a1 Department of Pure and Applied Biology, The University, Leeds LS2 9JT
The invasion and establishment of Heterodera glycines has been studied for 0–120 h after addition to host roots using a synchronized infection system. A high degree of synchrony in development was noted, with juvenile nematodes reaching their feeding sites adjacent to the root endodermis and discharging their subventral pharyngeal glands by 24 h post-invasion (p.i.). The moult to the 3rd-stage juvenile occurred approximately 89 h after entry to the root. Using an enzyme-linked immunosorbent assay with monoclonal antibodies (MAbs) whose tissue specificities had already been defined by immuno-cytochemistry, it was found that MAbs recognizing intestinal lipid droplets and granules showed a major increase in reactivity 18–24 h p.i. before declining by 39 h p.i. In contrast, the reactivity of two MAbs recognizing adult cuticle increased significantly only after 89 h p.i., following the second moult. MAbs to the two subventral pharyngeal gland cells showed a variety of patterns of changing reactivity during the experiment. One increased within 24 h of invasion before declining whereas a second fell without any initial rise. Two further MAbs specific for the subventral glands initially declined but showed a secondary increase in reactivity after 72 h and could be detected in adult females. This pattern was also seen in a MAb specific for the dorsal pharyngeal gland cell. These changes are discussed in the context of events taking place following invasion, with particular reference to the initiation and maintenance of a feeding syncytium by the developing nematode.
(Accepted November 19 1988)
p1 Department of Biochemistry, The University of Bath.