A LysM Domain-Containing Protein LtLysM1 Is Important for Vegetative Growth and Pathogenesis in Woody Plant Pathogen Lasiodiplodia theobromae

• Published in: The plant pathology journal Vol. 36; no. 4; pp. 323 - 334
• Main Authors: Harishchandra, Dulanjalee Lakmali, Zhang, Wei, Li, Xinghong, Chethana, Kandawatte Wedaralalage Thilini, Hyde, Kevin David, Brooks, Siraprapa, Yan, Jiye, Peng, Junbo
• Format: Journal Article
• Language: English
• Published: 한국식물병리학회 01-08-2020; Korean Society of Plant Pathology; Hanrimwon Publishing Company
• Subjects: grapevine; n-glycosylation; pathogenicity; secreted protein; 농학; pathogenicity; grapevine; N-glycosylation; secreted protein
• ISSN: 1598-2254; 2093-9280
• DOI: 10.5423/PPJ.OA.05.2020.0084

Lysin motif (LysM) proteins are reported to be necessary for the virulence and immune response suppression in many herbaceous plant pathogens, while far less is documented in woody plant pathogens. In this study, we preliminarily characterized the molecular function of a LysM protein LtLysM1 in woody plant pathogen
Lasiodiplodia theobromae.
Transcriptional profiles revealed that LtLysM1 is highly expressed at infectious stages, especially at 36 and 48 hours post inoculation. Amino acid sequence analyses revealed that LtLysM1 was a putative glycoprotein with 10 predicted
N
-glycosylation sites and one LysM domain. Pathogenicity tests showed that overexpressed transformants of
LtLysM1
displayed increased virulence on grapevine shoots in comparison with that of wild type CSS-01s, and RNAi transformants of
LtLysM1
exhibited significantly decreased lesion length when compared with that of wild type CSS-01s. Moreover, LtLysM1 was confirmed to be a secreted protein by a yeast signal peptide trap assay. Transient expression in
Nicotiana benthamiana
together with protein immunoblotting confirmed that LtLysM1 was an
N
-glycosylated protein. In contrast to previously reported LysM protein Slp1 and OsCEBiP, LtLysM1 molecule did not interact with itself based on yeast two hybrid and co-immunoprecipitation assays. These results indicate that LtLysM1 is a secreted protein and functions as a critical virulence factor during the disease symptom development in woody plants.