Root microbial community profiles can come to the aid of drought sensitive plants grown under desert farming conditions, according to a team from Italy, Tunisia, and Egypt reporting in PLOS One. The researchers used 16S ribosomal RNA sequencing to tease apart the structure of root-associated microbiomes in Capsicum annuum, a drought sensitive pepper plant. Their analyses of samples collected in and around the roots of pepper plants grown under desert farming conditions in Egypt suggest that desert-grown plants can marshal the help of microbes that confer enhanced drought resistance. "[T]he C. annuum rhizosphere under desert farming enriched populations of [plant growth promoting] bacteria capable of enhancing plant photosynthetic activity and biomass synthesis … under drought stress," the University of Milan's Daniele Daffonchio, the study's senior author, and colleagues explain.
In PLOS Genetics, researchers from Gambia and the UK use signs of selection in Plasmodium falciparum to find and characterize antigens produced by the malaria parasite. The investigators generated genome-wide short read sequence data from 65 P. falciparum strains isolated from patients in Gambia in 2008. By comparing these reads to a P. falciparum reference genome, the team tracked down variant patterns suspected to stem from balancing selection related to host immune responses. Signatures of such selection appeared to be more common among genes expressed during a stage of development in which parasites invade host red blood cells, they report, noting that "[v]ariation in expression of polymorphic antigens under balancing selection may be more common than previously thought, requiring further study to assess vaccine candidacy."
A team from Brazil, the UK, and Portugal takes on pathogens from the Leishmania genus in PLOS Neglected Tropical Diseases. The researchers relied primarily on multi-locus sequencing typing at four housekeeping genes, which they found to be useful for distinguishing between the almost 100 Leishmania strains they tested. And based on the taxonomic, phylogenic, and population genetic patterns gleaned from the 96 isolates, investigators argued that MLST could be a suitable typing strategy for the trypanosome parasites, known for causing leishmaniasis in humans. "Overall the results point to the feasibility of an MLST scheme," they write, "and indicate that the four gene fragments analyzed could form part of this typing system."