Recently, an article entitled “Two venom allergen-like proteins, HaVAP1 and HaVAP2, are involved in the parasitism of Heterodera avenae” was published on Molecular Plant Pathology by Plant Nematode Disease Research Group led by Prof. PENG Deliang’s from the Institute of Plant Protection, Chinese Academy of Agricultural Sciences.

The stylet and the effectors of nematode are indispensable components during the parasitism of plant parasitic nematode. The parasitism transitions of sedentary endoparasitic nematodes are composed of attraction, infection, movement, seeking and establishing feeding sites for development in hosts. The functions of effectors include the expansion or degradation of cell walls, suppressing plant immunity, intervening the metabolism of hosts. Due to the disability of infection in a model host, the studies of parasitism mechanism of cereal cyst nematode (CCN) remain at the starting stage.

Cereal cyst nematode Heterodera avenae is an economically important pathogen during wheat yield in China. In this study, we cloned two venom allergen-like proteins coding genes from cereal cyst nematodes, named VAP1 and VAP2, respectively. We found that their expression profiles were different from each other. Up-regulation of VAP1 transcript occurred at early stages, and the transcript signal accumulated in subventral glands. While VAP2 transcript increased at later stages and accumulated in dorsal gland. When co-expressed with RFP in tobacco, the signals of VAP1 were in chloroplasts whereas VAP2 was expressed in nucleus. Both proteins suppressed BAX-induced cell death in tobacco leaves. RNAi of VAP1 showed significant increases of juveniles in roots. The down-regulation of VAP2 mRNA hampered the parasitism and generation of nematodes. In addition, VAP2 interacted with a CYPRO4-like protein (CLP) from barley. These studies revealed two VAPs which play different roles during the parasitism of CCN, broadening our understanding of the parasitism mechanism of phytonematode.

This work was supported by the Natural Science Foundation of China and the Special Fund for Agro-Scientific Research in the Public Interest.

More details are available on the link below: https://onlinelibrary.wiley.com/doi/10.1111/mpp.12768

By Kong Lingan(lakong@ippcaas.cn)