向日葵柄锈菌效应蛋白的预测及筛选

向日葵柄锈菌（Puccinia helianthi Schw.）引发向日葵锈病，对生产具有破坏性。为深入了解锈菌效应蛋白，研究病原与寄主的互作机理，在获得向日葵柄锈菌分泌蛋白组的基础上，利用生物信息学软件预测及分析向日葵柄锈菌效应蛋白，采用qRT-PCR检测其中7个候选效应蛋白基因在接种叶片中的相对表达量。结果表明：在供试的900个锈菌的分泌蛋白中预测到候选效应蛋白497个。基因特征分析显示，开放阅读框长度在200～399 bp之间的最多；信号肽长度集中在16～27个氨基酸残基（占92.96%）；信号肽氨基酸组成中亮氨酸出现频率最高，其次为丙氨酸、异亮氨酸；信号肽识别位点以SpⅠ型为主。本研究获得了7个向日葵柄锈菌的效应蛋白，qRT-PCR检测表明柄锈菌接种向日葵叶片后，与纯孢子相比，这7个效应蛋白编码基因均上调表达，说明其参与了锈菌侵染向日葵的过程。

Prediction and screening of effector proteins of Puccinia helianthi

Puccinia helianthi Schw. is an important pathogenic fungi for sunflower. To better understand their pathogen-plant interacting, rust-effectors were predicted from secreted proteome of this sunflower rust pathogen. Among 900 secretory proteins, 497 candidate effectors were predicted. Protein characteristics showed that their length of open reading frame was mostly between 200 and 399 bp. Length of signal peptides were mainly （92.96%） between 16 and 27 amino acids.The most frequent amino acid in signal peptides was leucine, followed by alanine and isoleucine. Signal peptide recognition sites were mainly SpⅠ type. qRT-PCR on 7 candidate effector-encoding genes in inoculated leaves showed that they were up-regulated compared with pure spores （control）, indicating their involving in pathogenesis of sunflower rust.