硝普钠抑制青枯菌的机制研究

Mechanism Study on Sodium Nitroprusside’s Inhibition of Ralstonia solanacearum

摘要: 硝普钠(Sodium Nitroprusside, SNP)作为一氧化氮(NO)的供体，已被广泛研究用于增强植物的抗逆性和抑制病原菌的生长。然而，其在防治烟草青枯病方面的效果尚未明确。本研究评估了SNP对烟草青枯病病原菌Ralstonia solanacearum的抗菌活性、形态、生物膜形成以及运动性的影响，以探讨SNP对烟草青枯病的作用及其机制。在体外实验中，SNP显著抑制了R. solanacearum的生长及细胞繁殖，随着SNP浓度的升高抑菌圈直径增加，1 mmol/L时抑菌圈增长率高达129.6%。并显著抑制了其生物膜形成和游动能力，最高减少82.53%和72.46%，在1 mmol/L时对青枯菌有明显趋避性，同时减少了R. solanacearum在烟草根部的定殖量。田间实验显示，施用SNP显著降低了烟草青枯病的发病率和病情指数，防效达到了57.71%。这些结果表明，SNP具有显著的抗菌效果，展示了其作为防治R. solanacearum引起的烟草青枯病的潜在应用价值。

Abstract: Sodium Nitroprusside (SNP), a nitric oxide (NO) donor, has been extensively investigated for its role in enhancing plant stress tolerance and inhibiting pathogen growth. However, its efficacy in controlling tobacco bacterial wilt caused by Ralstonia solanacearum remains to be elucidated. This study aimed to assess the antimicrobial activity, morphology, biofilm formation, and motility of SNP against R. solanacearum, thereby exploring its potential mechanism in combating tobacco bacterial wilt. In vitro experiments revealed that SNP significantly suppressed the growth and cell proliferation of R. solanacearum, with the diameter of the inhibition zone increasing proportionally to the SNP concentration, achieving a maximum increase of 129.6% at 1 mmol/L. Additionally, SNP markedly inhibited biofilm formation and swimming motility, with reductions of up to 82.53% and 72.46%, respectively. At a concentration of 1 mmol/L, SNP exhibited a pronounced repellent effect on R. solanacearum and reduced the colonization of the pathogen in tobacco roots. Field trials further demonstrated that SNP application significantly decreased the incidence and severity index of tobacco bacterial wilt, with a control efficacy of 57.71%. These findings suggest that SNP possesses significant antimicrobial properties and holds promise as a potential agent for controlling tobacco bacterial wilt caused by R. solanacearum.