Project description:Landscape characteristics and social behavior can affect the foraging patterns of seed-dependent animals. We examine the movement of acorns from valley oak (Quercus lobata) trees to granaries maintained by acorn woodpeckers (Melanerpes formicivorus) in two California oak savanna-woodlands differing in the distribution of Q. lobata within each site. In 2004, we sampled Q. lobata acorns from 16 granaries at Sedgwick Reserve in Santa Barbara County and 18 granaries at Hastings Reserve in Monterey County. Sedgwick has lower site-wide density of Q. lobata than Hastings as well as different frequencies of other Quercus species common to both sites. We found acorn woodpeckers foraged from fewer Q. lobata seed source trees (K(g) = 4.1 ± 0.5) at Sedgwick than at Hastings (K(g) = 7.6 ± 0.6) and from fewer effective seed sources (N(em)* = 2.00 and 5.78, respectively). The differences between sites are due to a greater number of incidental seed sources used per granary at Hastings than at Sedgwick. We also found very low levels of seed source sharing between adjacent granaries, indicating that territoriality is strong at both sites and that each social group forages on its own subset of trees. We discovered an interesting spatial pattern in the location of granaries. At Sedgwick, acorn woodpeckers situated their granaries within areas of higher-than-average tree density, while at Hastings, they placed them within areas of lower-than-average tree density, with the outcome that granaries at the two sites were located in areas of similar valley oak density. Our results illustrate that landscape characteristics might influence the number of trees visited by acorn woodpeckers and the locations of territories, while woodpecker social behavior, such as territoriality, shapes which trees are visited and whether they are shared with other social groups.
Project description:Climate change over the next century is predicted to cause widespread maladaptation in natural systems. This prediction, as well as many sustainable management and conservation practices, assumes that species are adapted to their current climate. However, this assumption is rarely tested. Using a large-scale common garden experiment combined with genome-wide sequencing, we found that valley oak (Quercus lobata), a foundational tree species in California ecosystems, showed a signature of adaptational lag to temperature, with fastest growth rates occurring at cooler temperatures than populations are currently experiencing. Future warming under realistic emissions scenarios was predicted to lead to further maladaptation to temperature and reduction in growth rates for valley oak. We then identified genotypes predicted to grow relatively fast under warmer temperatures and demonstrated that selecting seed sources based on their genotype has the potential to mitigate predicted negative consequences of future climate warming on growth rates in valley oak. These results illustrate that the belief of local adaptation underlying many management and conservation practices, such as using local seed sources for restoration, may not hold for some species. If contemporary adaptational lag is commonplace, we will need new approaches to help alleviate predicted negative consequences of climate warming on natural systems. We present one such approach, "genome-informed assisted gene flow," which optimally matches individuals to future climates based on genotype-phenotype-environment associations.
Project description:(Iso)flavonoids are one of the largest groups of natural phenolic products conferring great value to the health of plants and humans. Pueraria lobata, a legume, has long been used in Chinese traditional medicine. (Iso)flavonoids mainly present as glycosyl-conjugates and accumulate in P. lobata roots. However, the molecular mechanism underlying the glycosylation processes in (iso)flavonoid biosynthesis are not fully understood. In the current study, three novel UDP-glycosyltransferases (PlUGT4, PlUGT15, and PlUGT57) were identified in P. lobata from RNA-seq data. Biochemical assays of these three recombinant PlUGTs showed all of them were able to glycosylate isoflavones (genistein and daidzein) at the 7-hydroxyl position in vitro. In comparison with the strict substrate specificity for PlUGT15 and PlUGT57, PlUGT4 displayed utilization of a broad range of sugar acceptors. Particularly, PlUGT15 exhibited a much higher catalytic efficiency toward isoflavones (genistein and daidzein) than any other identified 7-O-UGT from P. lobata. Moreover, the transcriptional expression patterns of these PlUGTs correlated with the accumulation of isoflavone glucosides in MeJA-treated P. lobata, suggesting their possible in vivo roles in the glycosylation process.
Project description:The O-methylation is an important tailing process in Pueraria lobata isoflavone metabolism, but the molecular mechanism governing it remains not elucidated. This manuscript describes the mining of key O-methyltransferases (OMTs) involved in the process. Using our previously constructed P. lobata transcriptome, the OMT candidates were searched, extensively analyzed, and their functions were investigated by expression in yeast, Escherichia coli, or Glycine max hairy roots. Here, we report the identification of the key OMT gene responsible for formononetin production in P. lobata (designated as PlOMT9). PlOMT9 primarily functions as an isoflavone-specific 4'-O-methyltransferase, although it shows high sequence identities with isoflavone 7-O-methyltransferases. Moreover, unlike the previously reported OMTs that catalyze the 4'-O-methylation for formononetin biosynthesis at the isoflavanone stage, PlOMT9 performs this modifying step at the isoflavone level, using daidzein rather than 2,7,4'-trihydroxy-isoflavanone as the substrate. Gene expression analyses and metabolite profiling supported its proposed roles in P. lobata. Using the system of transgenic G. max hairy roots, the role of PlOMT9 in the biosynthesis of formononetin was further demonstrated in vivo.