Indian Journal of Science and Technology http://www.indjst.org Vol.1 No 7 (Dec. 2008) iSee category: Research article “Cyanobacterial elicitor” by Poornasri et al. Indian Society for Education and Environment Indian J.Sci.Technol. 1 Effect of cyanobacterial elicitor on neem cell suspension cultures B. Poornasri Devi, A. Vimala, Isha Sai and S. Chandra * Dept. of Biosciences, Sri Sathya Sai University, Anantapur Campus, Anantapur-5150 001, A.P., India *P.G. Dept. of Botany, Queen Mary's College, Chennai 600004,T.N. b.psridevi@yahoo.com; laks1956@yahoo.co.in Abstract: The present study aimed to elucidate the effect of cyanobacterial elicitor derived from Anabaena sp. and Nostoc carneum on neem cell suspensions evolved from superior callus lines of Azadirachta indica A. Juss elite KN-1 accession with 12.88 mg/gm azadirachtin in its seed. Neem cell suspension cultures maintained in Murashige and Skoog liquid medium were treated with 265 cells/ml and 530 cells/ml homogenate of the elicitor on the third day. Growth of neem callus in terms of biomass revealed 5 fold enhancements when treated with 530 cells/ml elicitor on tenth day in callus line-1. In callus line-2 the log phase extended till tenth day recording a 6 fold increase with 265 cells/ml elicitor concentration. The type of callus line and concentration of the elicitor influence the biomass growth of neem callus in suspension culture. Enhanced azadirachtin production was achieved by algal elicitor treatment (as confirmed by HPLC analysis) and this study makes a step forward towards industrial manufacturing of the neem alkaloid. Keywords: Anabaena sp., Nostoc carneum, Neem, Azadirachtin, Elicitor, Suspension Culture. Introduction Secondary metabolites such as alkaloids, flavanoids, glycosides, oils, tannins, resins are isolated from wild or cultivated plants because their chemical synthesis is economically infeasible. Plant cells show physiological and morphological responses to microbial, physical or chemical factors which are known as 'elicitors'. Elicitation is a process of induced or enhanced synthesis of secondary metabolites by the plants to ensure their survival persistence and competitiveness. Elicitors are abiotic and biotic, or on their basis of 'origin' like exogenous elicitors and endogenous elicitors. Abiotic elicitors are the substances of non- biological origin, i.e. inorganic salts and physical factors acting as elicitors like Cu 2+ and Cd 2+ ions, Ca 2+ and high pH, where as biotic elicitors are substances of biological origin including polysaccharides derived from plant cell walls (pectin or cellulose) and microorganisms (chitin or glucans and glycol proteins or G-proteins or intercellular proteins). Exogenous elicitors are substances originated outside the cell like polysaccharides, polyamines and fatty acids, where as endogenous elicitors are substances originated inside the cell (Namdeo, 2007). Elicitation of cell cultures with biotic elicitor and signal compounds has been recognized as an important strategy for enhancement of secondary metabolites (Savitha et al., 2006). The enhanced production of secondary metabolites from plant cell cultures through elicitation has opened up a new area of research which could have important economical benefits for pharmaceutical industry. Neem (Azadirachta indica A. Juss Family Meliaceae) has spread to many parts of the world in the tropical and subtropical regions where there is no frost. Various parts of the tree have been in use for several millennia for medicinal, pharmaceutical and agricultural purposes. Azadirachtin, an important bio-pesticide is one of the most active principles obtained from the neem seeds. In order to overcome the difficulties concerning variation in its source, availability, genetic stability and maintenance of purity, in-vitro production (Prakash et al., 2006; Sujanya et al., 2008) through tissue culture techniques is considered to be suitable alternative. Biotic elicitors of fungal origin revealed to be effective on growth as well as the production of azadirachtin in neem cell suspension cultures. Since there is only a scanty reports regarding algal/cyanobacterial elicitors, the present investigation on the effect of cyanobacterial elicitor on neem cell suspension cultures was carried out to understand the biochemical responses of the plant cells when challenged by the elicitor. The present study investigated the positive role of cyanobacterial elicitors (Anabaena sp. and Nostoc carneum) on the biomass and its protein content of neem cell suspensions and the efficiency of elicitor to enhance the production of azadirachtin. Material and Methods Experimental material Elite neem accessions KN1 with high azadirachtin (AZ) 12.88 mg/g, in its seed was identified after an extensive survey of Anantapur District, Andhra Pradesh, India from the provenance of Karnatakanagepalli. Surface sterilization of explants The in-vivo explants such as stems, immature embryos were washed with running water and dettol for 5 minutes and further rinsed with 5% Extran MA 02 for 5 minutes. It is followed by several washes in running tap water for 30 - 45