To produce transgenic cucumber expressing Nit gene coffering abiotic resistance, the cotyledonary-node explants of cucumber (cv. Eunsung) were inoculated with A. tumefaciens transformed with pPZP211 or pCAMBIA2300 carrying Nit gene, that has cis-acting element involved in resistance to various abiotic environmental stresses. After co-cultivation, the procedures of selection, shoot initiation, shoot elongation, and plant regeneration were followed by cotyledonary-node transformation method (CTM, Jang et al. 2011). The putative transgenic plants were selected when shoots were grown to a length greater than 3 cm from the cotyledonary-node explants on selection medium supplemented with 100 mg/L paromomycin as a selectable agent. The confirmation of transgenic cucumber was based on the genomic PCR, Southern blot analysis, RT-PCR, and Northern blot analysis. A 105 shoots (4.12%) selected from the selection mediums were obtained from 2,547 explants inoculated. Of them, putative transgenic plants were only confirmed with 45 plants (1.77%) by genomic PCR analysis. Transgenic plants showed that the Nit genes integrated into each genome of 39 plants (1.53%) by Southern blot analysis, and the expression of gene integrated into cucumber genome was only confirmed at 6 plants (0.24%) by RT-PCR and Northern blot analysis. These results lead us to speculate that the genes were successfully integrated and expressed in each genome of transgenic cucumber.

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT We analyzed the transcriptional profile of the Xoo infected bbr1 mutant using a commercial rice gene chip containing 51,279 transcripts. Microarray revealed 92 genes with increased levels of expression and 22 genes with decreased levels of expression in bbr1. Some of the differentially expressed genes were validated by qRT-PCR. Higher expression of defense-related genes and AP2 domain containing transcription factors along with lower expression of reactive oxygen scavenging enzymes may be responsible for defense signaling in the bbr1 upon Xoo infection. The putative target genes of AP2 domain containing transcription factors also showed differential gene expression during Xoo infection, some of which encoded bacterial pathogen resistance-related protein. Induction of AP2 domain containing transcription factors along with up-regulation of their putative target genes during Xoo infection may inhibit pathogen spread in the bbr1. This observation supports the hypothesis that AP2 domain containing transcription factors is involved in the regulation of differentially expressed genes in bbr1.