Biology subjects

Leisner, C.

Publications and source records attributed to Leisner, C..

5 recordsLinked to original sources

bioRxiv2025

Development and validation of ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method to quantify monotropein in blueberries

Blueberries (Vaccinium species) are an economically important fruit crop rich in bioactive compounds like polyphenols and flavonoids. Interestingly, some blueberry cultivars also produce monotropein, which has bioactive properties, including anti-inflammatory and neuroprotective effects. However, methods to quantify monotropein in blueberries have not been optimized. To address this gap, an optimized analytical method for monotropein extraction and quantification using liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed. Different extraction strategies were compared, including variations in temperature, time, and ultrasonication treatments. Optimal extraction was achieved by heating samples to 60{degrees}C for 15 minutes in methanol. The method had high percent recovery (89-110% intraday; 91-108% interday) and good repeatability (1.17-2.15% relative standard deviation (RSD) intraday; 4.68-7.16% RSD interday). This protocol was then applied to 28 blueberry cultivars, 14 of which had not been previously analyzed for monotropein. Monotropein ranged from 0-1807 ng/mg dry weight. The developed method provides a robust tool that can be applied to future evaluations of monotropein in diverse blueberry cultivars.

biochemistry↗

bioRxiv2025

Impacts of projected elevated temperature on estimated chilling accumulation and bud break of rabbiteye blueberries

Climate change poses a significant threat to perennial fruit crops, including blueberries, by altering temperature-dependent developmental processes such as dormancy and bud break. This study investigates the projected impacts of mid-21st century warming on chilling accumulation and phenological development in rabbiteye blueberry (Vaccinium virgatum) cultivars Krewer and Titan. Using downscaled climate projections from 20 global climate models under the RCP 8.5 scenario, we estimated future temperature trends for a key southeastern U.S. blueberry production region. We quantified changes in chilling hours, chilling portions, and freeze event probabilities between historical (1981-2000) and projected (2041-2070) periods. Results indicate a substantial reduction in chilling accumulation--chilling hours decreased by 66.6% and chilling portions by nearly half--alongside a delayed onset and shortened duration of chilling periods. Despite warming, freezing events are still expected during critical phenological windows, potentially increasing frost damage risk. Growth chamber experiments simulating ambient and elevated temperature regimes revealed significant cultivar-specific shifts in the timing and rate of bud break and bloom stages. Logistic models developed from these data provide predictive tools for assessing phenological responses under future climates. These findings highlight the vulnerability of rabbiteye blueberry to climate-induced dormancy disruption and underscore the need for adaptive management strategies and cultivar selection to sustain productivity in a warming climate.

plant biology↗

bioRxiv2024

Nutrient Challenges in a Changing Atmosphere: Investigating Biomass Growth and Mineral Concentration Changes in Soybean Plants under Elevated CO2

Rising atmospheric CO2 levels, projected to reach [~]650 ppm by 2050, threaten the nutritional value of food crops. This rise is expected to increase biomass yield in C3 plants through enhanced photosynthesis and water-use efficiency. However, elevated CO2 (eCO2) reduces protein, nitrogen, and essential minerals like zinc (Zn) and iron (Fe) in plant leaves and seeds, posing a global nutrition risk. We conducted an experiment using Open Top Chambers to examine the response of three soybean cultivars (Clark, Flyer, and Loda) to ambient ([~]410 ppm) and eCO2 ([~]610 ppm) conditions. These cultivars were selected due to their contrasting responses to eCO2. Measurements of physiological parameters (i.e., biomass, and nutrient concentration) were taken at different growth stages. Our results showed that eCO2 increased carbon assimilation, leading to higher aboveground biomass and seed yield (through increased seed number) while root biomass remained unchanged. eCO2 also reduced stomatal conductance and transpiration. There was a significant decrease in seed nutrient concentration at maturity, particularly iron (Fe), phosphorous (P), potassium (K), and magnesium (Mg), in plants grown in eCO2. These findings suggest that increased yield, reduced transpiration, and unchanged root biomass are key drivers of nutrient dilution in seeds under eCO2.

plant biology↗

bioRxiv2024

Physiological and Molecular Responses of Projected Future Temperatures on Potato Tuberization

Potato (Solanum tuberosum L.) is one of the most important food crops globally and is especially vulnerable to heat stress. Significant knowledge gaps remain however, in our understanding of the developmental mechanisms associated with tuber responses to heat stress. This study uses whole-plant physiology, transcriptomics, and hormone profiling to gain insights into the mechanisms associated with heat stress impacts on potato tuber development. When plants were grown in projected future temperature conditions, levels of abscisic acid (ABA) were significantly decreased in leaf and tuber tissues while rates of leaf carbon assimilation and stomatal conductance were not significantly affected. While plants grown in elevated temperature conditions initiated more tubers on average per plant, there was a significant decrease (66%) in mature tubers at final harvest. We hypothesize that reduced tuber yields at elevated temperatures are not due to reductions in tuber initiation, but due to impaired tuber filling. Transcriptomic analysis found significant changes in transcript expression for genes related to response to ABA, heat and auxin biosynthetic process. The known tuberization repressor genes SELF PRUNING 5G (StSP5G) and CONSTANS-LIKE1 (StCOL1) were found to be differentially expressed in tubers grown in elevated temperatures. IDENTITY OF TUBER 1 (StIT1) and TIMING OF CAB EXPRESSION 1 (StTOC1) are other known tuberization genes that displayed distinct expression patterns in elevated versus ambient temperatures but were not differentially expressed. This work highlights potential gene targets and key developmental stages associated with tuberization to development more heat tolerant potatoes.

plant biology↗

bioRxiv2022

Biotic and abiotic stress distinctly drive the phyllosphere microbial community structure

While the physiological and transcriptional response of the host to biotic and abiotic stresses have been intensely studied, little is known about the resilience of associated microbiomes and their contribution towards tolerance to these stresses. We evaluated the impact of one such abiotic stress, elevated tropospheric ozone (O3), under open-top chamber field conditions on host susceptibility and phyllosphere microbiome associated with pepper cultivars resistant and susceptible to Xanthomonas. Pathogen challenge resulted in distinct microbial community structures in both cultivars under an ambient environment. Elevated O3 alone affected microbial community structure associated with resistant cultivar but not the susceptible cultivar, indicating the role of host genotypic background in response to abiotic stress. Elevated O3 did not influence overall host susceptibility but did increase disease severity on the resistant cultivar, indicating a possible compromise in the resistance. Interestingly, combined stress resulted in a shift in microbial composition and structure like that observed with pathogen challenge alone. It indicates the possible prioritization of community response towards the most significant stress and pathogen being most influential regardless of the cultivar. Despite community composition differences, overall functional redundancy was observed in the phyllosphere community. To gain insights into community-level interactions, network topology assessment indicated a stable network with enhanced taxon connectedness upon pathogen challenge. However, an observation of destabilized random network with a shift in hub taxa in the presence of combined stress warrants future studies on the consequences of such unstable microbial communities on host response to pathogens in the face of climate change.

ecology↗