Overexpression of a Modified Plant Thionin Enhances Disease Resistance to Citrus Canker and Huanglongbing (HLB).
Overexpression of a Modified Plant Thionin Enhances Disease Resistance to Citrus Canker and Huanglongbing (HLB).
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改良植物的过表达硫宁增强了对柑橘溃疡和黄隆（HLB）的抗病性。
DOI：
10.3389/fpls.2016.01078
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发表时间：
2016
影响因子：
5.6
通讯作者：
Gupta G
中科院分区：
文献类型：
--
作者：
Hao G;Stover E;Gupta G
黄龙病（HLB或柑橘绿化病）是由亚洲柑桔黄龙病菌（Las）引起的一种严重危害美国柑橘产业的病害。目前还没有经过证实的消除HLB病害的策略，也没有鉴定出具有强HLB抗性的栽培品种。柑橘溃疡病也是一种与细菌病原体（柑橘黄单胞菌）相关的经济上重要的疾病。在这项研究中，我们的特点是内源性柑橘硫堇，并研究其在不同的柑橘组织中的表达。由于没有HLB抗性的柑橘品种已被确定，我们试图开发柑橘HLB和柑橘溃疡病通过过表达的修饰植物硫堇。为了提高植物的抗病性，我们对植物硫素基因进行了改造和合成，并将其克隆到双元载体pBinPlus/ARS中。然后将该构建体引入农杆菌菌株EHA 105中用于柑橘转化。通过农杆菌介导的转化产生表达修饰的植物硫堇的转基因Carrizo植物。通过分子分析证实了转化成功和转基因表达。表达修饰的硫素基因的转基因Carrizo植物用X.与非转基因植物相比，证明了在一定浓度范围内的Citri 3213以及溃疡症状的显著减轻和细菌生长的减少。此外，通过嫁接接种用HLB攻击转基因柑橘植物。我们的研究结果表明，转基因Carrizo的根与对照植物相比，降低了Las滴度，减少接穗Las滴度嫁接接种后12个月。这些数据提供了工程柑橘疾病的HLB和溃疡病的抗性的承诺。
Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the US citrus industry. There are no proven strategies to eliminate HLB disease and no cultivar has been identified with strong HLB resistance. Citrus canker is also an economically important disease associated with a bacterial pathogen (Xanthomonas citri). In this study, we characterized endogenous citrus thionins and investigated their expression in different citrus tissues. Since no HLB-resistant citrus cultivars have been identified, we attempted to develop citrus resistant to both HLB and citrus canker through overexpression of a modified plant thionin. To improve effectiveness for disease resistance, we modified and synthesized the sequence encoding a plant thionin and cloned into the binary vector pBinPlus/ARS. The construct was then introduced into Agrobacterium strain EHA105 for citrus transformation. Transgenic Carrizo plants expressing the modified plant thionin were generated by Agrobacterium-mediated transformation. Successful transformation and transgene gene expression was confirmed by molecular analysis. Transgenic Carrizo plants expressing the modified thionin gene were challenged with X. citri 3213 at a range of concentrations, and a significant reduction in canker symptoms and a decrease in bacterial growth were demonstrated compared to nontransgenic plants. Furthermore, the transgenic citrus plants were challenged with HLB via graft inoculation. Our results showed significant Las titer reduction in roots of transgenic Carrizo compared with control plants and reduced scion Las titer 12 months after graft inoculation. These data provide promise for engineering citrus disease resistance against HLB and canker.