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

Mikhail A. Filyushin,Anna V. Shchennikova,Olga K. Anisimova,Elena Z. Kochieva

doi:10.3390/plants10040720

Abstract

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

Highlights

IntroductionPublisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations
We identified and characterized seven genes encoding class I chitinases in A. sativum cv
The chitinase gene promoters contained hormone- and stress-responsive elements, including those associated with responses to fungal pathogens and their elicitors, suggesting that the putative garlic chitinases participate in local acquired resistance, whereas AsCHI2, AsCHI homologues were 310 (AsCHI3), and AsCHI7 may be involved in systemic acquired resistance

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Plants belonging to the Allium genus are widely cultivated for their culinary and medicinal properties [1]. Throughout their life cycle, onions (including garlic), like all other agricultural plants, are infected with fungi, in particular Fusarium spp., which are the most viable and destructive soil-dwelling crop pathogens causing Fusarium basal rot Cepae) and bulb rot (F. proliferatum) [2,3,4,5]. Cepae is responsible for 60% of the world’s garlic crop losses Throughout their life cycle, onions (including garlic), like all other agricultural plants, are infected with fungi, in particular Fusarium spp., which are the most viable and destructive soil-dwelling crop pathogens causing Fusarium basal rot (F. oxysporum f. sp. cepae) and bulb rot (F. proliferatum) [2,3,4,5].

Methods

Discussion

Conclusion