Submitted to: Experimental Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/17/2013
Publication Date: 4/15/2013
Citation: Tucker, M.L., Yang, R. 2013. An IDA-like gene is expressed in root-knot nematodes (Meloidogyne spp.). Experimental Parasitology. 134:165-170. Interpretive Summary: Nematodes are the most economically damaging pathogens of soybean. Pathogenic nematodes induce the formation of a feeding structure in the plant root by co-opting developmental programs innate to the plant root. A protein named IDA has been demonstrated to be an important inductive signal for development in model plants. We discovered and have characterized an IDA-like gene in root-knot nematodes that can putatively alter cellular development in nematode infected roots. A better understanding of how nematodes induce the formation of a functional feeding structure in roots will greatly improve the ability of scientists and industrial partners to control nematode infection of soybean and other agriculturally important plants.
Technical Abstract: Inflorescence deficient in abscission (ida) is an Arabidopsis mutant that does not abscise (shed) it’s flower petals. The IDA gene encodes a small, secreted protein that putatively binds to two redundant receptor like kinases (HAESA and HAESA-like2) that initiates a signal transduction pathway which alters the expression of a small group of KNOX-like transcription factors. We identified and IDA-like gene in the genomic sequence for Meloidogyne incognita and M. hapla, and two ESTs in M. chitwoodi. No orthologous sequences were found in any other genus of nematode. Transcript for both M. incognita and M. hapla were found in total RNA isolated from separately infected root systems of tomato, Solanum lycopersicum. Five prime and three prime RACE of RNA from M. incognita infected tomato roots revealed an RNA sequence of 392 nt including a poly A tail of 38 nt. Its open reading frame encodes a 47 aa protein that includes a predicted 28 aa N-terminal signal peptide. Expression of MiIDA is very low in eggs and J2 and rapidly increases in the first few days post inoculation and then declines as the nematode develops inside the gull. A role for root-knot IDA is discussed.