University of Georgia researchers report on heritable DNA methylation marks in the model plant Arabidopsis thaliana. The team turned to whole-genome bisulfite sequencing to uncover methylated regions and find differentially methylated regions in two mutation-prone A. thaliana lines over multiple generations. The vast majority of methylated regions were passed down from one plant generation to the next, the authors report, making it possible to establish epigenotype maps for teasing apart Arabidopsis genotypes based on DNA methylation marks. "This novel epigenotyping procedure and the resulting data suggest that spontaneous epialleles are sources of allelic variation in crop genomes that are likely stable enough to be used in breeding programs," they write.
Investigators from Shenzhen University and other centers in China, the US, and Taiwan explore small RNA pathways and microRNA families in more than two dozen land plants from the lycophyte or fern lineages. Based on RNA and small RNA sequence data for four lycophyte and 21 fern species, the team catalogued miRNAs, small interfering RNAs, and other regulatory RNAs in the plant species, before putting together a phylogenetic tree to untangle the roots of regulatory gene families during land plant diversification. "Our phylogenetic analyses of miRNAs in bryophytes, lycophytes, ferns, and angiosperms refine the time-of-origin for conserved miRNA families as well as small RNA machinery in land plants," the authors write.
A Chinese Academy of Sciences- and Washington State University-led team takes a look at genetic networks contributing to traits of interest in the soybean crop plant, Glycine max. Using 421 soybean landraces and 388 soybean cultivars — all sequenced and genotyped for the new study or in the past — the researchers carried out a genome-wide association study searching for SNPs associated with dozens of agronomical traits phenotyped in the soybean accessions grown at three sites over two years. Their search led to 245 loci associated with crop traits such as oil or protein content, growth patterns, and seed development, pointing to dozens of traits that appear to be governed by interacting loci or genetic networks.