Abstract
Botrytis cinerea is a pathogenic fungus that causes gray mold disease in a broad range of crops. The high intraspecific variability of B. cinerea makes control of this fungus very difficult. Here, we isolated a variant B05.10M strain from wild-type B05.10. The B05.10M strain showed serious defects in mycelial growth, spore and sclerotia production, and virulence. Using whole-genome resequencing and site-directed mutagenesis, a single nucleotide mutation in the adenylate cyclase (BAC) gene that results in an amino acid residue (from serine to proline, S1407P) was shown to be the cause of various defects in the B05.10M strain. When we further investigated the effect of S1407 on BAC function, the S1407P mutation in bac showed decreased accumulation of intracellular cyclic AMP (cAMP), and the growth defect could be partially restored by exogenous cAMP, indicating that the S1407P mutation reduced the enzyme activity of BAC. Moreover, the S1407P mutation exhibited decreased spore germination rate and infection cushion formation, and increased sensitivity to cell wall stress, which closely related to fungal development and virulence. Taken together, our study indicates that the S1407 site of bac plays an important role in vegetative growth, sclerotial formation, conidiation and virulence in B. cinerea.
Highlights
Botrytis cinerea is a typical necrotrophic pathogen with a broad host range, affecting more than 1000 plant species [1]
In B. cinerea, key components of the cyclic AMP (cAMP) pathway include bac, bcpkaR and bcpka1, knockout mutants of which are defective in growth and pathogenicity [9]
Phenotypes of B05.10 and B05.10M are Significantly Different in Vegetative Growth, Sclerotial Formation, Conidiation, and Virulence
Summary
Botrytis cinerea is a typical necrotrophic pathogen with a broad host range, affecting more than 1000 plant species [1]. B. cinerea can be propagated asexually through conidia and sclerotia and sexually through ascospores during its life cycle [3,4] It possesses a versatile arsenal of pathogenic factors, including cell wall-degrading enzymes, phytotoxins (botrydial and botcinic acid), phytohormones, reactive oxygen species, oxalic acid, and small RNAs, that are used to complete the infection process and result in the decay of plant tissues [1,3,5]. In B. cinerea, key components of the cAMP pathway include bac (the gene encoding adenylate cyclase in B. cinerea), bcpkaR and bcpka, knockout mutants of which are defective in growth and pathogenicity [9]. Using whole-genome resequencing and site-directed mutagenesis, we confirmed a single mutation, S1407P, in the bac that results in development and pathogenic defects in B05.10M strain. The novel findings regarding the identification of a deterministic functional site (S1407) in BAC provide new insight regarding the function of BAC in fungal pathogenesis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
