard cells directly affects the stomatal closure process (Mittler and Blumwald 2015;Singh et al 2017;Qi et al 2018;Islam et al 2019). Wang et al (2020) reported that TPPE, Arabidopsis trehalose-6-phosphate phosphatase E, participates in ABAinduced ROS accumulation and stomatal movement regulation, and H 2 O 2 accumulation induced by ABA failed to occur in tppe mutant plants. Flavonols, a group of flavonoids, have recently been shown to be involved in guard cell H 2 O 2 accumulation and stomatal movement (An et al 2016a;Watkins et al 2017;Brunetti et al 2018Brunetti et al , 2019.…”