title: Boron deficiency increases the levels of cytosolic Ca(2+) and expression of Ca(2+)-related genes in Arabidopsis thaliana roots.
abstract: Boron (B) deficiency affects the expressions of genes involved in major physiological processes. However, signal transduction pathway through which plants are able to sense and transmit B-deprivation signal to the nucleus is unknown. The aim of this work was to research in Arabidopsis thaliana roots whether the short-term B deficiency affects cytosolic Ca(2+) levels ([Ca(2+)]cyt) as well as expression of genes involved in Ca(2+) signaling. To visualize in vivo changes in root [Ca(2+)]cyt, Arabidopsis seedlings expressing Yellow Cameleon (YC) 3.6 were grown in a nutrient solution supplemented with 2 μM B and then transferred to a B-free medium for 24 h. Root [Ca(2+)]cyt was clearly higher in B-deficient seedlings upon 6 and 24 h of B treatments when compared to controls. Transcriptome analyses showed that transcript levels of Ca(2+) signaling-related genes were affected by B deprivation. Interestingly, Ca(2+) channel (CNGC19, cyclic nucleotide-gated ion channel) gene was strongly upregulated as early as 6 h after B deficiency. Expression levels of Ca(2+) transporter (ACA, autoinhibited Ca(2+)-ATPase; CAX, cation exchanger) genes increased when seedlings were subjected to B deficiency. Gene expressions of calmodulin-like proteins (CMLs) and Ca(2+)-dependent protein kinases (CPKs) were also overexpressed upon exposure to B starvation. Our results suggest that B deficiency causes early responses in the expression of CNGC19 Ca(2+)-influx channel, ACA- and CAX-efflux, and Ca(2+) sensor genes to regulate Ca(2+) homeostasis. It is the first time that changes in the levels of in vivo cytosolic Ca(2+) and expression of Ca(2+) channel/transporter genes are related with short-term B deficiency in Arabidopsis roots.
authors: Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, E-41013 Sevilla, Spain. cquipan@upo.es
authors: Carlos
authors: C
authors: Quiles-Pando
authors: Jesús
authors: J
authors: Rexach
authors: M Teresa
authors: MT
authors: Navarro-Gochicoa
authors: Juan J
authors: JJ
authors: Camacho-Cristóbal
authors: M Begoña
authors: MB
authors: Herrera-Rodríguez
authors: Agustín
authors: A
authors: González-Fontes
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001895:Boron / Q000172:deficiency*; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D001895:Boron; D002118:Calcium