Mating System in the Brown Rot Pathogens Monilinia fructicola, M. laxa, and M. fructigena

Abstract

Monilinia fructicola, M. laxa, and M. fructigena are the most important pathogens responsible for brown rot disease of stone and pome fruits. Information on their mating system and sexual behavior is scant. A mating-type-specific PCR-based assay was developed and applied to 155 Monilinia isolates from 10 countries and 10 different host plants. We showed that single isolates carry only one of two opposite idiomorphs at the MAT1 locus consistent with a heterothallic mating system for all three species. MAT1-1 and MAT1-2 mating types were detected in similar proportions in samples of isolates of each species and hence there do not appear to be genetic obstacles to the occurrence of sexual reproduction in their populations. Inter simple sequence repeat markers suggested that asexual reproduction is prevalent, but that sexual recombination occurs in M. fructicola populations in Italy. The genetic architectures of the MAT1 loci of the three pathogens were analyzed. MAT1-1 and MAT1-2 idiomorphs are flanked upstream and downstream by the APN2 and SLA2 genes and resemble those of Botrytis cinerea and other heterothallic fungi in the family Sclerotiniaceae. Each idiomorph contains a specific couple of genes, MAT1-1-1 (with alpha-box domain) and MAT1-1-5 in MAT1-1, and MAT1-2-1 (with HMG-box domain) and MAT1-2-10 in MAT1-2. Small gene fragments (dMAT1-1-1 and dMAT1-2-1) from the opposite idiomorph were detected close to their flanking regions. Constitutive expression of the four MAT1 genes during vegetative growth was ascertained by transcriptomic analysis (RNA-Seq). Antisense transcription of the MAT1-1-1 and MAT1-2-1 genes and intergenic transcribed regions of the MAT1 locus were detected. These results represent new insights into the mating systems of these three economically-important pathogens which could contribute to improve the knowledge on their population biology.

New High-Quality Draft Genome of the Brown Rot Fungal Pathogen Monilinia fructicola

“…The strain was grown in potato dextrose broth (infusion from 200 g peeled and sliced potatoes kept for 1 h at 60 °C, with 20 g dextrose, adjusted to pH 6.5, per liter) for 48 h at 25 ± 1 °C, in darkness and under shaking (150 rpm). The strain was characterized at both the phenotypic and molecular levels (Abate, De Miccolis Angelini, et al. 2018; Abate, Pastore, et al 2018; De Miccolis Angelini et al.…”

Phylogenetic relationships and genetic diversity of Monilinia spp. isolated in Poland based on housekeeping‐ and pathogenicity‐related gene sequence analysis

“…fructigena , and M . laxa , confirmed a lack of genetic obstacles to the occurrence of sexual reproduction in their populations (Abate et al, 2018). However, the ability to form mating organs does not guarantee that sexual bodies are always formed in Monilinia fungi.…”

“…sclerotiorum , little is known about the mating system and sexual behaviour of Monilinia spp. (Abate et al, 2018). More than 10 years of studies on the genetic diversity of these fungi suggest that recombination is an important source of variation only in M .…”

Genome sequence of the brown rot fungal pathogen Monilinia fructigena

“…A monoconidial strain of M. fructigena , Mfrg269, was derived from plum during monitoring of Monilinia populations present on stone fruit in southern Italy (Tursi, Basilicata) [ 8 ]. The strain was characterised both at the phenotypic and molecular levels [ 7 – 9 ]. The strain was grown in liquid medium (2% malt extract; Oxoid) for 36 h at 24 ± 1 °C, in darkness and under shaking (150 rpm).…”