ATP-binding cassette (ABC) transporters are membrane-bound proteins involved in the movement of various substrates, including drugs and insecticides, across the lipid membrane. Demonstration of the role of human ABC transporters in multidrug resistance has led to speculation that they might be an important mechanism controlling the fate of insecticides in insects. However, the role of ABC transporters in insects remains largely unknown. The small brown planthopper, Laodelphax striatellus Fallén, has developed resistance to most of the insecticides used for its control. Our goals were to identify the ABC transporters in La. striatellus and to examine their involvement in resistance mechanisms, using related strains resistant to chlorpyrifos, deltamethrin and imidacloprid, compared with the susceptible strain. Based on the transcriptome of La. striatellus, 40 full-length ABC transporters belonging to the ABCA-ABCH subfamilies were identified. Quantitative PCR revealed that over 20% of genes were significantly up-regulated in different resistant strains, and eight genes from the ABCB/C/D/G subfamilies were up-regulated in all three resistant strains, compared with the susceptible strain. Furthermore, synergism studies showed verapamil significantly enhanced insecticide toxicity in various resistant strains but not in the susceptible strain. These results suggest that ABC transporters might be involved in resistance to multiple insecticides in La. striatellus.

Background and Aims:Mitogen-activated protein kinases have been found to play essential roles in mediating biotic and abiotic stress responses in plants. Investigation of their possible involvement in grapevine resistance to biotic or abiotic stresses and of their development will be possible only through future functional genomics experiments of gain/loss of function in the grapevine. Methods and Results: We identified and re-annotated all 12 mitogen-activated protein kinases genes from the 12X V1 sequenced grapevine genome and re-nominated them according to international standards as VvMPK. All were validated by cloning their cDNA sequences through polymerase chain reaction amplification. Expression analysis of VvMPK genes using microarray analysis and quantitative real-time polymerase chain reaction demonstrated that all VvMPK genes are expressed during grapevine growth and development. Based on expression analysis of grapevine tissues and organs at several developmental stages, and of leaf tissues treated with Erysiphe necator (powdery mildew), salicylic acid, ethylene, hydrogen peroxide and drought, we identified for further functional characterisation several VvMPK candidate genes which might be involved in grapevine growth and development and in biotic and abiotic responses. Conclusions: We identified several grapevine MPK genes modulated at the transcriptional level in several stages of grapevine growth and development and during the response to development and environmental stresses. Significance of the Study: This is the first comprehensive experimental survey of the grapevine MPK gene family, which provides insights into their potential roles in regulating responses to biotic and abiotic stresses. Ongoing functional characterisation of important candidate VvMPK genes will assist unravelling their biological roles in grapevine.

Faecal samples from 1488 pigs were collected from six pig farms in Jiangsu province and Shanghai city, eastern China, stained by the modified acid-fast staining technique (MAFS) and observed by light and phase contrast microscopy to identify Cryptosporidium oocysts. A total of 178 (12%) positive animals were detected. Three randomly selected MAFS-positive samples from each farm were further analysed by reverse-transcription polymerase chain reaction (RT-PCR) using primers designed to amplify DNA fragments from the small subunit ribosomal RNA (SSU rRNA) gene. PCR products from two positive samples were sequenced. Phylogenetic analysis and a distances matrix generated from these sequences showed that the isolates belonged to the species C. parvum, and were most similar to the C. parvum'mouse' genotype. The identification of this C. parvum genotype in pigs has not been reported previously. These findings are discussed in the context of the epidemiology of Cryptosporidium on pig farms.

A full-length cDNA homologue of SOS1 (salt overly sensitive 1) was isolated from the salinity-tolerant species Chrysanthemum crassum and found to encode a Na(+) /H(+) antiporter, using degenerate PCR and RACE-PCR. The 3752-bp sequence comprised a 3438 bp open reading frame, encoding a 127-kDa protein with 12 transmembrane domains within its N terminal portion, and a hydrophilic cytoplasmic tail in its C-terminal portion. CcSOS1 appears to be a plasma membrane protein, and shares ∼62% identity at the peptide level with its Arabidopsis thaliana homologue. Expression of CcSOS1 in the roots of C. crassum was sensitive to salinity stress, while in the leaves CcSOS1 was down-regulated in the presence of abscisic acid. CcSOS1 transcript abundance was reduced in both roots and leaves of plants exposed to low temperature, while it was increased in leaves (but not in roots) after drought stress. CcSOS1 expression was not regulated in the presence of CaCl2 . A heterologous complementation assay in yeast suggested that CcSOS1 directs Na(+) efflux, mimicking the function of the endogenous NHA1 protein. Thus CcSOS1 appears to encode a salinity-inducible plasma membrane Na(+) /H(+) antiporter. This gene may be useful in transgenic approaches to improving the salinity tolerance of related ornamental species.

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