Gao Pan, Qin Jiaxing, Li Delong, Zhou Shanyue
College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China.
The Key Lab of Integrated Crop Pests Management of Shandong Province, Qingdao Agricultural University, Qingdao, China.
PLoS One. 2018 Jan 10;13(1):e0190932. doi: 10.1371/journal.pone.0190932. eCollection 2018.
The fungal pathogen Botrytis cinerea causes gray mold disease on various hosts, which results in serious economic losses. Over the past several decades, many kinds of fungicides have been used to successfully control the disease. Meanwhile, the uses of fungicides lead to environmental pollution as well as a potential threat to the human health by the chemical residues in tomato fruit. Also, the gray mold disease is difficult to control with fungicides. Therefore, exploring alternative measures such as biological controls could be the best choice to control the disease and alleviate damages caused by fungicides. In this study, we isolated and identified a novel Pseudomonas strain termed as QBA5 from healthy tomato plant based on the morphological, biochemical characteristics and molecular detection. The antifungal activity assays revealed that, in the presence of QBA5, conidia germination, germ tube elongation and mycelial growth of B. cinerea were significantly inhibited. Most importantly, QBA5 exerted a significant preventive effectiveness against gray mold on tomato fruits and plants. The possible mechanism of QBA5 involved in the inhibition of B. cinerea was investigated. It revealed that the conidia plasma membrane of B. cinerea was severely damaged by QBA5. Further, four different antifungal compounds in the supernatant of QBA5 were separated by preparative high performance liquid chromatography (PHPLC). Overall, the data indicate that there is a considerable potential for QBA5 to reduce the damage caused by gray mold disease on tomato.
真菌病原体灰葡萄孢菌可在多种寄主上引发灰霉病，造成严重的经济损失。在过去几十年中，人们使用了多种杀菌剂来成功防治该病。与此同时，杀菌剂的使用导致了环境污染，并且番茄果实中的化学残留对人类健康构成潜在威胁。此外，灰霉病很难用杀菌剂进行防治。因此，探索诸如生物防治等替代措施可能是控制该病并减轻杀菌剂造成损害的最佳选择。在本研究中，我们基于形态学、生化特征和分子检测，从健康番茄植株中分离并鉴定出一种新型假单胞菌菌株，命名为QBA5。抗真菌活性测定表明，在QBA5存在的情况下，灰葡萄孢菌的分生孢子萌发、芽管伸长和菌丝生长均受到显著抑制。最重要的是，QBA5对番茄果实和植株上的灰霉病具有显著的预防效果。我们研究了QBA5抑制灰葡萄孢菌的可能机制。结果表明，QBA5严重破坏了灰葡萄孢菌分生孢子的质膜。此外，通过制备型高效液相色谱（PHPLC）分离出了QBA5上清液中的四种不同抗真菌化合物。总体而言，数据表明QBA5在减轻番茄灰霉病造成的损害方面具有相当大的潜力。
