title: Increased Sucrose Accumulation Regulates Iron-Deficiency Responses by Promoting Auxin Signaling in Arabidopsis Plants.
abstract: Previous studies have identified that auxins acts upstream of nitric oxide in regulating iron deficiency responses in roots, but the upstream signaling molecule of auxins remains unknown. In this study, we showed that Fe deficiency increased sucrose (Suc) level in roots of Arabidopsis (Arabidopsis thaliana). Exogenous application of Suc further stimulated Fe deficiency-induced ferric-chelate-reductase (FCR) activity and expression of Fe acquisition-related genes FRO2, IRT1, and FIT in roots. The opposite patterns were observed in the dark treatment. In addition, FCR activity and expression of Fe acquisition-related genes were higher in the Suc high-accumulating transgenic plant 35S::SUC2 but were lower in the Suc low-accumulating mutant suc2-5 compared with wild-type plants under Fe-deficient conditions. Consequently, Fe deficiency tolerance was enhanced in 35S::SUC2 but was compromised in suc2-5. Exogenous Suc also increased root β-glucuronidase (GUS) activity in auxin-inducible reporter DR5-GUS transgenic plants under Fe deficiency. However, exogenous Suc failed to increase FCR activity and expression of Fe acquisition-related genes in the auxin transport-impaired mutants aux1-7 and pin1-1 as well as in the wild-type plants treated with an auxin transport inhibitor under Fe deficiency. In summary, we found that increased Suc accumulation is required for regulating Fe deficiency responses in plants, with auxins acting downstream in transmitting the Fe deficiency signal.
authors.affiliation: Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource and Environmental Sciences, Zhejiang University, Hangzhou 310058, China (X.Y.L., Y.Q.Y., S.K.F., C.W.J.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, PR China (S.J.Z.).
authors.forename: Xian Yong
authors.initials: XY
authors.lastname: Lin
authors.affiliation: Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource and Environmental Sciences, Zhejiang University, Hangzhou 310058, China (X.Y.L., Y.Q.Y., S.K.F., C.W.J.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, PR China (S.J.Z.).
authors.forename: Yi Quan
authors.initials: YQ
authors.lastname: Ye
authors.affiliation: Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource and Environmental Sciences, Zhejiang University, Hangzhou 310058, China (X.Y.L., Y.Q.Y., S.K.F., C.W.J.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, PR China (S.J.Z.).
authors.forename: Shi Kai
authors.initials: SK
authors.lastname: Fan
authors.affiliation: Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource and Environmental Sciences, Zhejiang University, Hangzhou 310058, China (X.Y.L., Y.Q.Y., S.K.F., C.W.J.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, PR China (S.J.Z.) jincw@zju.edu.cn.
authors.forename: Chong Wei
authors.identifier: http://orcid.org/0000-0003-0896-8596
authors.initials: CW
authors.lastname: Jin
authors.affiliation: Key Laboratory of Environment Remediation and Ecological Health, College of Natural Resource and Environmental Sciences, Zhejiang University, Hangzhou 310058, China (X.Y.L., Y.Q.Y., S.K.F., C.W.J.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, PR China (S.J.Z.).
authors.forename: Shao Jian
authors.identifier: http://orcid.org/0000-0002-3336-8165
authors.initials: SJ
authors.lastname: Zheng
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D002244:Carbon / Q000494:pharmacology; D003624:Darkness; D060146:Ecotype; D007210:Indoleacetic Acids / Q000378:metabolism*; D000090463:Iron Deficiencies; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D055442:Metabolome / Q000187:drug effects; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D030821:Plants, Genetically Modified; D015398:Signal Transduction / Q000187:drug effects; D013395:Sucrose / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D002244:Carbon; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; D010940:Plant Proteins; D013395:Sucrose; C501411:FIT1 protein, Arabidopsis; C078729:sucrose transport protein, plant