Endophytic Fungi as Potential Biological Control Agents against Grapevine Trunk Diseases in Alentejo Region

Abstract

Grapevine trunk diseases (GTDs) are the most widespread fungal diseases, affecting grapevines in all the major growing regions of the world, and their complete eradication is still not possible. Aiming to search alternatives to avoid the spread and high incidence of these diseases, the present work intended to molecularly identify the grapevine endophytic community, the phytopathogenic fungi associated with GTDs in vineyards within the Alentejo region, and to test potential antagonist microorganisms as biological control candidates against GTDs-associated fungi. Grapevine endophytic community showed a wide variety of fungi in GTDs’ asymptomatic and symptomatic plants, nine of them previously described as GTDs-associated fungi. GTDs prevalent fungi identified in symptomatic plants were Diaporthe sp., Neofusicoccum sp., and H. viticola. Almost all these fungi were also detected in asymptomatic plants, which shows the importance of investigating the interactions of fungal communities and confirms the need for early diagnosis of these diseases. Direct inhibition antagonism tests were performed among identified endophytes and GTDs phytopathogenic fungi, and all the endophyte fungi showed potential as biocontrol agents. Our findings suggest that endophytes are promising candidates for their use in biological control due to their antagonistic activity against the mycelia growth of some GTDs-associated fungi.

The Endophytic Strain Trichoderma asperellum 6S-2: An Efficient Biocontrol Agent against Apple Replant Disease in China and a Potential Plant-Growth-Promoting Fungus

“…For example, endophytic fungi, isolated from Pelargonium graveolens, Melia azedarach, Chenopodium album, and Malva parviflora, are rich sources of secondary metabolites for use in bio-control [13]. Almeida et al found that endophytes were promising biological control agents because of their antagonistic activity toward the mycelial growth of grapevine trunk diseases (GTD)-associated fungi [16]. Some endophytic fungi can also promote plant growth by increasing plant access to nutrients (nitrogen, phosphorus, potassium, zinc, and iron), producing phytohormones, and increasing plant stress tolerance [14].…”

The Grapevine Microbiome to the Rescue: Implications for the Biocontrol of Trunk Diseases

“…Several recent studies have pointed to an interest in endophytic fungi as putative BCAs against GTD pathogens [ 89 , 90 ], but, unfortunately, there have not yet been any trials in plants to test their effectiveness. One of the most promising fungal BCAs against GTDs is the oomycete Pythium oligandrum , which is a frequent inhabitant of the grapevine root system from which different isolates have been obtained [ 80 , 91 ].…”

Draft Genome Sequence of Truncatella angustata (Anamorph) S358

“…It is common as an endophyte or pathogen of vascular plants in both temperate and tropical regions ( 3 , 4 ). It infects stems ( Vitis [ 5 , 6 ], Vaccinium [ 7 ]), leaves ( Rosa [ 8 ], Parthenocissus [ 3 ], Populus [ 9 ]), fruits ( Malus [ 10 ], Olea [ 11 ]), and roots ( Vitis [ 12 ]) and is also a candidate for biological control of plant diseases ( 9 , 12 ). In addition to plants, this fungus was also isolated from marine sponges ( 13 ), humans ( 4 ), and as a pathogen from insects ( 14 ).…”