Biodiversity of Vitis vinifera endophytes in conventional and biodynamic vineyard

Plants are permanently exposed to biotic and abiotic stress and have therefore developed intricate resistance mechanisms, consequently. These include the presence of microbial endophytes, which can promote plant growth and ensure better resilience against unfavourable conditions. These microorganisms colonising plant tissues can directly affect plant growth by producing phytohormones, antioxidants, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, or indirectly by the production of siderophores and antifungal agents. To the best of our knowledge, this is the first study devoted to assessing bacterial endophyte diversity and their plant growth-promoting properties in two ut-terly distinct vineyards in view of agricultural management (conventional, biodynamic) in the Czech Republic. With these different agricultural approaches, we hypothesised different numerical representations of bacterial endophytes acquired from vine shoots and leaves, which was not proved (P = 0.743, F = 0.129). A total of 470 distinct bacterial en-dophytes were isolated from the Vitis vinifera plants from the conventional and biodynamic vineyard and from which over 80% were identified by the matrix-assisted laser desorption-time-of-flight mass spectrometry (MALDI-TOF MS). In both vineyards, the dominant bacterial genus was Bacillus, followed by Pantoea, Pseudomonas and Staphylococcus. Plant-promoting endophyte properties varied with respect to the season and type of vineyard. The ability to produce indole-3-acetic acid (IAA) and ACC deaminase was higher in the biodynamic vineyard, in comparison with antioxidant activity, which was found in a higher proportion in isolates from the conventional vineyard.