Improved eco-friendly recombinant Anabaena sp. strain PCC7120 with enhanced nitrogen biofertilizer potential.
Photosynthetic, nitrogen-fixing Anabaena strains are native to tropical paddy fields and contribute to the carbon and nitrogen economy of such soils. Genetic engineering was employed to improve the nitrogen biofertilizer potential of Anabaena sp. strain PCC7120. Constitutive enhanced expression of an additional integrated copy of the hetR gene from a light-inducible promoter elevated HetR protein expression and enhanced functional heterocyst frequency in the recombinant strain. The recombinant strain displayed consistently higher nitrogenase activity than the wild-type strain and appeared to be in homeostasis with compatible modulation of photosynthesis and respiration. The enhanced combined nitrogen availability from the recombinant strain positively catered to the nitrogen demand of rice seedlings in short-term hydroponic experiments and supported better growth. The engineered strain is stable, eco-friendly, and useful for environmental application as nitrogen biofertilizer in paddy fields.
Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
Akhilesh Kumar
AK
Chaurasia
Shree Kumar
SK
Apte
D017033:Anabaena / Q000235:genetics* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005308:Fertilizers; D018628:Gene Dosage; D015870:Gene Expression; D005818:Genetic Engineering; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism*; D009591:Nitrogenase / Q000096:biosynthesis; D012275:Oryza / Q000254:growth & development / Q000382:microbiology; D010084:Oxidation-Reduction; D010788:Photosynthesis; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D005308:Fertilizers; C067403:HetR protein, Bacteria; D009591:Nitrogenase; D009584:Nitrogen