title: A novel thiol-reductase activity of Arabidopsis YUC6 confers drought tolerance independently of auxin biosynthesis.
abstract: YUCCA (YUC) proteins constitute a family of flavin monooxygenases (FMOs), with an important role in auxin (IAA) biosynthesis. Here we report that Arabidopsis plants overexpressing YUC6 display enhanced IAA-related phenotypes and exhibit improved drought stress tolerance, low rate of water loss and controlled ROS accumulation under drought and oxidative stresses. Co-overexpression of an IAA-conjugating enzyme reduces IAA levels but drought stress tolerance is unaffected, indicating that the stress-related phenotype is not based on IAA overproduction. YUC6 contains a previously unrecognized FAD- and NADPH-dependent thiol-reductase activity (TR) that overlaps with the FMO domain involved in IAA biosynthesis. Mutation of a conserved cysteine residue (Cys-85) preserves FMO but suppresses TR activity and stress tolerance, whereas mutating the FAD- and NADPH-binding sites, that are common to TR and FMO domains, abolishes all outputs. We provide a paradigm for a single protein playing a dual role, regulating plant development and conveying stress defence responses.
authors: Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors: Joon-Yung
authors: JY
authors: Cha
authors: Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors: Woe-Yeon
authors: WY
authors: Kim
authors: Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors: Sun Bin
authors: SB
authors: Kang
authors: Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907, USA.
authors: Jeong Im
authors: JI
authors: Kim
authors: Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors: Dongwon
authors: D
authors: Baek
authors: Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors: In Jung
authors: IJ
authors: Jung
authors: Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors: Mi Ri
authors: MR
authors: Kim
authors: Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors: Ning
authors: N
authors: Li
authors: Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors: Hyun-Jin
authors: HJ
authors: Kim
authors: Department of Applied Biological Chemistry, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan.
authors: Masatoshi
authors: M
authors: Nakajima
authors: Department of Applied Biological Chemistry, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.|Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan.|Department of Biochemistry, King Abdulaziz University, Jeddah 21589, Kingdom of Saudi Arabia.
authors: Tadao
authors: T
authors: Asami
authors: Biotechnology Research Group, Department of Biological Science, Faculty of Science, King Abdulaziz University, Jeddah 21589, Kingdom of Saudi Arabia.
authors: Jamal S M
authors: JS
authors: Sabir
authors: Department of Ecological Adaptation, National Institute of Ecology, Seocheon 325-813, Republic of Korea.
authors: Hyeong Cheol
authors: HC
authors: Park
authors: Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors: Sang Yeol
authors: SY
authors: Lee
authors: Biotechnology Research Group, Department of Biological Science, Faculty of Science, King Abdulaziz University, Jeddah 21589, Kingdom of Saudi Arabia.|Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors: Hans J
authors: HJ
authors: Bohnert
authors: Biotechnology Research Group, Department of Biological Science, Faculty of Science, King Abdulaziz University, Jeddah 21589, Kingdom of Saudi Arabia.|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907, USA.
authors: Ray A
authors: RA
authors: Bressan
authors: Instituto de Recursos Naturales y Agrobiologia, Consejo Superior de Investigaciones Cientificas, Sevilla 41012, Spain.
authors: Jose M
authors: JM
authors: Pardo
authors: Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors: Dae-Jin
authors: DJ
authors: Yun
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D018384:Oxidative Stress / Q000235:genetics*; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013312:Stress, Physiological / Q000235:genetics*; D013438:Sulfhydryl Compounds / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D017382:Reactive Oxygen Species; D013438:Sulfhydryl Compounds; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; C562183:YUCCA6 protein, Arabidopsis