| Summary: | Vegetables of the <i>Allium</i> genus are prone to infection by <i>Fusarium</i> 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 (<i>Allium sativum</i> L.) chitinases is limited. In the present study, we identified seven class I chitinase genes, <i>AsCHI1–7</i>, in the <i>A. sativum</i> cv. Ershuizao genome, which may have a conserved function in the garlic defense against <i>Fusarium</i> attack. The <i>AsCHI1–7</i> promoters contained jasmonic acid-, salicylic acid-, gibberellins-, abscisic acid-, auxin-, ethylene-, and stress-responsive elements associated with defense against pathogens. The expression of <i>AsCHI2</i>, <i>AsCHI3</i>, and <i>AsCHI7</i> genes was constitutive in <i>Fusarium</i>-resistant and -susceptible garlic cultivars and was mostly induced at the early stage of <i>F. proliferatum</i> infection. In roots, <i>AsCHI2</i> and <i>AsCHI3</i> mRNA levels were increased in the susceptible and decreased in the resistant cultivar, whereas in cloves, <i>AsCHI7</i> and <i>AsCHI5</i> expression was decreased in the susceptible but increased in the resistant plants, suggesting that these genes are involved in the garlic response to <i>Fusarium proliferatum</i> attack. Our results provide insights into the role of chitinases in garlic and may be useful for breeding programs to increase the resistance of <i>Allium</i> crops to <i>Fusarium</i> infections.
|
|---|