In vitro Regeneration and Agrobacterium-mediated Genetic Transformation of Tomato (Lycopersicon esculentum Mill.)

Abstract

Agrobacterium-mediated genetic transformation system has been developed for two tomato (Lycopersicon esculentum Mill.) varieties, namely Pusa Ruby (PR) and BARI Tomato-3 (BT-3). Prior to the establishment of transformation protocol cotyledonary leaf explants from the two varieties were cultured to obtain genotype independent in vitro regeneration. Healthy multiple shoot regeneration was obtained from the cut ends of cotyledonary leaf segments for both the varieties on MS containing 1.0 mg/l BAP and 0.1 mg/l IAA. The maximum root induction from the regenerated shoots was achieved on half the strength of MS medium supplemented with 0.2 mg/l IAA. The in vitro grown plantlets were successfully transplanted into soil where they flowered and produced fruits identical to those developed by control plants. Transformation ability of cotyledonary leaf explants was tested with Agrobacterium tumefaciens strain LBA4404 harboring binary plasmid pBI121, containing GUS and npt II genes. Transformed cotyledonary leaf explants were found to produce multiple shoots on MS containing 1.0 mg/l BAP and 0.1 mg/l IAA. Selection of the transformed shoots was carried out by gradually increasing the concentration of kanamycin to 200 mg/l since kanamycin resistant gene was used for transformation experiments. Shoots that survived under selection pressure were subjected to rooting. Transformed rooted plantlets were transferred to soil. Stable expression of GUS gene was detected in the various tissues from putatively transformed plantlets using GUS histochemical assay.

Induction of hairy roots in Arnica montana L. by Agrobacterium rhizogenes

“…The hypocotyl and cotyledon segments, petioles and young leaves are the most frequently used explants for Agrobacterium mediated transformation [23,24]. For different transformation trials the shoots induced by organogenesis [25,26] and embryogenic calli [27,28] were also successfully applied. In the present study, leaves from clonally micropropagated plants and from in vitro regenerated plants obtained through callus culture were used as the source of segments.…”

Variation in genotypic responses and biochemical analysis of callus induction in cultivated wheat

“…In vitro regeneration of wheat is possible from different explants such as mature and immature embryos, seeds, endosperm, leaves, shoot bases, and root tips (Sarker and Biswas, 2002). Immature embryo was reported as the best tissue for callus induction and shoot regeneration (Arzani and Mirodjagh, 1999;Sarker and Biswas, 2002); but availability of immature embryo is limited by wheat growing season or requires sophisticated growth chambers. On the other hand, mature seeds of wheat are readily available throughout the year, hence can be used for plant regeneration at any time.…”

Tissue Culture Technology is a Breeding Approach in Wheat: An Overview

“…Callus formation, immature embryo and regeneration of shoot among all explants can produce excellent results (Hou et al, 1997;Arzani and Mirodjagh, 1999;Sarker and Biswas, 2002). Transformation and regeneration in Agro bacterium can be inducted by previously cultured embryos callus and immature wheat embryos (Cheng et al, 1997).…”