Juvenile Chinook salmon (Oncorhynchus tshawytscha) exhibit an array of life history tactics in Oregon's Willamette River Basin, yet we do not know to what extent it is driven by phenotypic plasticity or whether it is predetermined and how conditions in the early rearing environment may affect phenotype expression. We have...
Hydraulic conductance of leaves (K[subscript leaf]) typically decreases with increasing water stress and recent studies have proposed different mechanisms responsible for decreasing K[subscript leaf]. We measured K[subscript leaf] concurrently with ultrasonic acoustic emissions (UAEs) in dehydrating leaves of several species to determine whether declining K[subscript leaf] was associated with xylem...
Dams have contributed to the decline of migratory fishes by blocking access to historical habitat. The active transport (trap and haul) of migratory fish species above existing dams can sometimes support population recovery when the use of fish ladders or dam removal is infeasible. However, little is known about the...
In RNA-directed silencing pathways, ternary complexes result from small RNA-guided ARGONAUTE (AGO) associating with target transcripts. Target transcripts are often silenced through direct cleavage (slicing), destabilization through slicer-independent turnover mechanisms, and translational repression. Here, wild-type and active-site defective forms of several Arabidopsis thaliana AGO proteins involved in posttranscriptional silencing were...
Flowering is the primary trait affected by ambient
temperature changes. Plant microRNAs
(miRNAs) are small non-coding RNAs playing an
important regulatory role in plant development. In
this study, to elucidate the mechanism of
flowering-time regulation by small RNAs, we
identified six ambient temperature-responsive
miRNAs (miR156, miR163, miR169, miR172, miR398
and...
Eukaryotic small RNA (~20-30 nucleotides) are diverse regulatory molecules that repress gene expression at the transcriptional and post-transcriptional levels, defend hosts against invading viruses and defend genomes against selfish DNA elements. Small RNA populations are studied by high-throughput sequencing of the total small RNA fraction isolated from cells, however, the...
RNA interference pathways can involve amplification of secondary siRNAs by RNA-dependent RNA polymerases. In plants, RDR6-dependent secondary siRNAs, including transacting siRNAs (tasiRNAs), arise from transcripts targeted by some microRNAs (miRNAs). In the case of TAS3 tasiRNA formation, ARGONAUTE7 (AGO7)-miR390 complexes interact with primary transcripts at two sites, resulting in recruitment...
The Pentatricopeptide Repeat (PPR) gene family produces RNA-binding proteins that target organellar transcripts. The PPR family is expanded in land plants, with nearly 450 genes identified in Arabidopsis thaliana. In plants with a Cytoplasmic Male Sterility (CMS) phenotype, members of the PPR family can act as a RESTORER OF FERTILITY...