Endophytes of Brazilian Medicinal Plants With Activity Against Phytopathogens.
Endophytes of Brazilian Medicinal Plants With Activity Against Phytopathogens.
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DOI：
10.3389/fmicb.2021.714750
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发表时间：
2021
影响因子：
5.2
通讯作者：
Glienke C
中科院分区：
文献类型：
--
作者：
Iantas J;Savi DC;Schibelbein RDS;Noriler SA;Assad BM;Dilarri G;Ferreira H;Rohr J;Thorson JS;Shaaban KA;Glienke C
由植物病原体引起的植物病害是造成世界范围内重大作物损失的原因。抗性诱导和生物防治因其巨大的潜力而在农业上得到了开发。在这项研究中，我们调查了内生真菌的叶片和叶柄的药用植物Vochysia divergens和Stryphnodendron adstringens位于两个地区的高多样性在巴西，潘塔纳尔，塞拉多，分别抗菌潜力。我们回收了1，304个真菌分离株，并根据培养物的特征，将其分配到159个表型。选择一种分离株作为每种表型的代表，并研究其对植物病原体的抗菌活性。通过DNA序列测定和系统发育分析，筛选出生物活性较好的菌株。从159个代表性菌株中筛选出12株内生真菌提取物对黄瓜炭疽菌菌丝生长抑制率≥40%的菌株，进行了抑菌活性的研究。测定了各提取物对柑橘类病原菌C.柑橘叶点霉（Phyllosticta citricarpa）和柑橘黄单胞菌（Xanthomonas citri subsp.）柑橘和玉米病原体禾谷镰刀菌（Fusarium graminearum）。对C.柑橘假褐壳菌CMRP 4328（IG：83%，MIC：40 μg/mL）和伏赤壳菌CMRP 4322（IG：75%，MIC：1 μg/mL）的提取物对花后落果症状也有抑制作用。该提取物对柑桔实腐病菌菌丝生长有较好的抑制作用，并能减少柑桔叶片中分生孢子的产生。在表现出活性的菌株中，透孔菌属是最常见的，包括新种D。Cerradensis在这项研究中描述。此外，对活性较高的内生菌提取物进行了高效液相色谱、紫外检测、质谱和薄层色谱分析，结果表明，D. vochysiae CMRP 4322和P. stromaticum CMRP 4328是生产新的生物活性天然产物的有希望的菌株。本文报道了药用植物内生真菌产生具有抗植物病原真菌和细菌生物活性的次生代谢产物的能力。新种D. cerradensis，加强了在巴西发现的药用植物宿主具有生物技术潜力的各种真菌的能力。
Plant diseases caused by phytopathogens are responsible for significant crop losses worldwide. Resistance induction and biological control have been exploited in agriculture due to their enormous potential. In this study, we investigated the antimicrobial potential of endophytic fungi of leaves and petioles of medicinal plants Vochysia divergens and Stryphnodendron adstringens located in two regions of high diversity in Brazil, Pantanal, and Cerrado, respectively. We recovered 1,304 fungal isolates and based on the characteristics of the culture, were assigned to 159 phenotypes. One isolate was selected as representative of each phenotype and studied for antimicrobial activity against phytopathogens. Isolates with better biological activities were identified based on DNA sequences and phylogenetic analyzes. Among the 159 representative isolates, extracts from 12 endophytes that inhibited the mycelial growth (IG) of Colletotrichum abscissum (≥40%) were selected to expand the antimicrobial analysis. The minimum inhibitory concentrations (MIC) of the extracts were determined against citrus pathogens, C. abscissum, Phyllosticta citricarpa and Xanthomonas citri subsp. citri and the maize pathogen Fusarium graminearum. The highest activity against C. abscissum were from extracts of Pseudofusicoccum stromaticum CMRP4328 (IG: 83% and MIC: 40 μg/mL) and Diaporthe vochysiae CMRP4322 (IG: 75% and MIC: 1 μg/mL), both extracts also inhibited the development of post-bloom fruit drop symptoms in citrus flowers. The extracts were promising in inhibiting the mycelial growth of P. citricarpa and reducing the production of pycnidia in citrus leaves. Among the isolates that showed activity, the genus Diaporthe was the most common, including the new species D. cerradensis described in this study. In addition, high performance liquid chromatography, UV detection, and mass spectrometry and thin layer chromatography analyzes of extracts produced by endophytes that showed high activity, indicated D. vochysiae CMRP4322 and P. stromaticum CMRP4328 as promising strains that produce new bioactive natural products. We report here the capacity of endophytic fungi of medicinal plants to produce secondary metabolites with biological activities against phytopathogenic fungi and bacteria. The description of the new species D. cerradensis, reinforces the ability of medicinal plants found in Brazil to host a diverse group of fungi with biotechnological potential.