title: The cloned 1-aminocyclopropane-1-carboxylate (ACC) deaminase gene from Sinorhizobium sp. strain BL3 in Rhizobium sp. strain TAL1145 promotes nodulation and growth of Leucaena leucocephala.
abstract: The objective of this study was to determine the role of 1-aminocyclopropane-1-carboxylate (ACC) deaminase of symbionts in nodulation and growth of Leucaena leucocephala. The acdS genes encoding ACC deaminase were cloned from Rhizobium sp. strain TAL1145 and Sinorhizobium sp. BL3 in multicopy plasmids, and transferred to TAL1145. The BL3-acdS gene greatly enhanced ACC deaminase activity in TAL1145 compared to the native acdS gene. The transconjugants of TAL1145 containing the native or BL3 acdS gene could grow in minimal media containing 1.5mM ACC, whereas BL3 could tolerate up to 3mM ACC. The TAL1145 acdS gene was inducible by mimosine and not by ACC, while the BL3 acdS gene was highly inducible by ACC and not by mimosine. The transconjugants of TAL1145 containing the native- and BL3-acdS genes formed nodules with greater number and sizes, and produced higher root mass on L. leucocephala than by TAL1145. This study shows that the introduction of multiple copies of the acdS gene increased ACC deaminase activities of TAL1145 and enhanced its symbiotic efficiency on L. leucocephala.
authors.affiliation: Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East-West Road, Honolulu, HI 96822, USA.
authors.forename: Panlada
authors.initials: P
authors.lastname: Tittabutr
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Awaya
authors.forename: Qing X
authors.initials: QX
authors.lastname: Li
authors.forename: Dulal
authors.initials: D
authors.lastname: Borthakur
mesh_terms: D018533:Biomass; D019755:Carbon-Carbon Lyases / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004790:Enzyme Induction; D007887:Fabaceae / Q000254:growth & development* / Q000382:microbiology*; D018628:Gene Dosage; D023061:Gene Order; D008898:Mimosine / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D018517:Plant Roots / Q000254:growth & development / Q000382:microbiology; D010957:Plasmids; D012231:Rhizobium / Q000201:enzymology* / Q000235:genetics; D017422:Sequence Analysis, DNA; D020579:Sinorhizobium / Q000201:enzymology* / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D008898:Mimosine; C033634:1-aminocyclopropane-1-carboxylate deaminase; D019755:Carbon-Carbon Lyases