Abstract：
The use of biological agents offers a sustainable alternative to chemical control in managing plant diseases. In this study, Bacillus velezensis IFST-221 was isolated from the rhizosphere of a healthy maize plant amidst a population showing severe disease symptoms. The investigation demonstrated a broad-spectrum antagonistic activity of IFST-221 against eight species of pathogenic ascomycetes and oomycetes, suggesting its potential utility in combating plant diseases like maize ear rot and cotton Verticillium wilt. Additionally, our study unveiled that IFST-221 has demonstrated significant plant growth-promoting properties, particularly in maize, cotton, tomato, and broccoli seedlings. This growth promotion was linked to its ability to produce indole-3-acetic acid, nitrogen fixation, phosphate and potassium solubilization, and biofilm formation in laboratory conditions. A complete genome sequencing of IFST-221 yielded a genome size of 3.858 M bp and a GC content of 46.71%. The genome analysis identified 3659 protein-coding genes, among which were nine secondary metabolite clusters with known antimicrobial properties. Additionally, three unknown compounds with potentially novel properties were also predicted from the genomic data. Genome mining also identified several key genes associated with plant growth regulation, colonization, and biofilm formation. These findings provide a compelling case for the application of B. velezensis IFST-221 in agricultural practices. The isolate\'s combined capabilities of plant growth promotion and antagonistic activity against common plant pathogens suggest its promise as an integrated biological agent in disease management and plant productivity enhancement.
摘要：
生物制剂的使用为管理植物病害提供了化学控制的可持续替代方案。在这项研究中,在表现出严重疾病症状的人群中，从健康玉米植物的根际中分离出VelezensisIFST-221。研究表明，IFST-221对8种致病性子囊菌和卵菌具有广谱拮抗活性，表明其在对抗玉米穗腐病和棉花黄萎病等植物病害方面的潜在用途。此外,我们的研究表明，IFST-221已经证明了显著的植物生长促进特性，特别是在玉米中，棉花,番茄,和西兰花幼苗。这种生长促进与它产生吲哚-3-乙酸的能力有关，固氮,磷酸盐和钾的溶解，在实验室条件下形成生物膜。IFST-221的完整基因组测序产生了3.858Mbp的基因组大小和46.71％的GC含量。基因组分析确定了3659个蛋白质编码基因，其中有9个具有已知抗菌特性的次级代谢产物簇。此外,还从基因组数据中预测了三种具有潜在新特性的未知化合物.基因组挖掘还确定了与植物生长调节相关的几个关键基因，殖民,和生物膜的形成。这些发现为VelezensisIFST-221在农业实践中的应用提供了令人信服的案例。分离株具有促进植物生长和对常见植物病原体的拮抗活性的综合能力，表明其有望成为疾病管理和提高植物生产力的综合生物制剂。
