title: Agrobacterium-mediated genetic transformation of tea leaf explants: effects of counteracting bactericidity of leaf polyphenols without loss of bacterial virulence.
abstract: Tea is one of the major crops in Asia and Africa, and its improvement by genetic modification is important for economy of many tea-producing regions. Although somatic embryos derived from cotyledon explants have been transformed with Agrobacterium, the leaves of several commercially important tea cultivars have remained recalcitrant to transformation, largely due to bactericidal effect of polyphenols that are exuded by tea leaves in vitro. Moreover, the commonly used polyphenol adsorbents and antioxidants cannot overcome this problem. Leaf explants, however, are more desirable than cotyledon-derived somatic embryos, especially when it is necessary to further improve a selected elite and also retain its superior traits. Thus, we developed a procedure for Agrobacterium-mediated genetic transformation of tea leaf explants which is based on the presence of L-glutamine in the co-cultivation medium. We then showed that the transformation process is facilitated via a protective action of L-glutamine against bactericidal effects of leaf polyphenols without affecting the bacterial virulence (vir) gene expression.
authors.affiliation: Institute of Himalayan Bioresource Technology, Palampur, 176016, Himachal Pradesh, India.
authors.forename: Indra
authors.initials: I
authors.lastname: Sandal
authors.forename: Uksha
authors.initials: U
authors.lastname: Saini
authors.forename: Benoît
authors.initials: B
authors.lastname: Lacroix
authors.forename: Amita
authors.initials: A
authors.lastname: Bhattacharya
authors.forename: Paramvir Singh
authors.initials: PS
authors.lastname: Ahuja
authors.forename: Vitaly
authors.initials: V
authors.lastname: Citovsky
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism*; D018929:Cell Culture Techniques; D003470:Culture Media / Q000737:chemistry; D005419:Flavonoids / Q000378:metabolism*; D005798:Genes, Bacterial; D005973:Glutamine / Q000494:pharmacology; D010636:Phenols / Q000378:metabolism*; D018515:Plant Leaves / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D030821:Plants, Genetically Modified; D059808:Polyphenols; D012231:Rhizobium / Q000235:genetics* / Q000472:pathogenicity; D013662:Tea / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D014170:Transformation, Genetic / Q000187:drug effects; D019076:Transgenes; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D013662:Tea; D037521:Virulence Factors; D005973:Glutamine