Genome-Wide Identification and Expression of Chitinase Class I Genes in Garlic ( L.) Cultivars Resistant and Susceptible to .

Vegetables of the genus are prone to infection by fungi. Chitinases of the GH19 family are pathogenesis-related proteins inhibiting fungal growth through the hydrolysis of cell wall chitin; however, the information on garlic ( L.) chitinases is limited. In the present study, we identified seven class I chitinase genes, , in the cv. Ershuizao genome, which may have a conserved function in the garlic defense against attack. The promoters contained jasmonic acid-, salicylic acid-, gibberellins-, abscisic acid-, auxin-, ethylene-, and stress-responsive elements associated with defense against pathogens. The expression of , , and genes was constitutive in -resistant and -susceptible garlic cultivars and was mostly induced at the early stage of infection. In roots, and mRNA levels were increased in the susceptible and decreased in the resistant cultivar, whereas in cloves, and expression was decreased in the susceptible but increased in the resistant plants, suggesting that these genes are involved in the garlic response to attack. Our results provide insights into the role of chitinases in garlic and may be useful for breeding programs to increase the resistance of crops to infections.