title: Glutathione Regulates 1-Aminocyclopropane-1-Carboxylate Synthase Transcription via WRKY33 and 1-Aminocyclopropane-1-Carboxylate Oxidase by Modulating Messenger RNA Stability to Induce Ethylene Synthesis during Stress.
abstract: Glutathione (GSH) plays a fundamental role in plant defense-signaling network. Recently, we have established the involvement of GSH with ethylene (ET) to combat environmental stress. However, the mechanism of GSH-ET interplay still remains unexplored. Here, we demonstrate that GSH induces ET biosynthesis by modulating the transcriptional and posttranscriptional regulations of its key enzymes, 1-aminocyclopropane-1-carboxylate synthase (ACS) and 1-aminocyclopropane-1-carboxylate oxidase (ACO). Transgenic Arabidopsis (Arabidopsis thaliana) plants with enhanced GSH content (AtECS) exhibited remarkable up-regulation of ACS2, ACS6, and ACO1 at transcript as well as protein levels, while they were down-regulated in the GSH-depleted phytoalexin deficient2-1 (pad2-1) mutant. We further observed that GSH induced ACS2 and ACS6 transcription in a WRKY33-dependent manner, while ACO1 transcription remained unaffected. On the other hand, the messenger RNA stability for ACO1 was found to be increased by GSH, which explains our above observations. In addition, we also identified the ACO1 protein to be a subject for S-glutathionylation, which is consistent with our in silico data. However, S-glutathionylation of ACS2 and ACS6 proteins was not detected. Further, the AtECS plants exhibited resistance to necrotrophic infection and salt stress, while the pad2-1 mutant was sensitive. Exogenously applied GSH could improve stress tolerance in wild-type plants but not in the ET-signaling mutant ethylene insensitive2-1, indicating that GSH-mediated resistance to these stresses occurs via an ET-mediated pathway. Together, our investigation reveals a dual-level regulation of ET biosynthesis by GSH during stress.
authors.affiliation: Plant Biology Laboratory, Organic and Medicinal Chemistry Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, Kolkata 700 032, India.
authors.forename: Riddhi
authors.identifier: http://orcid.org/0000-0001-7490-190X
authors.initials: R
authors.lastname: Datta
authors.affiliation: Plant Biology Laboratory, Organic and Medicinal Chemistry Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, Kolkata 700 032, India.
authors.forename: Deepak
authors.initials: D
authors.lastname: Kumar
authors.affiliation: Plant Biology Laboratory, Organic and Medicinal Chemistry Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, Kolkata 700 032, India.
authors.forename: Asma
authors.identifier: http://orcid.org/0000-0002-7739-1025
authors.initials: A
authors.lastname: Sultana
authors.affiliation: Plant Biology Laboratory, Organic and Medicinal Chemistry Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, Kolkata 700 032, India.
authors.forename: Saptarshi
authors.initials: S
authors.lastname: Hazra
authors.affiliation: Plant Biology Laboratory, Organic and Medicinal Chemistry Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, Kolkata 700 032, India.
authors.forename: Dipto
authors.identifier: http://orcid.org/0000-0002-8013-7079
authors.initials: D
authors.lastname: Bhattacharyya
authors.affiliation: Plant Biology Laboratory, Organic and Medicinal Chemistry Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, Kolkata 700 032, India sharmila@iicb.res.in.
authors.forename: Sharmila
authors.initials: S
authors.lastname: Chattopadhyay
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D005030:Ethylenes / Q000096:biosynthesis*; D020869:Gene Expression Profiling / Q000379:methods; D018506:Gene Expression Regulation, Plant; D005978:Glutathione / Q000378:metabolism*; D008190:Lyases / Q000235:genetics* / Q000378:metabolism; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D009154:Mutation; D030821:Plants, Genetically Modified; D011523:Protoplasts / Q000378:metabolism; D020871:RNA Stability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D005030:Ethylenes; D012333:RNA, Messenger; D014157:Transcription Factors; C517860:WRKY33 protein, Arabidopsis; C036216:ethylene; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase; D005978:Glutathione