Elucidation of the molecular responses during the primary infection of wild blueberry phenotypes with Monilinia vaccinii-corymbosi under field conditions

Abstract

Background Monilinia blight caused by Monilinia vaccinii-corymbosi (Reade) Honey (M.vc) is a major disease of wild blueberry that can result in severe crop losses in the absence of an integrated disease management programme. The fungus causes blight in the emerging floral and vegetative buds, but the degree of susceptibility varies among the different wild blueberry phenotypes, ranging from the highly susceptible V. a. f. nigrum to the moderately susceptible V. angustifolium and the least susceptible V. myrtilloides. Results The present study evaluated the defense responses of these major phenotypes during their primary infection (floral buds) with M.vc. The temporal expression profiles of PR genes (PR3 and PR4) and the flavonoid pathway structural genes (CHS, ANS, ANR, DFR and FLS) were analysed. The PR3 and PR4 gene expression profiles revealed that V. myrtilloides responded to M.vc infection by activating the expression of both PR genes. V. a. f. nigrum, on the other hand, failed to activate these genes, while V. angustifolium, exhibited an intermediate response. Our study with the flavonoid pathway genes indicated variability in activation of the genes during post-infection time points with ANS and ANR in V. myrtilloides, FLS in V. angustifolium and no response observed in V. a. f. nigrum. Conclusions Altogether, this study highlights that the degree of phenotype susceptibility is associated with the timely activation of host defense responsive genes. Data obtained in this study provided a starting point for a better understanding of the wild blueberry- M. vaccinii-corymbosi pathosystem.

Modulation of defense genes and phenolic compounds in wild blueberry in response to Botrytis cinerea under field conditions

“…Given the functions of chitinases, it is not surprising that many studies have reported that chitinase encoding genes ( PR3 and PR4 ) are up-regulated during host–pathogen interaction [ 13 , 36 , 37 ]. The early expression of PR3 and PR4 genes in the Va phenotypes, as well as the short and medium stem Vm phenotypes in this study agrees with previous studies [ 19 , 38 ]. For instance, Koskimäki et al [ 19 ] reported the accumulation of PR4 genes in V. myrtillus 12 h after inoculation with B. cinerea .…”

Vaccinium uliginosum L. (bog bilberry) and the search for its alleged toxicity: a review

“…There have been no studies yet regarding the toxic compounds in Monilinia genus growing on Ericaceae berries. The only scientific attention they have gotten so far are studies analysing the morphology and life cycle of the fungus, impact of Monilinia blight on berry plantations, strategies to prevent them and analyses of the stress-responsive genes in Vaccinium plants (Woronin, 1888;Kotlaba and Pilát, 1952;Munda, 2011;Jose et al, 2021). Not even M. Vaccinii-Corymbosi has been investigated for potential toxicity, despite being the most severe disease of commercially grown blueberries, accounting for up to 70% crop loss in some plantations if left unmanaged (Cucak et al, 2022).…”