02545nas a2200217   4500008004100000022001400041245011400055210006900169260007400238300001000312490000800322520171700330653003002047653001802077653002702095653001402122653001502136100002102151700002402172856013102196       2012                        eng d  a0167-685700aEnhanced tolerance of transgenic grapevines expressing chitinase and beta-1,3-glucanase genes to downy mildew0 aEnhanced tolerance of transgenic grapevines expressing chitinase  aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcOCT  a15-280 v1113 a<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>10aAgrobacterium tumefaciens10aAnti-oxidants10aDowny mildew tolerance10aGrapevine10aSonication1 aNookaraju, Akula1 aAgrawal, Dinesh, C.  uhttps://library.ncl.res.in/content/enhanced-tolerance-transgenic-grapevines-expressing-chitinase-and-beta-13-glucanase-genes-002312nas a2200253   4500008004100000022001400041245010500055210006900160260007400229300001200303490000800315520137900323653003001702653001501732653002201747653002301769653001701792100001601809700001701825700003201842700003701874700002701911856012001938       2015                        eng d  a0167-685700aOverexpression of squalene synthase in withania somnifera leads to enhanced withanolide biosynthesis0 aOverexpression of squalene synthase in withania somnifera leads   aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcAUG  a409-4200 v1223 a<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>10aAgrobacterium tumefaciens10aSolanaceae10aSqualene synthase10aWithania somnifera10aWithanolides1 aPatel, Neha1 aPatel, Parth1 aKendurkar, Shuchishweta, V.1 aThulasiram, Hirekodathakallu, V.1 aKhan, Bashir, Mohammad  uhttps://library.ncl.res.in/content/overexpression-squalene-synthase-withania-somnifera-leads-enhanced-withanolide-0