Discovery of genes that function when parasitic plants infect host plants

August 7, 2020

A mechanism common with plant grafting

A joint group of researchers from Nagoya University and RIKEN CSRS has identified the genes needed when a parasitic plant infects a host plant.
 Since parasitic plants infect roots and stems of quite a wide range of host plants and have a high rate of reproduction, the damage caused by such plants on agricultural crops is a global concern. In a previous study, the research group suggested that plant grafting among different species (interfamily grafting), which had been considered impossible, can be done with Nicotiana plants. The group also identified the genes involved in such grafting. In this present study, they found that the model parasitic plant Phtheirospermum japonicum can be grafted onto interfamily species, just like Nicotiana plants. When transcription products of P. japonicum were compared at the time of infection and at the time of grafting, it was found that the expression of β-1,4-glucanase increased in both cases. This increase in β-1,4-glucanase expression was similarly observed when Nicotiana plants were grafted onto interfamily species, and β-1,4-glucanase is thought to be involved in cell wall reconstruction near the graft interface. The present study also suggested that the time of gaining β-1,4-glucanase expression coincided with the gaining of parasitic ability in the evolutional tree of parasitic plants. The study also revealed that parasitism is suppressed when the expression of β-1,4-glucanase is temporarily reduced in P. japonicum.

It is anticipated that agricultural damage can be reduced in the future by suppressing infection of parasitic plant to crops, through artificial inhibition of β-1,4-glucanase activity

Original article
Communications Biology doi:10.1038/s42003-020-01143-5
K.Kurotani, T. Wakatake, Y. Ichihashi, K. Okayasu, Y. Sawai, S. Ogawa, S. Cui, T. Suzuki, K. Shirasu, M. Notaguchi,
"Host-parasite tissue adhesion by a secreted type of β-1,4-glucanase in the parasitic plant Phtheirospermum japonicum".
Ken Shirasu
Group Director
Plant Immunity Research Group