Protective effect of Bacillus amyloliquefaciens against infections of Citrus aurantium seedlings by Phoma tracheiphila
Protective effect of Bacillus amyloliquefaciens against infections of Citrus aurantium seedlings by Phoma tracheiphila
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DOI：
10.1007/s11274-013-1471-5
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发表时间：
2014-02-01
影响因子：
4.1
通讯作者：
Limam, F.
中科院分区：
文献类型：
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作者：
Kalai-Grami, L.;Ben Slimane, I.;Limam, F.
从柑橘叶片中分离得到一株拮抗内生细菌TEB1，经16S rDNA测序鉴定为解淀粉芽孢杆菌（Bacillus olimyquefaciens），用于防治由有丝分裂真菌Phoma trachephila引起的柑橘幼苗恶性secco病。分离物TEB1在双重培养和扩散条件下均表现出良好的体外抗嗜气管假单胞菌活性。用TEB1细胞悬浮液浇灌的金莲幼苗，病害严重程度和发病率分别降低了53.61%和48.63%。接种365天后，用特异性引物进行PCR检测，接种对照植株的整个茎部均检测到冻干假单胞菌，而TEB1处理的幼苗未检测到扩增产物。对TEB1的分子分析显示，分别有负责风霉素和iturin脂肽生物合成的fendf和ituC基因扩增阳性。光学显微镜下观察发现，TEB1可使气管孢子萌发率降低55%，并对菌丝结构产生显著影响。数据表明，细菌产生的脂肽与真菌的细胞质膜相互作用，导致孔的形成。TEB1似乎是柑橘枯萎病生物防治的潜在候选基因。
Isolate TEB1 an antagonistic endophytic bacterium, obtained from citrus leaves and identified as Bacillus amyloliquefaciens by 16S rDNA sequencing, was used for the biological control of mal secco disease of Citrus aurantium seedlings caused by the mitosporic fungus Phoma tracheiphila. The isolate TEB1 exhibited a good in vitro activity against P. tracheiphila in dual cultures as well as with the well diffusion method. C. aurantium seedlings watered with a suspension of TEB1 cells showed a reduction of 53.61 and 48.63 % in disease severity and incidence, respectively. A PCR test with specific primers was performed 365 days after inoculation and P. tracheiphila was detected along the whole stem in inoculated control plant while no amplification product was obtained in TEB1 treated seedlings. Molecular analysis of TEB1 revealed a positive amplification of fenD and ituC genes responsible of the biosynthesis of fengycin and iturin lipopeptides, respectively. Moreover, observations by optical microscope showed that TEB1 reduced by 55 % the germination of P. tracheiphila conidia and exhibited a marked effect on mycelia structure. Data suggest that lipopeptides produced by the bacterium interact with the cytoplasmic membrane of the fungus causing pore formation. TEB1 appears a potential candidate for the biological control of citrus mal secco disease.