Recently, in vitro assays have been used to study biofilm formation by Xanthomonas citri pv. viticola (Xcv), the causal agent of grapevine bacterial canker, one of the most important grapevine diseases in the Northeast region of Brazil. Currently, the management of grapevine bacterial canker is based on preventive control by copper fungicides, highlighting the need to discover new bioactive compounds that can be used in disease management programs. Thus, this study reports the first evaluation of the effects of crude aqueous extracts of Caatinga plants on planktonic growth and biofilm formation of Xcv. Crude aqueous extracts of twelve plants collected in Catimbau Valley, Brazil, were evaluated in vitro against four strains of Xcv to determine the antibacterial and antibiofilm activities of the plants. The experiments were conducted in 96-well polystyrene microtiter plates. The results were subjected to Dunnett’s test (P < 0.05) to determine the significant differences between the tested extracts and the control treatment, which included sterile distilled water (SDW). Only the extracts obtained from Homalolepis ferruginea leaf showed antibiofilm and antibacterial activity against all strains; this extract reduced biofilm formation and planktonic growth by up to 54.6% and 60.2%, respectively, making H. ferruginea a source of promising biomolecules for the management of grapevine bacterial canker.

中文翻译：

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Caatinga 生物群落植物提取物影响 Xanthomonas citri pv. 的浮游生长和生物膜形成。葡萄科

最近，体外试验已被用于研究柑橘黄单胞菌的生物膜形成。viticola (Xcv)，葡萄细菌性溃疡病的病原体，是巴西东北部地区最重要的葡萄病害之一。目前，葡萄藤细菌溃疡病的管理基于铜杀菌剂的预防控制，突出了发现可用于疾病管理计划的新生物活性化合物的必要性。因此，本研究首次评估了 Caatinga 植物的粗水提取物对 Xcv 浮游生长和生物膜形成的影响。在巴西 Catimbau Valley 收集的 12 种植物的粗水提取物在体外针对四种 Xcv 菌株进行评估，以确定植物的抗菌和抗生物膜活性。实验在 96 孔聚苯乙烯微量滴定板中进行。结果经过 Dunnett 检验 (P < 0.05)，以确定受试提取物与对照处理（包括无菌蒸馏水 (SDW)）之间的显着差异。只有从 Homalolepis ferruginea 叶中提取的提取物对所有菌株均表现出抗生物膜和抗菌活性；这种提取物使生物膜形成和浮游生物生长分别减少了 54.6% 和 60.2%，使 H. ferruginea 成为治疗葡萄细菌溃疡病的有希望的生物分子的来源。只有从 Homalolepis ferruginea 叶中提取的提取物对所有菌株均表现出抗生物膜和抗菌活性；这种提取物使生物膜形成和浮游生物生长分别减少了 54.6% 和 60.2%，使 H. ferruginea 成为治疗葡萄细菌溃疡病的有希望的生物分子的来源。只有从 Homalolepis ferruginea 叶中提取的提取物对所有菌株均表现出抗生物膜和抗菌活性；这种提取物使生物膜形成和浮游生物生长分别减少了 54.6% 和 60.2%，使 H. ferruginea 成为治疗葡萄细菌溃疡病的有希望的生物分子的来源。