de Carvalho Mayra C da C G, Costa Nascimento Leandro, Darben Luana M, Polizel-Podanosqui Adriana M, Lopes-Caitar Valéria S, Qi Mingsheng, Rocha Carolina S, Carazzolle Marcelo Falsarella, Kuwahara Márcia K, Pereira Goncalo A G, Abdelnoor Ricardo V, Whitham Steven A, Marcelino-Guimarães Francismar C
Universidade Estadual do Norte do Paraná, Bandeirantes, Paraná, CEP 86360-000, Brazil.
Laboratório de Genômica e Expressão (LGE) - Instituto de Biologia - Universidade Estadual de Campinas, Campinas, São Paulo, CEP 13083-862, Brazil.
Mol Plant Pathol. 2017 Apr;18(3):363-377. doi: 10.1111/mpp.12405. Epub 2016 Jun 9.
Asian soybean rust (ASR), caused by the obligate biotrophic fungus Phakopsora pachyrhizi, can cause losses greater than 80%. Despite its economic importance, there is no soybean cultivar with durable ASR resistance. In addition, the P. pachyrhizi genome is not yet available. However, the availability of other rust genomes, as well as the development of sample enrichment strategies and bioinformatics tools, has improved our knowledge of the ASR secretome and its potential effectors. In this context, we used a combination of laser capture microdissection (LCM), RNAseq and a bioinformatics pipeline to identify a total of 36 350 P. pachyrhizi contigs expressed in planta and a predicted secretome of 851 proteins. Some of the predicted secreted proteins had characteristics of candidate effectors: small size, cysteine rich, do not contain PFAM domains (except those associated with pathogenicity) and strongly expressed in planta. A comparative analysis of the predicted secreted proteins present in Pucciniales species identified new members of soybean rust and new Pucciniales- or P. pachyrhizi-specific families (tribes). Members of some families were strongly up-regulated during early infection, starting with initial infection through haustorium formation. Effector candidates selected from two of these families were able to suppress immunity in transient assays, and were localized in the plant cytoplasm and nuclei. These experiments support our bioinformatics predictions and show that these families contain members that have functions consistent with P. pachyrhizi effectors.
亚洲大豆锈病（ASR）由专性活体营养型真菌大豆锈菌（Phakopsora pachyrhizi）引起，可造成超过80%的损失。尽管其具有经济重要性，但尚无具有持久抗ASR能力的大豆品种。此外，大豆锈菌的基因组尚未可得。然而，其他锈菌基因组的可得性，以及样本富集策略和生物信息学工具的发展，增进了我们对ASR分泌蛋白组及其潜在效应子的了解。在此背景下，我们结合激光捕获显微切割（LCM）、RNA测序和生物信息学流程，共鉴定出36350个在植物体内表达的大豆锈菌重叠群以及一个由851种蛋白质组成的预测分泌蛋白组。一些预测的分泌蛋白具有候选效应子的特征：体积小、富含半胱氨酸、不包含PFAM结构域（与致病性相关的结构域除外）且在植物体内强烈表达。对柄锈菌目物种中存在的预测分泌蛋白进行的比较分析，鉴定出了大豆锈菌的新成员以及柄锈菌目或大豆锈菌特有的新家族（族）。一些家族的成员在早期感染期间，从最初感染到吸器形成开始，均强烈上调表达。从其中两个家族中选出的候选效应子能够在瞬时试验中抑制免疫反应，且定位于植物细胞质和细胞核中。这些实验支持了我们的生物信息学预测，并表明这些家族包含功能与大豆锈菌效应子一致的成员。
