title: Ca(2+) -regulated and diurnal rhythm-regulated Na(+) /Ca(2+) exchanger AtNCL affects flowering time and auxin signalling in Arabidopsis.
abstract: Calcium (Ca(2+) ) is vital for plant growth, development, hormone response and adaptation to environmental stresses, yet the mechanisms regulating plant cytosolic Ca(2+) homeostasis are not fully understood. Here, we characterize an Arabidopsis Ca(2+) -regulated Na(+) /Ca(2+) exchanger AtNCL that regulates Ca(2+) and multiple physiological processes. AtNCL was localized to the tonoplast in yeast and plant cells. AtNCL appeared to mediate sodium (Na(+) ) vacuolar sequestration and meanwhile Ca(2+) release. The EF-hand domains within AtNCL regulated Ca(2+) binding and transport of Ca(2+) and Na(+) . Plants with diminished AtNCL expression were more tolerant to high CaCl2 but more sensitive to both NaCl and auxin; heightened expression of AtNCL rendered plants more sensitive to CaCl2 but tolerant to NaCl. AtNCL expression appeared to be regulated by the diurnal rhythm and suppressed by auxin. DR5::GUS expression and root responses to auxin were altered in AtNCL mutants. The auxin-induced suppression of AtNCL was attenuated in SLR/IAA14 and ARF6/8 mutants. The mutants with altered AtNCL expression also altered flowering time and FT and CO expression; FT may mediate AtNCL-regulated flowering time change. Therefore, AtNCL is a vacuolar Ca(2+) -regulated Na(+) /Ca(2+) exchanger that regulates auxin responses and flowering time.
authors: College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430075, China.
authors: Penghui
authors: P
authors: Li
authors: College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430075, China.
authors: Gaoyang
authors: G
authors: Zhang
authors: Children's Nutrition Research Center, USDA/ARS, Baylor College of Medicine, Houston, TX, 77030, USA.
authors: Naomi
authors: N
authors: Gonzales
authors: College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430075, China.|Children's Nutrition Research Center, USDA/ARS, Baylor College of Medicine, Houston, TX, 77030, USA.
authors: Yingqing
authors: Y
authors: Guo
authors: College of Life Science and technology, Huazhong Agricultural University, Wuhan, 430075, China.
authors: Honghong
authors: H
authors: Hu
authors: Department of Horticulture, Forestry and Recreation Resources, Kansas State University, Manhattan, KS, 66506, USA.
authors: Sunghun
authors: S
authors: Park
authors: College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430075, China.|Children's Nutrition Research Center, USDA/ARS, Baylor College of Medicine, Houston, TX, 77030, USA.
authors: Jian
authors: J
authors: Zhao
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002412:Cations; D002940:Circadian Rhythm; D020832:EF Hand Motifs; D035264:Flowers / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006706:Homeostasis; D007210:Indoleacetic Acids / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D059828:Plant Cells / Q000378:metabolism; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D015398:Signal Transduction; D012964:Sodium / Q000378:metabolism; D019831:Sodium-Calcium Exchanger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014617:Vacuoles / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D002412:Cations; D007210:Indoleacetic Acids; C000611604:NCL protein, Arabidopsis; D019831:Sodium-Calcium Exchanger; D049452:Green Fluorescent Proteins; D012964:Sodium; D002118:Calcium
keywords: Na+/Ca2+ homeostasis; auxin response; flowering time; vacuole