A novel serine protease, Sep1, from Bacillus firmus DS-1 has nematicidal activity and degrades multiple intestinal-associated nematode proteins.
A novel serine protease, Sep1, from Bacillus firmus DS-1 has nematicidal activity and degrades multiple intestinal-associated nematode proteins.
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来自坚强芽孢杆菌 DS-1 的新型丝氨酸蛋白酶 Sep1 具有杀线虫活性并降解多种肠道相关线虫蛋白
DOI：
10.1038/srep25012
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发表时间：
2016-04-27
影响因子：
4.6
通讯作者：
Peng D
中科院分区：
文献类型：
--
作者：
Geng C;Nie X;Tang Z;Zhang Y;Lin J;Sun M;Peng D
植物寄生线虫对农业生产造成严重危害。硬芽孢杆菌对PPNs具有良好的控制作用，并已作为商业杀线虫剂生产。然而，其杀线虫因子和机制尚不清楚。在本研究中，我们发现僵杆菌DS-1菌株对不知名甜根线虫和大豆囊线虫具有高毒力。我们对DS-1的全基因组进行了测序，并确定了多个潜在的毒力因子。然后，我们专注于一种名为Sep1的肽酶S8超家族蛋白，并证明它对秀丽隐杆线虫和隐杆线虫具有毒性。Sep1蛋白具有丝氨酸蛋白酶活性，可降解线虫肠道组织。因此，芽孢杆菌Sep1蛋白酶是一种具有抗根结线虫活性的新型生物防治因子。然后，我们以秀丽隐杆线虫为模型来阐明Sep1的杀线虫机制，结果表明Sep1可以降解多种肠道和角质层相关蛋白，并破坏宿主的物理屏障。在我们的研究中获得的知识将导致更好地理解B. firmus对抗PPNs的机制，并将有助于开发新的生物制剂，以提高控制PPNs的功效。
Plant-parasitic nematodes (PPNs) cause serious harm to agricultural production. Bacillus firmus shows excellent control of PPNs and has been produced as a commercial nematicide. However, its nematicidal factors and mechanisms are still unknown. In this study, we showed that B. firmus strain DS-1 has high toxicity against Meloidogyne incognita and soybean cyst nematode. We sequenced the whole genome of DS-1 and identified multiple potential virulence factors. We then focused on a peptidase S8 superfamily protein called Sep1 and demonstrated that it had toxicity against the nematodes Caenorhabditis elegans and M. incognita. The Sep1 protein exhibited serine protease activity and degraded the intestinal tissues of nematodes. Thus, the Sep1 protease of B. firmus is a novel biocontrol factor with activity against a root-knot nematode. We then used C. elegans as a model to elucidate the nematicidal mechanism of Sep1 and the results showed that Sep1 could degrade multiple intestinal and cuticle-associated proteins and destroyed host physical barriers. The knowledge gained in our study will lead to a better understanding of the mechanisms of B. firmus against PPNs and will aid in the development of novel bio-agents with increased efficacy for controlling PPNs.