Suppression of Sclerotinia sclerotiorum by the Induction of Systemic Resistance and Regulation of Antioxidant Pathways in Tomato Using Fengycin Produced by Bacillus amyloliquefaciens FZB42
Suppression of Sclerotinia sclerotiorum by the Induction of Systemic Resistance and Regulation of Antioxidant Pathways in Tomato Using Fengycin Produced by Bacillus amyloliquefaciens FZB42
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DOI：
10.3390/biom9100613
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发表时间：
2019-10-01
期刊：
影响因子：
5.5
通讯作者：
Gao, Xuewen
中科院分区：
文献类型：
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作者：
Farzand, Ayaz;Moosa, Anam;Gao, Xuewen
芽孢杆菌脂肽对植物病原菌具有良好的生物防治活性。本研究旨在探索纯化的风霉素诱导番茄对核盘菌产生系统抗性的可能性。淀粉溶解芽孢杆菌FZB42及其突变体AK1S及其代谢产物在体外对核盘菌的菌丝有抑制作用。从一株AK1S突变体中分离纯化了一株风霉素，并用高效液相色谱和MALDI-TOF-MS对其进行了鉴定。扫描电子显微镜和透射电子显微镜显示真菌菌丝体结构变形。此外，与未经处理的对照相比，风霉素诱导核盘菌菌丝体中活性氧(ROS)的积累，并下调清除ROS的基因超氧化物歧化酶(SsSOD)、过氧化氢酶(SSPO)和过氧化氢酶(SsCAT1)的表达。此外，在温室实验中，与仅感染菌核菌的植株相比，风霉素处理的番茄植株的病变大小显著减小。此外，防御相关基因GST、SOD、PAL、HMGR和MPK3的转录调控在接种后48h出现最高表达高峰。然而，随后在96 HPI时，与仅用丰霉素处理的植株相比，在丰霉素+核盘菌处理的植株中，它们的表达降低。相反，PPO的表达呈线性增加，最高可达96HPI。
Lipopeptides from Bacillus species exhibit promising biological control activity against plant pathogens. This study aimed to explore the potential of purified fengycin to induce systemic resistance in tomato against Sclerotinia sclerotiorum. Bacillus amyloliquefaciens FZB42, its mutant AK1S, and their corresponding metabolites showed in vitro inhibition of S. sclerotiorum mycelium. Fengycin derived from an AK1S mutant was purified and identified through HPLC and MALDI-TOF-MS, respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed structural deformities in the fungal mycelium. Moreover, fengycin induced the accumulation of reactive oxygen species (ROS) in S. sclerotiorum mycelium and downregulated the expression of ROS-scavenging genes viz., superoxide dismutase (SsSOD1), peroxidase (SsPO), and catalase (SsCAT1) compared to the untreated control. Furthermore, the lesion size was dramatically reduced in fengycin-treated tomato plants compared to plants infected with S. sclerotiorum only in a greenhouse experiment. Additionally, the transcriptional regulation of defense-related genes GST, SOD, PAL, HMGR, and MPK3 showed the highest upsurge in expression at 48 h post-inoculation (hpi). However, their expression was subsequently decreased at 96 hpi in fengycin + S. sclerotiorum treatment compared to the plants treated with fengycin only. Conversely, the expression of PPO increased in a linear manner up to 96 hpi.