Life traits of four Botryosphaeriaceae species and molecular responses of different grapevine cultivars or hybrids

Abstract

Botryosphaeriaceae is a fungal family comprising many species involved in botryosphaeria dieback, a worldwide grapevine trunk disease. Currently, the interactions between Botryosphaeriaceae species and various grapevine cultivars are poorly understood and little data is available. This study investigated various life traits of five isolates belonging to four species of Botryosphaeriaceae found in French vineyards (Diplodia mutila, Diplodia seriata, Lasiodiplodia viticola and Neofusicoccum parvum). The two species N. parvum and L. viticola exhibited the highest optimal growth temperature and the best growth rates. They were also responsible for the most extensive necrosis and cankers in three Vitis vinifera cultivars (Cabernet Sauvignon, Merlot and Ugni-Blanc) that differed in susceptibility to botryosphaeria dieback, and in two genotypes resistant to downy and powdery mildew (RV4 and RV5). Identification of the extracellular toxins produced by isolates in culture media showed that the N. parvum isolate had a different metabolite profile from the others, producing terremutin and salicylic acid derivatives, which are known to be compounds associated with virulence. In a second step, life traits were associated with nondestructive monitoring of gene expression involved in the defence mechanisms of five grapevine cultivars and genotypes after inoculation of wood cuttings with Botryosphaeriaceae. The transcript analyses were carried out at different times and were associated with principal component analysis (PCA). Each cultivar presented a specific transcript signature and several transcripts were correlated either with the size of necrosis/cankers or with symptom reduction, thus offering useful markers for breeding or estimating the defence status of plants.

Dual RNA Sequencing of Vitis vinifera during Lasiodiplodia theobromae Infection Unveils Host–Pathogen Interactions

“…Lastly, Giacomelli et al [54] also reported the expression of PR-12 transcripts in grape tissues infected with B. cinerea , suggesting a role in the defense. As reported for other Botryosphaeriaceae species, such as N. parvum , L. viticola , Diplodia mutila , and D. seriata [55], the expression of genes coding for PR proteins in grapevine is significantly intense within a short term after the first contact with pathogens.…”

Grapevine Botryosphaeria dieback fungi have specific aggressiveness factor repertory involved in wood decay and stilbene metabolization

“…This result could be related to a higher growth of N . parvum after artificial wood inoculation already shown by various authors [ 19 , 20 , 69 , 9 , 70 , 71 , 23 , 72 ]. Our results are also consistent with the trunk disease fungi genome analysis of Morales et al [ 34 ], showing that ascomycete trunk pathogens have a wider array of enzymes that target cellulose and hemicellulose compared to other grapevine pathogens.…”

“…seriata , whereas N . parvum is characterized by the synthesis of dihydrotoluquinones, epoxylactones, dihydroisocoumarins and hydroxybenzoic acids [ 23 , 27 ].…”

Susceptibility of different grapevine (Vitis vinifera L.) cultivars to Diplodia seriata and Diplodia mutila

“…Morphological analysis (Pozoulet et al, 2014) showed that vessels from the Merlot cultivar were smaller than those of the Thompson Seedless cultivar. In addition, studies conducted using two-month-old plants of Cabernet Sauvignon, Merlot and Ugni Blanc with 10-12 true leaves showed significant differences in the mean length of the internal necrosis and external canker between the cultivars above mentioned, inoculated with D. mutila and D. seriata (Bellée et al, 2017). Thus, it appears that a correlation exists between vessel size and susceptibility to Esca or other fungi causing grapevine trunk diseases, which could explain the differences observed in the susceptibility to D. mutila, among the canes from different grapevine cultivars tested, as well as the difference observed for the Malbec cultivar in response to inoculation with D. seriata (Figure 2).…”