title: Regulation of nonsymbiotic and truncated hemoglobin genes of Lotus japonicus in plant organs and in response to nitric oxide and hormones.
abstract: • In legumes, symbiotic leghemoglobins facilitate oxygen diffusion to the bacteroids, but the roles of nonsymbiotic and truncated hemoglobins are largely unknown. Here the five hemoglobin genes of Lotus japonicus have been functionally characterized to gain insight into their regulatory mechanisms. • Plants were exposed to nitric oxide donors, stressful conditions, and hormones. Gene expression profiling was determined by quantitative PCR, and gene activities were localized using in situ hybridization and promoter-reporter gene fusions. • The LjGLB1-1, LjGLB2, and LjGLB3-1 mRNA expression levels were very high in nodules relative to other plant organs. The expression of these genes was localized in the vascular bundles, cortex, and infected tissue. LjGLB1-1 was the only gene induced by nitric oxide. Cytokinins caused nearly complete inactivation of LjGLB2 and LjGLB3-1 in nodules and induction of LjGLB1-1 in roots. Abscisic acid induced LjGLB1-1 in nodules and LjGLB1-2 and LjGLB2 in roots, whereas polyamines and jasmonic acid induced LjGLB1-1 only in roots. • The enhanced expression of the three types of hemoglobins in nodules, the colocalization of gene activities in nodule and root tissues with high metabolic rates, and their distinct regulatory mechanisms point out complementary roles of hemoglobins and strongly support the hypothesis that LjGLB1-1, LjGLB2, and LjGLB3-1 are required for symbiosis.
authors.affiliation: Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas, Apartado 13034, 50080 Zaragoza, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Bustos-Sanmamed
authors.affiliation: Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas, Apartado 13034, 50080 Zaragoza, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Tovar-Méndez
authors.affiliation: Institut des Sciences du Végétal, CNRS, 1 Avenue de la Terrase, 91198 Gif-sur-Yvette Cedex, France.
authors.forename: Martin
authors.initials: M
authors.lastname: Crespi
authors.affiliation: Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan.
authors.forename: Shusei
authors.initials: S
authors.lastname: Sato
authors.affiliation: Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.affiliation: Departamento de Nutrición Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas, Apartado 13034, 50080 Zaragoza, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Becana
mesh_terms: D001419:Bacteria / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D017343:Genes, Plant; D000070116:Lotus / Q000235:genetics* / Q000378:metabolism; D009569:Nitric Oxide / Q000494:pharmacology*; D010937:Plant Growth Regulators / Q000494:pharmacology*; D018514:Plant Structures / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013559:Symbiosis / Q000235:genetics*; D054793:Truncated Hemoglobins / Q000235:genetics* / Q000378:metabolism
chemical_list: D010937:Plant Growth Regulators; D012333:RNA, Messenger; D054793:Truncated Hemoglobins; D009569:Nitric Oxide