An international team reports the first genome sequence for a non-seed vascular plant, the lycophyte Selaginella moellendorffii. In its comparative evolutionary analysis, the team found that "Selaginella differs in post-transcriptional gene regulation, including small RNA regulation of repetitive elements, an absence of the tasiRNA pathway and extensive RNA editing of organellar genes," the team writes in a paper published online in advance in Science this week.
In another Science advance online publication, a team led by researchers at Wageningen University in the Netherlands reports its use of PhyloChip-based metagenomics and culture-dependent functional analyses to decipher the rhizosphere microbiome of key disease-suppressive bacteria. Overall, the Wadeningen-led team's study suggests "that upon attack by a fungal root pathogen, plants can exploit microbial consortia from soil for protection against infections."
Using shotgun sequencing on uncultured marine picobiliphytes, investigators at the Bigelow Laboratory for Ocean Sciences and their colleagues identified "distinct interactions of individual cells," and found "no evidence of plastid DNA nor of nuclear-encoded plastid-targeted proteins, which suggests that these picobiliphytes are heterotrophs," they report in this week's Science. In addition, the researchers also report single-cell sequencing data that is "dominated by sequences from a widespread single-stranded DNA virus," they report.
Researchers in Switzerland and Spain this week show that the "transient activation of the Hog MAPK pathway regulates bimodal gene expression." More specifically, the team shows that the activation of Hog1 increases along with stimuli, such as osmotic stress, and that "a slow, stochastic transition from a repressed to an activated transcriptional state in conjunction with transient Hog1 activation generates this behavior." Overall, the team says that its study suggests "a molecular mechanism by which a cell can impose a transcriptional threshold in response to a linear signaling behavior."