@article { ISI:000308331200002,
	title = {Enhanced tolerance of transgenic grapevines expressing chitinase and beta-1,3-glucanase genes to downy mildew},
	journal = {Plant Cell Tissue and Organ Culture},
	volume = {111},
	number = {1},
	year = {2012},
	month = {OCT},
	pages = {15-28},
	publisher = {SPRINGER},
	address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS},
	abstract = {<p>An Agrobacterium-mediated transformation protocol for grapevine cv. Crimson Seedless using sonication and anti-necrotic agents has been optimized, and transgenic lines carrying wheat chitinase and beta-1,3-glucanase genes have exhibited enhanced tolerance to downy mildew incited by Plasmopara viticola. cDNA clones encoding chitinase and beta-1,3-glucanase have been isolated from a cDNA library, constructed from scab-infected Sumai-3 wheat, and introduced into a plant cloning vector to generate the plasmids pCAMBAR.chi.11 and pCAMBAR.638. Embryogenic cultures, established from in vitro-derived leaves, of Crimson Seedless were used as explants for Agrobacterium tumefaciens-mediated transformation studies. Sonication of somatic embryos in a bacterial suspension of A. tumefaciens and incorporation of anti-necrotic agents in the co-cultivation medium significantly enhanced transformation efficiency. Transformation efficiency of embryos with either chitinase or beta-1,3-glucanase gene was highest when embryos were suspended in a bacterial cell suspension at 0.5 OD600 and sonicated for 2 or 3 s at 60 kHz. Transformation efficiency with chitinase was highest on incorporation of 2 or 3 mg l(-1) phenylalanine, 1 or 2 mg l(-1) silver nitrate or 400 mg l(-1) l-cysteine in co-cultivation medium while incorporation of 20 mg l(-1) sodium thiosulphate produced highest transformation efficiency with beta-1,3-glucanase. Confirmed transgenic grapevine lines harboring anti-fungal genes exhibited higher levels of chitinase and beta-1,3-glucanase transcripts as well as enzymatic activities. Moreover, transgenic lines showed enhanced tolerance to P. viticola infection following detached leaf assays.</p>},
	keywords = {Agrobacterium tumefaciens, Anti-oxidants, Downy mildew tolerance, Grapevine, Sonication},
	issn = {0167-6857},
	doi = {10.1007/s11240-012-0166-1},
	author = {Nookaraju, Akula and Agrawal, Dinesh C.}
}
@article { ISI:000358167700015,
	title = {Overexpression of squalene synthase in withania somnifera leads to enhanced withanolide biosynthesis},
	journal = {Plant Cell Tissue and Organ Culture},
	volume = {122},
	number = {2},
	year = {2015},
	month = {AUG},
	pages = {409-420},
	publisher = {SPRINGER},
	address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS},
	abstract = {<p>Genetic engineering of secondary metabolic pathways is an emerging area of research for production and improvement of natural products in plant biotechnology. Here, we describe a systematic approach to manipulate a key regulatory step of isoprenoid biosynthetic pathway in Withania somnifera to study its effect on withanolide production. We generated T-0 W. somnifera plants overexpressing squalene synthase (WsSQS) by Agrobacterium tumefaciens mediated transformation, which were analyzed by Gus biochemical assay and PCR of hygromycin phosphotransferase (hptII) and WsSQS. qRT-PCR analyses of various transformed tissues indicated 2-5 fold increase in WsSQS transcripts in both T-0 and T-1 generations. The tissue specific protein expression studies revealed 2-3 fold increase in WsSQS, which was further confirmed by enzyme activity. These observations were corroborated with the 1.5-2 fold increase in total withanolide content of the transformed tissues. However, in leaf tissue, the levels of Withaferin A and Withanolide A increased significantly up to 4-4.5 fold. These findings demonstrate genetic engineering of isoprenoid pathway in W. somnifera resulting in enhanced production of withanolides, and also provide insights into such metabolic pathways for their manipulation to improve the pharmacological content of different medicinally important plants.</p>},
	keywords = {Agrobacterium tumefaciens, Solanaceae, Squalene synthase, Withania somnifera, Withanolides},
	issn = {0167-6857},
	doi = {10.1007/s11240-015-0778-3},
	author = {Patel, Neha and Patel, Parth and Kendurkar, Shuchishweta V. and Thulasiram, Hirekodathakallu V. and Khan, Bashir Mohammad}
}
