Arabidopsis relative Thellungiella salsuginea is an extremophile model for abiotic stress tolerance. In this week's PNAS Early Edition, researchers from the Chinese Academy of Sciences, BGI, and elsewhere present a draft sequence of the T. salsuginea genome, which they "assembled based on [approximately] 134-fold coverage to seven chromosomes with a coding capacity of at least 28,457 genes." Overall, the authors say that "this genome provides resources and evidence about the nature of defense mechanisms constituting the genetic basis underlying plant abiotic stress tolerance."
Elsewhere in the Early Edition, investigators at the University of California, Los Angeles, and their colleagues show that SNPs occur at a rate of about once every 253 basepairs between inbred parents of the Nipponbare and indica (93-11) varieties of rice, "and that these are faithfully transmitted into the hybrids." Further, the UCLA-led team identifies rice "genes with both allele-specific expression patterns that were strongly inherited as well as those differentially expressed between hybrids and the corresponding parental chromosome." Finally, the researchers say much of the so-called misinheritance of expression levels in rice is likely caused by epimutations and trans effects.
University of Washington School of Medicine's Peter Greenberg and his colleagues show in a paper published online in advance in PNAS this week that in the quorum-sensing bacterium Rhodopseudomonas palustris, the antisense rpaR transcript is inhibited by asrpaR and that such inhibition "results in suppression of RpaR-dependent rpaI expression and, thus, pC-HSL production."