Proteomics: a promising approach to study biotic interaction in legumes. A review

Summary During the 1990s and early 2000s, the genomes of different organisms have been completely sequenced. Nowadays, biological research is directed to understand gene expression and function. Proteomics, understood as protein biochemistry on an unprecedented and high-throughput scale, is becoming a promising and active approach in this post-genomic period. However, its application to plants is still rather limited as compared to other biological systems. After having referred to the most recent plant proteomic reviews, we focused on legume proteomics including studies with the model species Medicago truncatula. This review is aimed at providing to non-proteomic specialists a global overview of what might be expected in entering this field.     

Genetic diversity of the pea root pathogen Aphanomyces euteiches in Europe

The oomycete pathogen Aphanomyces euteiches causes root rot in various legume species. In this study we focused on A. euteiches causing root rot in pea (Pisum sativum), thereby being responsible for severe yield losses in pea production. We aimed to understand the genetic diversity of A. euteiches in Europe, covering a north-to-south gradient spanning from Sweden, Norway and Finland to the UK, France and Italy. A collection of 85 European A. euteiches strains was obtained, all isolated from infected pea roots from commercial vining pea cultivation fields. The strains were genotyped using 22 simple-sequence repeat markers. Multilocus genotypes were compiled and the genetic diversity between individual strains and population structure between countries was analysed. The population comprising strains from Italy was genetically different and did not share ancestry with any other population. Also, strains originating from Finland and the eastern parts of Sweden were found to be significantly different from the other populations, while strains from the rest of Europe were more closely related. A subset of 10 A. euteiches strains from four countries was further phenotyped on two susceptible pea genotypes, as well as on one genotype with partial resistance towards A. euteiches. All strains were pathogenic on all pea genotypes, but with varying levels of disease severity. No correlation between the genetic relatedness of strains and virulence levels was found. In summary, our study identified three genetically distinct groups of A. euteiches in Europe along a north-to-south gradient, indicating local pathogen differentiation.     

冬春季大口黑鲈溃疡症病原分离鉴定及病理形态学观察

目的 近年来，养殖大口黑鲈Micropterus salmoides在冬春季流行一种体表形成明显溃疡的疫病，本研究旨在明确其病因。方法 从眉山东坡区和洪雅县采集病料，采用病原学、病理学和分子生物学相结合的方法对患病鱼进行研究。结果 溃疡组织压片观察到大量直径10~30 μm、长丝状且分支较少的菌丝体；组织病理学上，肌纤坏死、溶解，炎性细胞浸润，病变组织中分布大量由上皮样细胞、纤维细胞及位于中央的菌丝体组成的霉菌性肉芽肿；六胺银染色(Periodic acid-silver metheramine，PASM)发现，霉菌性肉芽肿中央的菌丝体呈黑色。病变肌肉组织基于侵入丝囊霉菌Aphanomyces invadans ITS基因的特异性PCR检测为阳性。以葡糖糖/蛋白胨(Glucose and peotone，GP)琼脂分离培养得到的霉菌纯培养物(BW1、BW3)在灭菌池塘水过夜培养12 h后，形成原孢子囊，符合侵入丝囊霉菌属特征；两株分离霉菌ITS基因序列分析发现，其与侵入丝囊霉菌ITS基因的序列相似性分别为99.64%与99.46%，在系统发育树上与侵入丝囊霉菌聚类为一支。结论 确定大口黑鲈冬春季溃疡病是侵入丝囊霉菌感染所致。