Overexpression of citrate operon in Herbaspirillum seropedicae Z67 enhances organic acid secretion, mineral phosphate solubilization and growth promotion of Oryza sativa
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Background and aims
Herbaspirillum seropedicae Z67, nitrogen fixing endophyte, significantly promotes the growth of cereals. Organic acid secreting nitrogen fixing rhizobacteria have better plant growth promotion abilities due to mineral phosphate solubilization.
Plasmids pAB7, pJNK3 and pJNK4 containing Escherichia coli cs (gltA), NADH insensitive cs (gltA1), and citrate operon consisting of gltA1 gene along with Salmonella typhimurium Na+ dependent citrate transporter (citC) gene under constitutive lac promoter were constructed in broad host range plasmid pUCPM18-Kmr. The plasmid transformants of H. seropedicae Z67 were obtained by electroporation.
Hs (pAB7) and Hs (pJNK3) had increased CS activity but citric acid secretion was not significant. Hs (pJNK3) secreted 45 mM acetic acid while Hs (pJNK4) secreted 2.7 mM citric and 51 mM acetic acids. Hs (pJNK3) and Hs (pJNK4) released 80 μM and 110 μM amount of P from rock phosphate, respectively, in buffered medium under both aerobic and micro aerobic conditions. These transformants showed better plant growth promoting factors. Upon inoculation to rice plants (Gujarat – 17), increase of Fresh weight, Dry weight N, P and K content was observed.
Thus the study demonstrates that artificial citrate operon in H. seropedicae Z67 enhances phosphate solubilization and plant growth promotion abilities.
KeywordsCitrate synthase Citrate secretion Citrate transporter Mineral phosphate solubilization Rice
- Hester KL, Lehman J, Najar F, Song L, Roe BA, MacGregor CH, Hager PW, Phibbs PV Jr, Sokatch JR (2000) Crc is involved in catabolite repression control of the bkd operons of Pseudomonas putida and Pseudomonas aeruginosa. J Bacteriol 182:1144–1149Google Scholar
- Pedrosa FO, Monteiro RA, Wassem R, Cruz LM, Ayub RA, Colauto NB, Fernandez MA, Fungaro MHP, Grisard EC, Hungria M, Madeira HMF, Nodari RO, Osaku CA, Petzl-Erler ML, Terenzi H, Vieira LGE, Almeida MIM, Alves LR, Arantes OMN, Balsanelli E, Barcellos FG, Baura VA, Binde DR, Campo RJ, Chubatsu LS, Chueire LMO, Ciferri RR, Correa LC, da Conceicao Silva JL, Dabul ANG, Dambros BP, Faoro H, Favetti A, Friedermann G, Furlaneto MC, Gasques LS, Gimenes CCT, Gioppo NMR, Glienke-Blanco C, Godoy LP, Guerra MP, Karp S, Kava-Cordeiro V, Margarido VP, Mathioni SM, Menck-Soares MA, Murace NK, Nicolas MF, Oliveira CEC, Pagnan NAB, Pamphile JA, Patussi EV, Pereira LFP, Pereira-Ferrari L, Pinto FGS, Precoma C, Prioli AJ, Prioli SMAP, Raittz RT, Ramos HJO, Ribeiro EMSF, Rigo LU, Rocha CLMSC, Rocha SN, Santos K, Satori D, Silva AG, Simao RCG, Soares MAM, Souza EM, Steffens MBR, Steindel M, Tadra-Sfeir MZ, Takahashi EK, Torres RA, Valle JS, Vernal JI, Vilas-Boas LA, Watanabe MAE, Weiss VA, Yates MA, Souza EM (2011) Genome of Herbaspirillum seropedicae strain SmR1, a specialized diazotrophic endophyte of tropical grasses. PLoS Genet 7:5CrossRefGoogle Scholar
- Pikovskaya RI (1948) Mobilization of phosphorus in soil in connection with vital activity of some microbial species. Mikrobiol 17:362–370Google Scholar
- Radwan TSD, Massena MKZ, Reis V (2004) Effect of inoculation of Azospirillum and Herbaspirillum in production of indole compounds in seedlings of maize and rice. Pesquia Agrop Bras Brasilia Braz 39:987–994Google Scholar
- Sambrook J, Fritch EF, Maniatis T (2001) Molecular cloning: a laboratory manual, 3rd edn. Cold Spring Harbor Laboratory Press, Cold Spring HarborGoogle Scholar
- Srivastava S, Kausalya MT, Archana G, Rupela OP, Naresh Kumar G (2006) Efficacy of organic acid secreting bacteria in solubilization of rock phosphate in acidic alfisols. Dev Plant Soil Sci 102:117–124Google Scholar
- Unge A, Tombolini R, Davey ME, de Bruijn FJ, Jansson JK (1996) GFP as a marker gene. In: Akkermans ADL, Van Elsas JD, de Bruijn FJ (eds) Molecular Microbial Ecology Manual Section 6.1.13. Academic Publishers, Dordrecht, pp 1–16Google Scholar
- Valverde A, Burgos A, Fiscella T, Rivas R, Velazquez E, Rodriguez-Barrueco C, Cervantes E, Manuel C, Jose-Mariano I (2007) Differential effects of coinoculations with Pseudomonas jessenii PS06 (a phosphate-solubilizing bacterium) and Mesorhizobium ciceri C-2/2 strains on the growth and seed yield of chickpea under greenhouse and field conditions. Dev Plant Soil Sci 102:43–50Google Scholar