Enhanced resistance to citrus canker in transgenic sweet orange expressing the sarcotoxin IA gene
Enhanced resistance to citrus canker in transgenic sweet orange expressing the sarcotoxin IA gene
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DOI：
10.1007/s10658-017-1234-5
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发表时间：
2017-12-01
影响因子：
1.8
通讯作者：
Marques, Viviani V.
中科院分区：
文献类型：
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作者：
Kobayashi, Adilson K.;Vieira, Luiz Gonzaga E.;Marques, Viviani V.
柑桔溃疡病是由柑桔黄单胞菌（Xanthomonascitrisubp.）柑桔溃疡病（Xcc）是柑桔的一种严重病害，在世界上大部分柑桔产区均有报道。虽然甜橙对柑桔溃疡病有不同程度的田间抗性，但通常不足以提供对该病的充分控制。抗菌基因的异位表达是提高植物抗病性的潜在策略之一。先前的体外研究结果表明，从肉蝇（Sarcophaga peregrina）中分离的抗菌肽Sarcotoxin IA可以有效地控制不同的植物病原菌，包括Xcc。转“Pera”甜橙子（Citrus sinensis [L.] Osbeck）植物，其组成型表达与来自烟草的PR 1a信号肽融合的肌肉毒素IA肽，用于在细胞间隙中分泌。使用成熟外植体的薄切片，通过农杆菌介导的转化获得。通过渗透和喷雾接种Xcc，在转基因和非转基因植株的叶片中进行柑橘溃疡病抗性评价。与非转基因对照相比，转基因植物叶中的Xcc群体低达2个对数单位。在注射渗透或喷洒Xcc接种物后，非转化对照中溃疡病的发病率（> 10个病灶/cm（2））显著高于转基因植物（< 5个病灶/cm（2））。在甜橙子组织中积累的肉毒素IA肽对转基因植株的生长发育没有任何不良影响，表明这种方法适合于提供对柑橘溃疡病的抗性。
Citrus canker, caused by the bacterial pathogen Xanthomonas citri subp. Citri (Xcc), is a serious disease reported in most citrus-producing areas around the world. Although different levels of field resistance to citrus canker have been reported in sweet oranges, they are usually not sufficient to provide adequate control of the disease. Ectopic over-expression of antibacterial genes is one of the potential strategies to increase plant resistance to bacterial diseases. Previous in vitro results showed that sarcotoxin IA, an antimicrobial peptide isolated from the flesh fly (Sarcophaga peregrina), can be efficient to control different plant pathogenic bacteria, including Xcc. Transgenic "Pera" sweet orange (Citrus sinensis [L.] Osbeck) plants constitutively expressing the sarcotoxin IA peptide fused to the PR1a signal peptide from Nicotiana tabacum for secretion in the intercellular space were obtained by Agrobacterium-mediated transformation using thin sections of mature explants. Citrus canker resistance evaluation in leaves of transgenic and non-transgenic plants was performed through inoculations with Xcc by infiltration and spraying. The Xcc population was up to 2 log unit lower in leaves of the transgenic plants compared to those of non-transgenic controls. Incidence of canker lesions was significantly higher in non-transformed controls (> 10 lesions/cm(2)) than in the transgenic plants (< 5 lesions/cm(2)) after injection infiltration or spraying with Xcc inoculum. Accumulation of sarcotoxin IA peptide in sweet orange tissue did not cause any deleterious effects on the growth and development of the transgenic plants, indicating this approach is suitable to provide resistance to citrus canker.