Petrillo Claudia, Castaldi Stefany, Lanzilli Mariamichela, Selci Matteo, Cordone Angelina, Giovannelli Donato, Isticato Rachele
Department of Biology, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Naples, Italy.
Institute of Biomolecular Chemistry (ICB), CNR, Pozzuoli, Italy.
Front Microbiol. 2021 Sep 13;12:715678. doi: 10.3389/fmicb.2021.715678. eCollection 2021.
Massive application of chemical fertilizers and pesticides has been the main strategy used to cope with the rising crop demands in the last decades. The indiscriminate use of chemicals while providing a temporary solution to food demand has led to a decrease in crop productivity and an increase in the environmental impact of modern agriculture. A sustainable alternative to the use of agrochemicals is the use of microorganisms naturally capable of enhancing plant growth and protecting crops from pests known as Plant-Growth-Promoting Bacteria (PGPB). Aim of the present study was to isolate and characterize PGPB from salt-pans sand samples with activities associated to plant fitness increase. To survive high salinity, salt-tolerant microbes produce a broad range of compounds with heterogeneous biological activities that are potentially beneficial for plant growth. A total of 20 halophilic spore-forming bacteria have been screened for phyto-beneficial traits and compared with other two members of genus recently isolated from the rhizosphere of the same collection site and characterized as potential biocontrol agents. Whole-genome analysis on seven selected strains confirmed the presence of numerous gene clusters with PGP and biocontrol functions and of novel secondary-metabolite biosynthetic genes, which could exert beneficial impacts on plant growth and protection. The predicted biocontrol potential was confirmed in dual culture assays against several phytopathogenic fungi and bacteria. Interestingly, the presence of predicted gene clusters with known biocontrol functions in some of the isolates was not predictive of the results, supporting the need of combining laboratory assays and genome mining in PGPB identification for future applications.
在过去几十年里，大量施用化肥和农药一直是应对不断增长的作物需求的主要策略。在提供粮食需求的临时解决方案的同时，不加区分地使用化学品导致了作物生产力的下降以及现代农业对环境影响的增加。一种可持续替代农用化学品的方法是使用天然能够促进植物生长并保护作物免受害虫侵害的微生物，即植物促生细菌（PGPB）。本研究的目的是从盐田砂样中分离和鉴定具有与提高植物适应性相关活性的PGPB。为了在高盐度环境中生存，耐盐微生物会产生一系列具有不同生物活性的化合物，这些化合物可能对植物生长有益。总共筛选了20株嗜盐芽孢杆菌的植物有益特性，并与最近从同一采集地点的根际分离出来并被鉴定为潜在生物防治剂的该属的其他两个成员进行了比较。对七个选定菌株的全基因组分析证实了存在许多具有植物促生和生物防治功能的基因簇以及新的次生代谢物生物合成基因，这些基因可能对植物生长和保护产生有益影响。在针对几种植物病原真菌和细菌的共培养试验中证实了预测的生物防治潜力。有趣的是，一些分离物中具有已知生物防治功能的预测基因簇的存在并不能预测结果，这支持了在未来应用的PGPB鉴定中需要将实验室检测和基因组挖掘相结合的观点。
