Regeneration of Plantago species plants from explants useable for Agrobacterium tumefaciens-mediated transformation

The genus Plantago is worldwide distributed and several of its members contain bioactive metabolites such as iridoids and polysaccharides, having anit-oxidant and anti-inflammatory acitivity and the genus Plantago is therefore used as medicinal plants [1]. There are only few reports on regeneration of Plantago species as well as Agrobacterium tumefaciens-mediated transformation [2]. We here describe regeneration protocols for P. major, media and lanceolata as well as successful genetic transformation of P. lanceolata. Shoots were best regenerated from stem explants with around 54% and 98% efficiency for P. major and P. media, respectively. P. lanceolata was best regenerated from mature leaf explants (60% efficiency). T-DNA transfer was achieved by infiltration or incubation of P. lanceolata mature leaf explants with p9 – 35S-GUS in YNB Medium with acetosyringon (40 mg/L) and antibiotics (spectinomycin + rifampicin). Successful T-DNA-transfer was verified by GUS staining directly after co-cultivation. After 24h pre-culture, 30 min incubation and 9 d co-cultivation all explants showed GUS-stained areas. The established regeneration and transformation protocol now offers a tool to study Plantago species in more detail with regard to natural product synthesis especially iridoids, which is the target pathway we are interested in.

[1] Zhou Q, Lu W, Niu Y, Liu J, Zhang X, Gao B, Akoh CC, Shi H, Yu LL. J Agric Food Chem 2013; 61: 6693 – 6702

[2] Pommerrenig B, Barth I, Niedermeier M, Kopp S, Schmid J, Dwyer RA, McNair RJ, Klebl F, Sauer N. Plant Physiol 2006; 142: 1427 – 1441