Submitted to: Society of Nematologists Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 10, 1998
Publication Date: N/A
Technical Abstract: Two gene constructs were inserted separately into cotton cv. Coker 312 via Agrobacterium tumefaciens. The first (construct A) combined the NRE (nematode response element) promoter, a truncated naturally occurring pro- moter from the root-specific tobacco gene TobRB7, with an attenuated barnase (cell toxin) coding region. The second (construct B) combined the NRE promoter with antisense of a cotton homologue of an abundant tobacco aquaporin regulating cell volume. The strategy for achieving nematode resistance with both constructs was dysfunction or autolysis of the giant nurse cells in nematode feeding sites in roots. Plantlets were confirmed transgenic by PCR and tested for nematode resistance in growth chambers (26-30 deg C) by transplanting plantlets into 500-cm3 pots containing a 6:1 (v:v) mixture of sand and vermiculite, inoculating with 1,000 Meloidogyne incognita juveniles per pot, and extracting nematode eggs from roots 60 days later. GUS reporter gene expression in infected roots indicated NRE expression may be specific to infection sites in cotton roots. Several promising cell lines with construct A or B were identified and true seed- lings are being tested against M. incognita and Rotylenchulus reniformis.