The effector MgCRT1 of Meloidogyne graminicola targets the pathogenesis-related (PR) protein OsPR1#101 to facilitate nematodes parasitism in rice.

BACKGROUND

The root-knot nematodes Meloidogyne graminicola (M. graminicola) are an important pathogenic nematode that harms rice. During infection, plant parasitic nematodes use needles to penetrate the plant cell wall, and secrete effectors into cells, thus destroying the root system's ability to absorb water and nutrients. Rice root-knot nematode disease is difficult to control once established, with traditional chemical methods prone to pollution and slow efficacy. Exploring the pathogenic mechanism of effector proteins of plant parasitic nematodes will provide a solid theoretical basis for the utilization of plant innate immunity and genetic engineering or molecular breeding of nematode resistance.

RESULTS

In this study, we characterized a pathogenesis-related protein OsPR1#101, which was targeted by the effector MgCRT1. We found that OsPR1#101 interacted directly with MgCRT1 in vitro and in vivo. The expression of OsPR1#101 was significantly induced in rice at the early stage of M. graminicola infection, but it was decreased in the late stage. Meanwhile, the expression of OsPR1#101 was significantly suppressed in the MgCRT1-overexpression line. Knocking out OsPR1#101 resulted in enhanced susceptibility to M. graminicola. However, overexpression of OsPR1#101 did not affect rice resistance against M. graminicola.

CONCLUSION

In conclusion, when M. graminicola nematodes secrete MgCRT1 into rice, MgCRT1 interacts with OsPR1#101 to interfere with rice defense to promote nematode parasitism. This finding is significant as it deepens our understanding of the molecular mechanism of nematode-plant interaction, which can potentially lead to the development of new strategies for nematode control in rice. © 2025 Society of Chemical Industry.