Schematic of Plant Parasitic Nematode Effector Production and Infection.
Parasitic cyst nematodes contain two primary classes of gland cells (dorsal [DG] and subventral [SvG]). Dorsal gland-expressed effectors often contain a dorsal gland box (DOG box) in their promoter regions. We hypothesize that an as yet unidentified dorsal gland master regulator (DOGMR), specifically expressed in the dorsal gland cell, will recognize this motif, initiating the processes of transcription, translation, and secretion through the endoplasmic reticulum (ER) Golgi complex to secretory granules (SG). SGs release effectors (filled triangles) into the lumen of the stylet, to be delivered both in the apoplasm and across the plant plasma membrane (PM). The DOG box reveals the extended repertoire of effectors that rapidly manipulate plant development and immunity, ultimately resulting in a novel syncytial organ with reduced and fragmented vacuole (V), multiple enlarged nuclei (N), and proliferated ER, Golgi, and plastids (P).