title: Putrescine Alleviates Iron Deficiency via NO-Dependent Reutilization of Root Cell-Wall Fe in Arabidopsis.
abstract: Plants challenged with abiotic stress show enhanced polyamines levels. Here, we show that the polyamine putrescine (Put) plays an important role to alleviate Fe deficiency. The adc2-1 mutant, which is defective in Put biosynthesis, was hypersensitive to Fe deficiency compared with wild type (Col-1 of Arabidopsis [Arabidopsis thaliana]). Exogenous Put decreased the Fe bound to root cell wall, especially to hemicellulose, and increased root and shoot soluble Fe content, thus alleviating the Fe deficiency-induced chlorosis. Intriguingly, exogenous Put induced the accumulation of nitric oxide (NO) under both Fe-sufficient (+Fe) and Fe-deficient (-Fe) conditions, although the ferric-chelate reductase (FCR) activity and the expression of genes related to Fe uptake were induced only under -Fe treatment. The alleviation of Fe deficiency by Put was diminished in the hemicellulose-level decreased mutant-xth31 and in the noa1 and nia1nia2 mutants, in which the endogenous NO levels are reduced, indicating that both NO and hemicellulose are involved in Put-mediated alleviation of Fe deficiency. However, the FCR activity and the expression of genes related to Fe uptake were still up-regulated under -Fe+Put treatment compared with -Fe treatment in xth31, and Put-induced cell wall Fe remobilization was abolished in noa1 and nia1nia2, indicating that Put-regulated cell wall Fe reutilization is dependent on NO. From our results, we conclude that Put is involved in the remobilization of Fe from root cell wall hemicellulose in a process dependent on NO accumulation under Fe-deficient condition in Arabidopsis.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China (X.F.Z., B.W., W.F.S., R.F.S.); University of Chinese Academy of Sciences, Beijing 100049, China (B.W., W.F.S.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China (S.J.Z.).
authors.forename: Xiao Fang
authors.initials: XF
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China (X.F.Z., B.W., W.F.S., R.F.S.); University of Chinese Academy of Sciences, Beijing 100049, China (B.W., W.F.S.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China (S.J.Z.).
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China (X.F.Z., B.W., W.F.S., R.F.S.); University of Chinese Academy of Sciences, Beijing 100049, China (B.W., W.F.S.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China (S.J.Z.).
authors.forename: Wen Feng
authors.initials: WF
authors.lastname: Song
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China (X.F.Z., B.W., W.F.S., R.F.S.); University of Chinese Academy of Sciences, Beijing 100049, China (B.W., W.F.S.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China (S.J.Z.).
authors.forename: Shao Jian
authors.initials: SJ
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China (X.F.Z., B.W., W.F.S., R.F.S.); University of Chinese Academy of Sciences, Beijing 100049, China (B.W., W.F.S.); andState Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China (S.J.Z.) rfshen@issas.ac.cn.
authors.forename: Ren Fang
authors.initials: RF
authors.lastname: Shen
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D002262:Carboxy-Lyases / Q000235:genetics / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism*; D038181:FMN Reductase / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D007501:Iron / Q000378:metabolism*; D009154:Mutation; D009569:Nitric Oxide / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism; D011700:Putrescine / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D002262:Carboxy-Lyases; D027682:Cation Transport Proteins; D038181:FMN Reductase; D007501:Iron; D009569:Nitric Oxide; D011134:Polysaccharides; D011700:Putrescine; C501411:FIT1 protein, Arabidopsis; C099651:IRT1 protein, Arabidopsis; C007916:hemicellulose; C023903:ferric citrate iron reductase; C019722:arginine decarboxylase