Studying early nodulin gene ENOD40 expression and induction by nodulation factor and cytokinin in transgenic alfalfa

• Published in: Plant physiology (Bethesda) Vol. 116; no. 1; pp. 53 - 68
• Main Authors: Fang, Y, Hirsch, A.M
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01.01.1998
• Subjects: 6-BENZILADENINA; 6-BENZYLADENINE; Agronomy. Soil science and plant productions; Alfalfa; ANATOMIA DE LA PLANTA; ANATOMIE VEGETALE; Bacterial Proteins - physiology; Base Sequence; Biological and medical sciences; Cytokinins; Cytokinins - physiology; DEVELOPMENTAL STAGES; Economic plant physiology; ETAPAS DE DESARROLLO; EXPRESION GENICA; EXPRESSION DES GENES; FORMATION DE NODOSITES; Fundamental and applied biological sciences. Psychology; GENE; GENE EXPRESSION; Gene Expression Regulation, Plant; GENES; Genes, Plant; Genes, Reporter; GENETIC REGULATION; GENETICA; GENETICS; GENETIQUE; Genomic Library; LOCALIZATION; MEDICAGO SATIVA; Medicago sativa - genetics; Medicago sativa - microbiology; Medicago sativa - physiology; MOLECULAR SEQUENCE DATA; NODOSITE RACINAIRE; NODULACION; Nodulation; Nodules; NUCLEOTIDE SEQUENCE; NUDOSIDADES RADICULARES; Parasitism and symbiosis; PLANT ANATOMY; Plant physiology and development; Plant Proteins - biosynthesis; Plant Proteins - genetics; Plant roots; Plant-Microbe and Plant-Insect Interactions; PLANTAS TRANSGENICAS; PLANTE TRANSGENIQUE; Plants; Plants, Genetically Modified; Promoter regions; Promoter Regions, Genetic; PROMOTERS; Recombinant Fusion Proteins - biosynthesis; REPORTER GENES; RHIZOBIUM MELILOTI; RNA, Long Noncoding; RNA, Untranslated - physiology; ROOT NODULATION; ROOT NODULES; SECUENCIA NUCLEOTIDICA; Sequence Alignment; Sequence Homology, Nucleic Acid; SEQUENCE NUCLEOTIDIQUE; SIMBIOSIS; Sinorhizobium meliloti - physiology; STADE DE DEVELOPPEMENT; SYMBIOSE; SYMBIOSIS; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...); TRANSCRIPCION; TRANSCRIPTION; TRANSGENIC PLANTS; Symbiosis; Symbionte; Rhizobium meliloti; Transcription; Medicago sativa; Tissue specificity; Plant nodule; Gene expression; Cytokinin; Protein; Inoculation; Regulation(control); Leguminosae; Dicotyledones; Angiospermae; Development; Bacteria; Spermatophyta; Transgenic plant; Fodder crop; Rhizobiaceae; Pretreatment
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.116.1.53

ENOD40, an early nodulin gene, is expressed following inoculation with Rhizobium meliloti or by adding R. meliloti-produced nodulation (Nod) factors or the plant hormone cytokinin to uninoculated roots. We isolated two MsENOD40 clones, designated MsENOD40-1 and MsENOD40-2, with distinct promoters from an alfalfa (Medicago sativa cv Chief) genomic library. The promoters were fused to the reporter gene uidA (gus), and the constructs were introduced into alfalfa. We observed that the MsENOD40-1 construct was expressed almost exclusively under symbiotic conditions. The MsENOD40-2 construct was transcribed under both symbiotic and nonsymbiotic conditions and in nonnodular and nodular tissues. Both MsENOD40 promoter-gus constructs were similarly expressed as nodules developed, and both were expressed in roots treated with 6-benzylaminopurine or purified Nod factor. However, no blue color was detected in nodule-like structures induced by the auxin transport inhibitor N-1-(naphthyl)phthalamic acid on roots of plants containing the MsENOD40-1 promoter construct, whereas pseudonodules from plants containing the MsENOD40-2 promoter construct stained blue. A 616-bp region at the distal 5' end of the promoter is important for proper spatial expression of MsENOD40 in nodules and also for Nod-factor and cytokinin-induced expression