Identification of six transcripts encoding putative receptor-like protein kinase (RLK) and their expression profiles in Vitis flexuosa infected with pathogens

Abstract

Grapevines are exposed to various diseases, resulting in serious problems. However, cultivation of grapevines carrying genes related to disease resistance is a potential strategy for management of diseases during grape production. Receptor-like protein kinase (RLK) is an important gene related to disease resistance in plants. We identified six transcripts of receptor-like protein kinase genes showing different expression patterns, VfRLK586 (Vitis flexuosa Receptor-Like Kinase 586), VfRLK2422, VfRLK5099, VfRLK29473, VfRLK29610, and VfRLK55257 from transcriptome analysis based on the Next Generation Sequencing (NGS) of V. flexuosa inoculated with Elsinoe ampelina. The lengths of these genes were 1531, 2800, 2968, 2446, 3548 and 3468bp, and their encoded proteins composed of 401, 625, 918, 642, 1039 and 1012 amino acids, respectively. The predicted amino acid sequences showed typical protein kinase domain in all six transcripts. Among these, VfRLK2422, VfRLK5099, VfRLK29473, VfRLK29610 and VfRLK55257 were typical receptor-like kinase genes containing both intracellular and extracellular parts, while VfRLK586 was receptor-like cytoplasmic kinase (RLCK) gene. Of the six transcripts, only VfRLK2422 showed upregulated expression against all tested pathogens at all time points. VfRLK5099 showed upregulation against Rhizobium vitis and Colletotrichum gloesporioides and downregulated expression against E. ampelina and Botrytis cinerea at later time points. VfRLK29473 showed downregulated expression in later time points against all pathogens. The expression of VfRLK29610 was upregulated against R. vitis and C. gloeosporioides, but downregulated against B. cinerea. All tested genes showed responses with high and differential expression against pathogens, indicating that all RLK genes may be involved in plant resistance responses against different pathogens in grapevines.