College of Tobacco Science, Yunnan Agricultural University, Kunming, China.
China Tobacco Hebei Industrial Co. Ltd., Shijiazhuang, China.
Microbiol Spectr. 2024 Oct 3;12(10):e0014924. doi: 10.1128/spectrum.00149-24. Epub 2024 Aug 30.
Black shank disease in tobacco, caused by , can lead to yield losses of 30%-50% upon outbreak. Recently, biochar derived from agricultural waste has shown significant potential in controlling soil-borne diseases, though its mechanisms remain unclear. Over a 3-year observation period, we found that the incidence of black shank was significantly lower in plots amended with biochar compared with normal cultivation plots. To investigate the underlying mechanisms, we studied both the direct and indirect effects of biochar on black shank. Direct antifungal assays indicated that biochar reduced the total number of sporangia by 53.91%. Further pot experiments revealed a 62.34% reduction in the population in the soil following biochar application. Additionally, biochar application led to notable changes in soil physicochemical properties and microbial community composition. Microbial species analysis showed that biochar promoted the aggregation of beneficial microbes such as , , and . Functional predictions using the PICRUSt 2 software revealed that biochar enhances bacterial functions related to antimicrobial substance synthesis (Tetracycline biosynthesis), detoxification metabolism (D-arginine and D-ornithine metabolism, arginine and proline metabolism), and lipid and fatty acid metabolism (Lipopolysaccharide biosynthesis, fatty acid biosynthesis), while fungal functions showed no significant changes. This suggests that rhizosphere bacteria play a more prominent role in the suppression of black shank by biochar, a finding supported by partial least squares path modeling analysis. Therefore, we hypothesize that biochar not only directly inhibits growth but also regulates the composition of the rhizosphere microbial community, inducing the production of antimicrobial substances by rhizosphere bacteria, effectively preventing invasion.IMPORTANCEBlack shank, a global soil-borne fungal disease in tobacco, currently lacks effective control methods. Notably, biochar derived from agricultural waste has shown significant potential in controlling soil-borne diseases. Over a 3-year observation period, we found that plots amended with biochar had a significantly lower incidence of black shank compared with normal cultivation plots. However, the mechanisms of disease suppression remained unclear. Through antifungal assays and pot experiments, we discovered that tobacco-derived biochar can directly inhibit the growth of the pathogen. Additionally, biochar regulates the composition of the rhizosphere microbial community, inducing rhizosphere bacteria to produce antimicrobial substances, effectively preventing pathogen invasion. This discovery reveals both the direct and indirect mechanisms by which biochar suppresses black shank in tobacco. It provides a scientific basis for developing green control technologies for black shank and offers theoretical support for the application of biochar in managing soil-borne diseases in tobacco cultivation areas.
烟草黑胫病是由 引起的，发病时可导致烟草减产 30%-50%。最近，农业废弃物生物炭在防治土传病害方面表现出了巨大潜力，但其作用机制尚不清楚。在为期 3 年的观测期间，我们发现生物炭改良的种植区烟草黑胫病的发病率明显低于常规种植区。为了研究其作用机制，我们研究了生物炭对烟草黑胫病的直接和间接作用。直接抗真菌检测表明，生物炭可使孢子总数减少 53.91%。进一步的盆栽实验表明，生物炭处理后，土壤中的 数量减少了 62.34%。此外，生物炭的应用还导致土壤理化性质和微生物群落组成发生显著变化。微生物物种分析表明，生物炭促进了有益微生物的聚集，如 、 和 。使用 PICRUSt 2 软件进行功能预测显示，生物炭增强了与抗菌物质合成（四环素生物合成）、解毒代谢（D-精氨酸和 D-鸟氨酸代谢、精氨酸和脯氨酸代谢）和脂质及脂肪酸代谢（脂多糖生物合成、脂肪酸生物合成）相关的细菌功能，而真菌功能没有明显变化。这表明，根际细菌在生物炭抑制烟草黑胫病方面发挥了更重要的作用，这一发现得到了偏最小二乘法路径模型分析的支持。因此，我们假设生物炭不仅能直接抑制 的生长，还能调节根际微生物群落的组成，诱导根际细菌产生抗菌物质，从而有效阻止 的侵染。
烟草黑胫病是一种全球性的烟草土传真菌病害，目前尚无有效的防治方法。值得注意的是，农业废弃物生物炭在防治土传病害方面表现出巨大潜力。在为期 3 年的观测期间，我们发现，与常规种植区相比，生物炭改良的种植区烟草黑胫病的发病率显著降低。然而，其病害抑制机制尚不清楚。通过抗真菌检测和盆栽实验，我们发现烟草生物炭可以直接抑制病原菌的生长。此外，生物炭还可以调节根际微生物群落的组成，诱导根际细菌产生抗菌物质，有效阻止病原菌的侵染。这一发现揭示了生物炭抑制烟草黑胫病的直接和间接作用机制。它为开发烟草黑胫病绿色防治技术提供了科学依据，为生物炭在烟草种植区土传病害防治中的应用提供了理论支持。
