title: Characterization of a symbiotic, heterocystous, N2-fixing cyanobacterium fromCycas coralloid roots.
abstract: A symbiotic, heterocystous, N2-fixing blue-green alga, isolated from the coralloid roots of a xerophytic plant,Cycas revoluta, grew best in liquid medium supplemented with 4 mM NO 3 (-) . Morphologically, the isolated alga was identical to that of the natural endophyte but the cell size had decreased markedly. The alga was heterotrophic. Intact coralloid roots had nearly 4 to 5 times more nitrogenase activity compared with natural- and laboratory-grown agla but nitrate reductase was inducible in both the forms. Plasmid(s) were found in both algal forms.
authors.affiliation: Department of Biochemistry, College of Basic Sciences and Humanities, G.B. Pant University of Agriculture and Technology, 263 145, Pantnagar, Uttar Pradesh, India.
authors.forename: A
authors.initials: A
authors.lastname: Sharma
authors.forename: D P
authors.initials: DP
authors.lastname: Mishra
authors.forename: A
authors.initials: A
authors.lastname: Kumar