title: Involvement of endogenous salicylic acid in iron-deficiency responses in Arabidopsis.
abstract: Several phytohormones have been demonstrated to be involved in iron (Fe) homeostasis. We took advantage of a salicylic acid (SA) biosynthesis defective mutant phytoalexin deficient 4 (pad4: T-DNA Salk_089936) to explore the possible effects of endogenous SA on the morphological and physiological responses to Fe deprivation. The morphological and physiological analysis was carried out between Col-0 and the pad4 mutant. Under an Fe-deficiency treatment, Col-0 showed more severe leaf chlorosis and root growth inhibition compared with the pad4 mutant. The soluble Fe concentrations were significantly higher in pad4 than in Col-0 under the Fe-deficiency treatment. Fe deficiency significantly induced SA accumulation in Col-0 and the loss-of-function of PAD4 blocked this process. The requirement of endogenous SA accumulation for Fe-deficiency responses was confirmed using a series of SA biosynthetic mutants and transgenic lines. Furthermore, a comparative RNA sequencing analysis of the whole seedling transcriptomes between Col-0 and the pad4 mutant was also performed. Based on the transcriptome data, the expression levels of many auxin- and ethylene-response genes were altered in pad4 compared with Col-0. Fe deficiency increases SA contents which elevates auxin and ethylene signalling, thereby activating Fe translocation via the bHLH38/39-mediated transcriptional regulation of downstream Fe genes.
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China shencj@hznu.edu.cn whz62@163.com.
authors.forename: Chenjia
authors.initials: C
authors.lastname: Shen
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Life Science and Technology School, Lingnan Normal University, Zhanjiang, Guangdong 524048, China.
authors.forename: Kaidong
authors.initials: K
authors.lastname: Liu
authors.affiliation: Department of Plant Pathology, North Carolina State University, Raleigh, NC 27607, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Guo
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China shencj@hznu.edu.cn whz62@163.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Sun
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China shencj@hznu.edu.cn whz62@163.com.
authors.forename: Huizhong
authors.initials: H
authors.lastname: Wang
mesh_terms: D017360:Arabidopsis / Q000502:physiology*; D020869:Gene Expression Profiling; D007501:Iron / Q000378:metabolism; D000090463:Iron Deficiencies; D010937:Plant Growth Regulators / Q000378:metabolism / Q000502:physiology; D030821:Plants, Genetically Modified; D020156:Salicylic Acid / Q000378:metabolism*; D012639:Seeds / Q000378:metabolism / Q000502:physiology
chemical_list: D010937:Plant Growth Regulators; D007501:Iron; D020156:Salicylic Acid
keywords: Fe deficiency; RNA sequencing; hormones; nutrients; salicylic acid; transcriptome analysis.