Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 13, 2007
Publication Date: January 17, 2007
Citation: Wubben, M., Callahan, F.E. 2007. Identification of transcripts induced during the cotton - root-knot nematode incompatible interaction by suppressive subtractive hybridization [abstract]. Proceedings Plant and Animal Genome Conference. Available: http:\\www.intl-pag.org\is\abstracts\PAG15-P05r-656. Technical Abstract: Meloidogyne incognita, the root-knot nematode (RKN), is a destructive sedentary endoparasite of Upland cotton (Gossypium hirsutum). G. hirsutum lines resistant to RKN have been developed and considerable effort expended toward the genetic mapping of RKN resistance loci within these lines. However, there is no information regarding the molecular events which mediate RKN resistance in cotton. Therefore, we constructed a SSH cDNA library enriched for transcripts differentially expressed between the resistant line M315 and the susceptible line M8 during RKN infection. Because the primary resistance response in M315 occurs during early gall development, amplified cDNA from M315 and M8 immature galls was used as ‘tester’ and ‘driver,’ respectively, for SSH cDNA library construction. 1,056 clones were bi-directionally sequenced and clustered to yield 609 non-overlapping unique expressed sequence tags (ESTs) (93% minimum identity and 40-bp overlap). BLASTX analysis revealed that many of the ESTs shared identity with proteins involved in classical resistance gene-mediated defense signaling including NADPH oxidase, peroxidase, SGT1 and NDR1. ESTs predicted to encode leucine-rich repeat receptor kinases and other stress-related proteins were identified that do not share significant identity (P > 1e-10) with sequences in the cotton EST database. Real-time RT-PCR analysis confirmed the up-regulation of selected transcripts in RKN-infected M315 relative to RKN-infected M8, indicating that the ESTs generated from this library likely represent genes that are differentially induced between M315 and M8 during the early stages of infection by RKN.