title: Arabidopsis NRT1.5 Mediates the Suppression of Nitrate Starvation-Induced Leaf Senescence by Modulating Foliar Potassium Level.
abstract: Nitrogen deficiency induces leaf senescence. However, whether or how nitrate might affect this process remains to be investigated. Here, we report an interesting finding that nitrate-instead of nitrogen-starvation induced early leaf senescence in nrt1.5 mutant, and present genetic and physiological data demonstrating that nitrate starvation-induced leaf senescence is suppressed by NRT1.5. NRT1.5 suppresses the senescence process dependent on its function from roots, but not the nitrate transport function. Further analyses using nrt1.5 single and nia1 nia2 nrt1.5-4 triple mutant showed a negative correlation between nitrate concentration and senescence rate in leaves. Moreover, when exposed to nitrate starvation, foliar potassium level decreased in nrt1.5, but adding potassium could essentially restore the early leaf senescence phenotype of nrt1.5 plants. Nitrate starvation also downregulated the expression of HAK5, RAP2.11, and ANN1 in nrt1.5 roots, and appeared to alter potassium level in xylem sap from nrt1.5. These data suggest that NRT1.5 likely perceives nitrate starvation-derived signals to prevent leaf senescence by facilitating foliar potassium accumulation.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, National Center for Plant Gene Research (Shanghai), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
authors.forename: Shuan
authors.initials: S
authors.lastname: Meng
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, National Center for Plant Gene Research (Shanghai), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
authors.forename: Jia-Shi
authors.initials: JS
authors.lastname: Peng
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, National Center for Plant Gene Research (Shanghai), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
authors.forename: Ya-Ni
authors.initials: YN
authors.lastname: He
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, National Center for Plant Gene Research (Shanghai), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
authors.forename: Guo-Bin
authors.initials: GB
authors.lastname: Zhang
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, National Center for Plant Gene Research (Shanghai), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
authors.forename: Hong-Ying
authors.initials: HY
authors.lastname: Yi
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, National Center for Plant Gene Research (Shanghai), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China.
authors.forename: Yan-Lei
authors.initials: YL
authors.lastname: Fu
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, National Center for Plant Gene Research (Shanghai), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China. Electronic address: jmgong@sibs.ac.cn.
authors.forename: Ji-Ming
authors.initials: JM
authors.lastname: Gong
mesh_terms: D027321:Anion Transport Proteins / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D009154:Mutation; D009566:Nitrates / Q000378:metabolism*; D018515:Plant Leaves / Q000254:growth & development* / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D013997:Time Factors; D052584:Xylem / Q000378:metabolism
chemical_list: D027321:Anion Transport Proteins; D029681:Arabidopsis Proteins; C539716:NRT1.5 protein, Arabidopsis; D009566:Nitrates; D011188:Potassium
keywords: Leaf Senescence; NRT1.5; Nitrate Starvation; Potassium