Li Xiaojuan, Zhang Miaoyi, Qi Dengfeng, Zhou Dengbo, Qi Chunlin, Li Chunyu, Liu Siwen, Xiang Dandan, Zhang Lu, Xie Jianghui, Wang Wei
Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Science, Hainan Normal University, Haikou, China.
Front Microbiol. 2021 Sep 17;12:735732. doi: 10.3389/fmicb.2021.735732. eCollection 2021.
Strawberry is a very popular fruit with a special taste, color, and nutritional value. Anthracnose caused by severely limits fruit shelf life during post-harvest storage. Use of traditional chemical fungicides leads to serious environment pollution and threatens food safety. Biocontrol is considered as a promising strategy to manage the post-harvest fruit diseases. Here, strain QN1NO-4 isolated from noni ( L.) fruit exhibited a high antifungal activity against . Based on its physicochemical profiles and phylogenetic tree of the 16S sequence, strain QN1NO-4 belonged to the genus . The average nucleotide identity (ANI) calculated by comparing two standard strain genomes was below 95-96%, suggesting that the strain might be a novel species of the genus and named as sp. QN1NO-4. Its extract effectively reduced the incidence of strawberry anthracnose of harvested fruit. Fruit weight and TSS contents were also maintained significantly. The antifungal mechanism assays indicated that the extract of the test antagonist inhibited mycelial growth and spore germination of Cells of strain QN1NO-4 demonstrated the cytoplasmic heterogeneity, disappeared organelles, and ruptured ultrastructure. Notably, the strain extract also had a broad-spectrum antifungal activity. Compared with the whole genome of strain QN1NO-4, several functional gene clusters involved in the biosynthesis of active secondary metabolites were observed. Fifteen compounds were identified by gas chromatography-mass spectrometry (GC-MS). Hence, the fruit endophyte sp. QN1NO-4 is a potential bio-agent identified for the management of post-harvest disease of strawberry fruit.
草莓是一种非常受欢迎的水果，具有独特的味道、颜色和营养价值。由[具体病原菌]引起的炭疽病严重限制了果实采后贮藏期间的货架期。使用传统化学杀菌剂会导致严重的环境污染并威胁食品安全。生物防治被认为是管理采后果实病害的一种有前景的策略。在此，从诺丽果（[诺丽的学名]）中分离出的菌株QN1NO - 4对[具体病原菌]表现出高抗真菌活性。基于其理化特征和16S序列的系统发育树，菌株QN1NO - 4属于[具体属名]属。通过比较两个标准菌株基因组计算的平均核苷酸同一性（ANI）低于95 - 96%，表明该菌株可能是[具体属名]属的一个新物种，并命名为[具体属名] sp. QN1NO - 4。其提取物有效降低了采后草莓果实炭疽病的发病率。果实重量和总可溶性固形物含量也得到了显著维持。抗真菌机制分析表明，测试拮抗菌的提取物抑制了[具体病原菌]的菌丝生长和孢子萌发。菌株QN1NO - 4的细胞表现出细胞质异质性、细胞器消失和超微结构破裂。值得注意的是，该菌株提取物还具有广谱抗真菌活性。与菌株QN1NO - 4的全基因组相比，观察到几个参与活性次生代谢物生物合成的功能基因簇。通过气相色谱 - 质谱联用（GC - MS）鉴定出15种化合物。因此，果实内生菌[具体属名] sp. QN1NO - 4是一种被鉴定用于管理草莓果实采后病害的潜在生物制剂。
