16S rRNA Gene Diversity of Bacterial Endophytes in Parasitic Cuscuta campestris and Its Helianthus annuus Host.

Here, we report the results of 16S rRNA gene amplicon sequencing of bacterial endophytes from parasitized and unparasitized samples of the common sunflower (Helianthus annuus) and samples of its associated plant parasite field dodder (Cuscuta campestris), collected from one location in Fresno County, California (August 2017).

Draft Genome Sequence of a Multidrug-Resistant Strain of Enterococcus faecalis, PM01, Isolated from the Nest of an American Bushtit, Psaltriparius minimus.

Pathogenic microorganisms associated with avian nests may detrimentally impact parental health and nest success for the nest primary users, potentially neighboring avian or terrestrial species, including humans. Here, we report the genome sequence of Enterococcus faecalis strain PM01, isolated from a failed nest of American bushtits, Psaltriparius minimus.

Effects of ionizing radiation exposure on Arabidopsis thaliana.

The effects of ionizing radiation on Arabidopsis thaliana were investigated using 6 MV x-rays produced by a linear accelerator. Photosynthesis and respiration rates, chlorophyll fluorescence (fv/fm ratio and yield), plant height, total leaf area, stem mass, leaf mass, and above-ground biomass were measured to evaluate both physiological and physical impacts of ionizing radiation. The statistical analysis examined the radiation effects with respect to four different total doses (0.5 Gy, 5 Gy, 50 Gy, and 150 Gy), two different treatment types (single and fractionated), and irradiation at one of three different life stages (15 days, 20 days, and 25 days old). Results indicate that the age at the time of radiation exposure plays an important role in integrating radiation effects, and the irradiated A. thaliana indicated greater divergences in terms of physical growth compared to the internal physiological reactions. The results suggest that flowering plants like A. thaliana are capable of being utilized as a biodosimeter and further studies can be performed on specific areas, such as microscopic analysis of a plant's internal structure in order to assess the effects of ionizing radiation for a practical application.

Supply and demand processes as controls over needle monoterpene synthesis and concentration in Douglas fir [Pseudotsuga menziesii (Mirb.) Franco].

We measured the relative control that resource availability (as a supply-side control) and wounding (as a demand-side control) exert on patterns of monoterpene synthesis and concentration in Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] needles. While supply-side controls should alter monoterpene production due to changes in the availability of substrate (carbohydrates), demand-side controls alter the need for a defensive product. We examined these relationships by measuring constitutive (preformed) and wound-induced rates of monoterpene synthesis and pool sizes in trees grown under ambient and elevated (ambient +200 µmol mol-1) CO2, ambient and elevated (ambient +4°C) temperature, and in trees grown under four levels of nitrogen fertilization (0, 50, 100 and 200 µg g-1 N by weight). Monoterpene pool size decreased at elevated CO2, increased at elevated temperature and did not change in response to nitrogen fertilization. Overall, we did not find that foliar nitrogen, carbon balance, or rate of monoterpene synthesis alone were consistent predictors of monoterpene concentration in current-year Douglas fir needles. In addition, despite a wound-induced decrease in monoterpene pool size, we found no evidence for induction of monoterpene synthesis in response to wounding. The influence of either resource availability or wounding on rates of monoterpene synthesis or accumulation cannot be explained by traditional supply-side or demand-side controls. We conclude that monoterpene synthesis in first-year Douglas fir needles is controlled by fairly conservative genetic mechanisms and is influenced more by past selection than by current resource state.