Pyramided transgenic jute (Corchorus capsularis) with biotic stress resistance and herbicide tolerance

Abstract

Jute (Corchorus sp.) is a commercially important bast (stem) fibre–producing crop. The natural, long, lustrous, and strong jute fibres are globally popular for their domestic and industrial utility. Unfortunately, jute fibre production is under continuous threat from three major agricultural challenges: insect infestation (predominantly lepidopteran insects), fungal infection, and weed management issues. Creating jute plants that could themselves overcome these three challenges would be spectacular. Hence, multi–trait transgenic lines were developed by incorporating three genes—cry1Ab/Ac (encodes Bt δ–endotoxin for Lepidopteran insect resistance), chi11 (encodes chitinase for fungus resistance), and bar (encodes phosphinothricin acetyltransferase (PAT) for glufosinate herbicide tolerance)—into the white jute (C. capsularis) cultivar JRC–321 through Agrobacterium–mediated co–transformation. A bioassay–based event selection strategy was applied for the selection of the transformed jute lines. Each plant was tested through consecutive bioassays involving herbicide, insects, and fungus, followed by molecular and biochemical validation. The functions of the three genes, incorporated in the greenhouse–grown transgenic progeny plants, were confirmed for every generation (till the T2 generation). The plants were able to detoxify the glufosinate herbicide Basta®, resist the two devastating lepidopteran pests tested: hairy caterpillars (Spilarctia obliqua) and semiloopers (Anomis sabulifera), and recover from the stem rot–causing fungal pathogen Macrophomina phaseolina, without compromising agronomic characteristics or fibre quality. The white jute lines thus developed may be effectively used to increase the production of quality jute fibres, meet local and global demands, and minimise input cultivation costs.