@article{SchmidtkeFindeissSharmaetal.2011, author = {Schmidtke, Cornelius and Findeiß, Sven and Sharma, Cynthia M. and Kuhfuss, Juliane and Hoffmann, Steve and Vogel, J{\"o}rg and Stadler, Peter F. and Bonas, Ulla}, title = {Genome-wide transcriptome analysis of the plant pathogen Xanthomonas identifies sRNAs with putative virulence functions}, series = {Nucleic Acids Research}, volume = {40}, journal = {Nucleic Acids Research}, number = {5}, doi = {10.1093/nar/gkr904}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131781}, pages = {2020 -- 2031}, year = {2011}, abstract = {The Gram-negative plant-pathogenic bacterium Xanthomonas campestris pv. vesicatoria (Xcv) is an important model to elucidate the mechanisms involved in the interaction with the host. To gain insight into the transcriptome of the Xcv strain 85-10, we took a differential RNA sequencing (dRNA-seq) approach. Using a novel method to automatically generate comprehensive transcription start site (TSS) maps we report 1421 putative TSSs in the Xcv genome. Genes in Xcv exhibit a poorly conserved -10 promoter element and no consensus Shine-Dalgarno sequence. Moreover, 14\% of all mRNAs are leaderless and 13\% of them have unusually long 5'-UTRs. Northern blot analyses confirmed 16 intergenic small RNAs and seven cis-encoded antisense RNAs in Xcv. Expression of eight intergenic transcripts was controlled by HrpG and HrpX, key regulators of the Xcv type III secretion system. More detailed characterization identified sX12 as a small RNA that controls virulence of Xcv by affecting the interaction of the pathogen and its host plants. The transcriptional landscape of Xcv is unexpectedly complex, featuring abundant antisense transcripts, alternative TSSs and clade-specific small RNAs.}, language = {en} } @article{WilmsOverloeperNowrousianetal.2012, author = {Wilms, Ina and Overl{\"o}per, Aaron and Nowrousian, Minou and Sharma, Cynthia M. and Narberhaus, Franz}, title = {Deep sequencing uncovers numerous small RNAs on all four replicons of the plant pathogen Agrobacterium tumefaciens}, series = {RNA Biology}, volume = {9}, journal = {RNA Biology}, number = {446-457}, doi = {10.4161/rna.17212}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127101}, pages = {4}, year = {2012}, abstract = {Agrobacterium species are capable of interkingdom gene transfer between bacteria and plants. The genome of Agrobacterium tumefaciens consists of a circular and a linear chromosome, the At-plasmid and the Ti-plasmid, which harbors bacterial virulence genes required for tumor formation in plants. Little is known about promoter sequences and the small RNA (sRNA) repertoire of this and other α-proteobacteria. We used a differential RNA sequencing (dRNA-seq) approach to map transcriptional start sites of 388 annotated genes and operons. In addition, a total number of 228 sRNAs was revealed from all four Agrobacterium replicons. Twenty-two of these were confirmed by independent RNA gel blot analysis and several sRNAs were differentially expressed in response to growth media, growth phase, temperature or pH. One sRNA from the Ti-plasmid was massively induced under virulence conditions. The presence of 76 cis-antisense sRNAs, two of them on the reverse strand of virulence genes, suggests considerable antisense transcription in Agrobacterium. The information gained from this study provides a valuable reservoir for an in-depth understanding of sRNA-mediated regulation of the complex physiology and infection process of Agrobacterium.}, language = {en} }