title: The rice OsNAC6 transcription factor orchestrates multiple molecular mechanisms involving root structural adaptions and nicotianamine biosynthesis for drought tolerance.
abstract: Drought has a serious impact on agriculture worldwide. A plant's ability to adapt to rhizosphere drought stress requires reprogramming of root growth and development. Although physiological studies have documented the root adaption for tolerance to the drought stress, underlying molecular mechanisms is still incomplete, which is essential for crop engineering. Here, we identified OsNAC6-mediated root structural adaptations, including increased root number and root diameter, which enhanced drought tolerance. Multiyear drought field tests demonstrated that the grain yield of OsNAC6 root-specific overexpressing transgenic rice lines was less affected by drought stress than were nontransgenic controls. Genome-wide analyses of loss- and gain-of-function mutants revealed that OsNAC6 up-regulates the expression of direct target genes involved in membrane modification, nicotianamine (NA) biosynthesis, glutathione relocation, 3'-phophoadenosine 5'-phosphosulphate accumulation and glycosylation, which represent multiple drought tolerance pathways. Moreover, overexpression of NICOTIANAMINE SYNTHASE genes, direct targets of OsNAC6, promoted the accumulation of the metal chelator NA and, consequently, drought tolerance. Collectively, OsNAC6 orchestrates novel molecular drought tolerance mechanisms and has potential for the biotechnological development of high-yielding crops under water-limiting conditions.
authors.affiliation: Graduate School of International Agricultural Technology and Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang, Korea.
authors.forename: Dong-Keun
authors.initials: DK
authors.lastname: Lee
authors.affiliation: Graduate School of International Agricultural Technology and Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang, Korea.
authors.forename: Pil Joong
authors.initials: PJ
authors.lastname: Chung
authors.affiliation: Graduate School of International Agricultural Technology and Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang, Korea.
authors.forename: Jin Seo
authors.initials: JS
authors.lastname: Jeong
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea.
authors.forename: Geupil
authors.initials: G
authors.lastname: Jang
authors.affiliation: Graduate School of International Agricultural Technology and Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang, Korea.
authors.forename: Seung Woon
authors.initials: SW
authors.lastname: Bang
authors.affiliation: Graduate School of International Agricultural Technology and Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang, Korea.
authors.forename: Harin
authors.initials: H
authors.lastname: Jung
authors.affiliation: Graduate School of International Agricultural Technology and Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang, Korea.
authors.forename: Youn Shic
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Genetic Engineering and Graduate School of Biotechnology, Kyung Hee University, Yongin, Korea.
authors.forename: Sun-Hwa
authors.initials: SH
authors.lastname: Ha
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea.
authors.forename: Yang Do
authors.initials: YD
authors.lastname: Choi
authors.affiliation: Graduate School of International Agricultural Technology and Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang, Korea.
authors.forename: Ju-Kon
authors.initials: JK
authors.lastname: Kim
mesh_terms: D001383:Azetidinecarboxylic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001709:Biotechnology; D055864:Droughts; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D055106:Genome-Wide Association Study; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; C082893:nicotianamine; D001383:Azetidinecarboxylic Acid
keywords: NAC transcription factor; biotechnology; drought; nicotianamine; rice; root