Agrobacterium tumefaciens-mediated transformation of Campanula carpatica: factors affecting transformation and regeneration of transgenic shoots

Abstract

An efficient transformation system for Campanula carpatica was developed using Agrobacterium tumefaciens strains LBA4404 (harbouring the plasmid pBI121), and AGL0 (harbouring the plasmid pBEO210). This is the first report on the transformation of C. carpatica. Various factors affecting the transformation efficiency and subsequent regeneration were identified. The age of seedlings from which the explants for transformation studies were taken, and the growth conditions under which the seedlings were grown had a significant influence on the production of transformed shoots. Hypocotyls taken from 12-day-old seedlings grown in the dark were the most productive, with up to 25% of hypocotyls producing transformed shoots. Explants taken from 5-week-old seedlings produced only transformed callus. The medium used for co-cultivation and incubation also had a significant influence on transformation frequency and shoot regeneration. The cultivar "Blue Uniform" was more responsive than "White Uniform". Both bacterial strains and plasmids were equally effective in producing transformed tissue. Transformed shoots were selected on kanamycin medium, and the presence of the uidA and nptII genes in those selected shoots was confirmed by beta-glucuronidase and ELISA analyses, respectively.

Adventitious bud regeneration from leaf explants of Platanus occidentalis L. and genetic stability assessment

“…Prior incubation in the dark is very important process for dedifferentiation and differentiation of P. occidentalis. Incubation in the dark has been reported to increase shoot regeneration in various plant species, such as blueberry (Billings et al 1988), pear (Chevreau et al 1989), apple (Fasolo et al 1989), campanula (Sriskandarajah et al 2004), watermelon (Compton 1999), Zhanhua winter jujube (Gu and Zhang 2005) and quince (Baker and Bhatia 1993). Our results indicated that an incubation period of 7 days in the dark is optimal for shoot regeneration of P. occidentalis (data not presented).…”

High-frequency plant regeneration through adventitious shoot formation in castor (Ricinus communis L.)

“…b (Sriskandarajah et al, 2004). The adventitious shoot regeneration of Zhanhua winter jujube (Z. jujuba) was maximal (76.2% of leaf explants producing shoots) when explants had been incubated in the dark for 20 d (Gu and Zhang, 2005).…”

An Efficient Hairy Root Transformation Method for Common Bean based on Petiole Explants

“…The selection of explants also plays a pivotal role in determining transformation efficiency. Young and tender explants are typically favored for infestation, as reported in several studies (Hadfi and Batschauer, 1994;Liu et al, 2013;Sriskandarajah et al, 2004). In potato, leaf and internode explants from various cultivars were infected with Agrobacterium tumefaciens strain LBA4404, yielding a transformation efficiency of 22% for internode explants and 15% for leaf discs in the Lady Olympia cultivar (Bakhsh, 2020).…”