The Copper Amine Oxidase AtCuAOδ Participates in Abscisic Acid-Induced Stomatal Closure in Arabidopsis

Abstract

Plant copper amine oxidases (CuAOs) are involved in wound healing, defense against pathogens, methyl-jasmonate-induced protoxylem differentiation, and abscisic acid (ABA)-induced stomatal closure. In the present study, we investigated the role of the Arabidopsis thaliana CuAOδ (AtCuAOδ; At4g12290) in the ABA-mediated stomatal closure by genetic and pharmacological approaches. Obtained data show that AtCuAOδ is up-regulated by ABA and that two Atcuaoδ T-DNA insertional mutants are less responsive to this hormone, showing reduced ABA-mediated stomatal closure and H2O2 accumulation in guard cells as compared to the wild-type (WT) plants. Furthermore, CuAO inhibitors, as well as the hydrogen peroxide (H2O2) scavenger N,N1-dimethylthiourea, reversed most of the ABA-induced stomatal closure in WT plants. Consistently, AtCuAOδ over-expressing transgenic plants display a constitutively increased stomatal closure and increased H2O2 production compared to WT plants. Our data suggest that AtCuAOδ is involved in the H2O2 production related to ABA-induced stomatal closure.

Mutation of Arabidopsis Copper-Containing Amine Oxidase Gene AtCuAOδ Alters Polyamines, Reduces Gibberellin Content and Affects Development

“…AtCuAOδ (At4g12290) encodes an enzyme predicted to localise in plastids [ 17 ], although it has also been identified in the rosette leaf vacuole proteome [ 18 ]. The expression of AtCuAOδ appears to be primarily in mature seeds and senescent leaves but is also expressed highly in the hypocotyl, guard cells, sepals and stigma [ 19 , 20 ]. Expression of AtCuAOδ is also up-regulated by pathogens and Pep2, a peptide which activates the innate immune response [ 21 ], as well as a range of abiotic stresses and ABA.…”

Leaf-Wounding Long-Distance Signaling Targets AtCuAOβ Leading to Root Phenotypic Plasticity

“…The first cDNA strand was synthesized using random and oligo dT primers in an iCycler TM Thermal Cycler (Bio-Rad) with the following parameters: 25 AtCuAOβ specific primers were RT-qPCR-AtCuAOβ-for/rev [11]. Ubiquitin-conjugating enzyme 21 (UBC21, At5g25760) was used as reference gene (UBC21-for/rev; [43]). The software used to control the thermocycler and to analyze data was the Corbett Rotor-Gene 6000 Application Software (version 1.7, Build 87; Corbett Life Science, QIAGEN, Milan, Italy).…”

“…The software used to control the thermocycler and to analyze data was the Corbett Rotor-Gene 6000 Application Software (version 1.7, Build 87; Corbett Life Science, QIAGEN, Milan, Italy). Fold change in the expression of the AtCuAOβ gene were calculated according to the ∆∆C q method as previously described [43,44].…”

H2O2/ABA signal pathway participates in the regulation of stomata opening of cucumber leaves under salt stress by putrescine

“…However, it is still unclear how to Put interacts with ABA to regulate stomatal changes during stomatal limitation period under salt stress and hence, we conducted the current experiment to extends our knowledge about this regulation. H 2 O 2 is produced by the catalysis of PAs catabolism enzyme DAO and PAO, which are located in the apoplast and plays an important role in plant defense against abiotic stresses (Alcázar et al, 2010;Tavladoraki et al, 2012;Guo et al, 2014;Fraudentali et al, 2019). The other two enzymes that catalyze the production of H 2 O 2 are NOX and CWPOD (Rejeb et al, 2015;Passardi et al, 2004).…”