Aim:  To investigate the immunoprotection of three recombinant proteins derived from the Vibrio harveyi outer membrane proteins (OMPs) OmpK, glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) and their fusion OmpK–GAPDH as vaccine candidates from vibriosis of large yellow croaker (Pseudosciaena crocea). Methods:  The ompK gene, of which the leader sequence was omitted, was fused with the gapdh gene. Three recombinant proteins r‐OmpK, r‐GAPDH and r‐OmpK–GAPDH were expressed and purified. Western blots were carried out to detect the specificity of the antibodies raised against the recombinant proteins; Fish were immunized with recombinant proteins and challenged by native V. harveyi. The immunoresponse to the recombinant proteins were determined by ELISA and phagocytic activity assay. Conclusions:  The fusion protein r‐OmpK–GAPDH can afford greater protection against the wild V. harveyi than r‐OmpK or r‐GAPDH alone or their mixture in humoral and cellular immunity, indicating that OmpK and GAPDH could produce a synergistic immunoprotection against vibriosis of large yellow croaker (Pseudosciaena crocea) when fused into OmpK–GAPDH with a linker. Significance and Impact of the Study:  It has been realized that a multi‐component OMP antigen can induce a higher frequency of immune effectors than a single OMP. The results presented here bring forth a good suggestion for the subunit vaccine design based on the OMPs of gram‐negative pathogens.

Aims:  The aim of this study was to develop a sensitive real‐time polymerase chain reaction (PCR) assay for the rapid detection of Cladosporium fulvum in tomato leaves. Methods and Results:  Three PCR primer pairs were designed based on the nucleotide sequences of: (i) the internal transcribed spacer regions of ribosomal RNA; (ii) a microsatellite region amplified by the microsatellite primer M13; and (iii) the β‐tubulin gene of C. fulvum. Each primer pair amplified the expected target DNA fragment from geographically diverse isolates of C. fulvum. No PCR products were amplified with these primer pairs from DNA of other fungal species. Among the three pairs of primers, the primer pair CfF1/CfR1 developed based on the microsatellite region was the most sensitive. Using this sensitive primer pair, a real‐time PCR assay was developed to detect early infection of C. fulvum in tomato leaves. Significance and Impact of the Study:  DNA regions amplified by the microsatellite primer M13 have a high potential for developing highly sensitive species‐specific PCR primers for the detection of phytopathogenic fungi. The real‐time PCR assay developed in this study is useful in monitoring early infection of C. fulvum, and can help growers make timely decisions on fungicide application.

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