RNA-seq analysis for soybean cyst nematode resistance of Glycine soja(wild soybean)

To explore genetic resource of wild soybean(Glycine soia. L), RNA-seq was used to investigate cyst nematode resistance of G. soja. Root transcriptome expressions were profiled at 9, 15 and 20 d post inoculation(DPI) in resistant and susceptible G. soja to SCN(soybean cyst nematode). A total of 1,594 differentially expressed genes(DEGs) were identified in roots infected by SCN compared with non-infected roots. In the resistant accession, 619, 65, and 8 DEGs were detected at 9, 15, and 20 DPI, respectively, while 327, 460 and 115 DEGs were detected at the same sampling point of susceptible accessions. DEGs were enriched in peroxidase gene sets which were involved in response to oxidative stress and oxidation reduction. Two gene families, ZIM transcription factor and WRKY transcription factor were enriched. WRKY transcription factor was only enriched in resistant accession. Moreover, gene expressions of 9 DEGs were validated by qRT-PCR. XLOC_023202, an unknown protein was up regulated more than 5 fold at 9 and 15 DPI in the resistant accession. These results provided an atlas of gene expressions of G. soja in response to SCN infection, and identified candidate DEGs for future research.

Microdissection of chromosome 7B of common wheat and cloning of low-copy specific DNA sequences

The 7B chromosome of common wheat was microdissected from pollen mother cells of the 7B monosomic line of common wheat cv. Chinese Spring (CS). After proteinase K and DNA topoisomerase Ⅰtreatments, the isolated chromosomes were subjected to 1—3 rounds of DOPPCR amplification, which produced continuous DNA fragments ranging from 150 to 700 bp. Genomic Southern hybridization confirmed that the PCR products were originated from the wheat genome. Cloning of portion ( 】 200 bp) of the 3rd round DOP-PCR products (50 μL) could generate about 20 000 recombinant clones. Characterization of 50 randomly chosen clones indicated that 21 clones produced discrete PCR products with the size of 240—600 bp. Dot-blot hybridization showed that among the 21 clones, 11 (～ 55%) were of low-copy nature while 10 (～45%) were repetitive. Southern hybridization with the complete set of the CS 'nullisomic-tetrasomic (NT)' lines demonstrated that all the 6 low-copy clones were specific to either chromosome 7B or the 7th