CRISPR/Cas9-targeted mutagenesis of a representative member of a novel PR10/Bet v1-like protein subfamily significantly reduces rice plant height and defense against Meloidogyne graminicola
Zhiwen Li, Qiuling Huang, Borong Lin, Bin Guo, Jing Wang, Chunhui Huang, Jinling Liao, Kan Zhuo
Abstract
Abstract Plant PR10/Bet v1-like proteins are involved in defense against microbial pathogens, however, whether they participate in host defense against plant-parasitic animals including nematodes remains unknown. Here, according to the phylogeny, sequence-similarity, and secondary structure analyses, we found that the rice OsBet v1 protein and its homologs constitute a new subfamily of PR10/Bet v1-like protein. Reverse transcription-quantitative PCR assay showed that OsBet v1 was highly expressed in rice roots and induced by Meloidogyne graminicola infection. Using a transient expression assay in rice protoplasts, we demonstrated that OsBet v1 was localized in the cytoplasm and nucleus. Furthermore, CRISPR/Cas9-targeted mutagenesis of OsBet v1 significantly increased rice susceptibility to M. graminicola , but reduced rice plant height. In addition, the expression levels of two peroxidase genes ( peroxidase 5 and peroxidase 56 ) were significantly down-regulated in OsBet v1 knockout mutants compared with those in wild-type rice plants. Taken together, this study identified a new PR10/Bet v1-like protein subfamily in plant and revealed the involvement of OsBet v1, a representative member of the subfamily, in rice growth and defense against M. graminicola . This provides a new insight into the role of plant PR10/Bet v1-like proteins in plant–nematode interactions.