In vitro regeneration and optimization of conditions for Agrobacterium mediated transformation in jute, Corchorus capsularis

Abstract

Jute is a crop of commercial importance that is widely cultivated for its bast fiber production but susceptible to many diseases that results in major economic loss. New genes can be introduced into this plant through Agrobacterium mediated genetic transformation for its genetic improvement, which is dependent on the availability of suitable in vitro techniques. An efficient regeneration system has been developed for in vitro culture of jute (Corchorus capsularis) from the distal cut ends of cotyledonary petioles. High frequency shoot regeneration was obtained on Murashige and Skoog (MS) nutrient agar medium supplemented with 0.5 mg/l NAA, 0.5 mg/l BAP and 36 g/l sucrose. On transfer to soil, the regenerated plantlets survived and appeared to be morphologically similar to the normal seed-grown plants. They developed pods and set fertile seeds. Histological analysis revealed de novo origin of shoot buds in the in vitro cultured cotyledonary petioles. Parameters affecting transformation were optimized by assaying GUS activity in these regenerable tissues after cocultivation with Agrobacteria. These tissues appear to be susceptible for infection and transformation by Agrobacterium carrying uid (GUS INT) and nptII genes, as well as shoot multiplication. The cells at the cut end of the petioles were found competent to take up the DNA, which was monitored by transient GUS gene expression. EHA105 at 0.3 O.D and LBA4404 at 0.5 O.D were found to be compatible in giving optimal levels of transient GUS expression.