Giant cell wall molecular structure and role of plant cell wall related genes on development of Meloidogyne incognita
R. BOZBUGA (1), C. Lilley (1), J. Knox (1), PE Urwin (1) Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, West Yorkshire, United Kingdom

The root knot nematodes Meloidogyne incognita induce morphologically distinct cells in host roots, termed giant cells from which they feed for the entirety of their parasitic life. In situ immunochemical analysis has been carried out to reveal the presence and distribution of a range of glycan, pectin and glycoproteins in the walls of giant cells and surrounding root cells of infected Arabidopsis thaliana, Vigna angularis (aduki bean) and Zea mays (maize) infected by M. incognita. Results revealed that high-esterified pectic homogalacturonan, xyloglucan and pectic arabinan were common glycans within the giant cell walls of Arabidopsis, aduki bean and maize. Xylan, feruloylated xylan and mix linkage glucan were found in giant cell walls of the maize host. The giant cell walls of Arabidopsis and maize but not aduki bean contained mannan and galactan. Arabinogalactan protein was abundant in giant cell walls in maize but not in Arabidopsis and aduki bean. Arabidopsis cell wall- related mutants were investigated to define the role of specific host genes in giant cell development. Knockout mutants of glycoprotein-related genes supported more and larger female nematodes with induced giant cells with thicker walls. Conversely, hemicellulose-related gene knockdowns resulted in decreased nematode size and number, fewer, smaller galls, and increased giant cell wall thickness. Pectin-related gene knockdowns revealed more disparate results indicative of the specific gene. The role of cell wall degrading enzymes secreted by the nematode in the development of the nematode-plant interaction is being investigated by using RNAi knock-down.

Abstract Number: P7-157
Session Type: Poster