Frass from yellow mealworm (Tenebrio molitor) as plant fertilizer and defense priming agent

Producción CientíficaWorld population growth requires the development of a sustainable agriculture that allows feeding all the inhabitants of the planet, while reducing the use of agrochemicals. Currently, the insect farming industry for food and feed production is developing exponentially throughout the world; also producing insect frass with a potential utilization within agriculture and greenhouse industry. In the case of the yellow mealworm (Tenebrio molitor), few studies have been developed so far on the use of frass as a fertilizer, and there are none on its ability to activate plant defenses. By applying 2% sterilized mealworm frass to tomato we found a significant increase in its growth, demonstrating that the microbiota might not play a key role in its fertilizing capacity. In addition, the application of frass to sunflowers under different situations of nutritional deficit allowed us to determine what specific nutrients this fertilizer may be providing to the plant, finding a possible deficiency in the supply of N, but with sufficient amounts of P, K, Ca, and S. With respect to the induction of defenses, mealworm insect frass did not induce local root defenses in a root callose deposition assay in Arabidopsis thaliana under our experimental conditions. However, it activated systemic defenses in Arabidopsis thaliana by inducing defense genes in the absence of pathogen, further enhanced by infection with the necrotrophic fungus Botrytis cinerea. Therefore, mealworm frass could be a good fertilizer resource and plant defense inducer to support development of sustainable agriculture.Norwegian Research Council (grant RCN 250953

Extreme low temperature tolerance in woody plants

Woody plants in boreal to arctic environments and high mountains survive prolonged exposure to temperatures below -40°C and minimum temperatures below -60°C, and laboratory tests show that many of these species can also survive immersion in liquid nitrogen at -196°C. Studies of biochemical changes that occur during acclimation, including recent proteomic and metabolomic studies, have identified changes in carbohydrate and compatible solute concentrations, membrane lipid composition, and proteins, notably dehydrins, that may have important roles in survival at extreme low temperature (ELT). Consideration of the biophysical mechanisms of membrane stress and strain lead to the following hypotheses for cellular and molecular mechanisms of survival at ELT: (1) Changes in lipid composition stabilize membranes at temperatures above the lipid phase transition temperature (-20 to -30°C), preventing phase changes that result in irreversible injury. (2) High concentrations of oligosaccharides promote vitrification or high viscosity in the cytoplasm in freeze-dehydrated cells, which would prevent deleterious interactions between membranes. (3) Dehydrins bind membranes and further promote vitrification or act stearically to prevent membrane–membrane interactions.© 2015 Strimbeck, Schaberg, Fossdal, Schröder and Kjellsen. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms

Herbivores reduce seedling recruitment in alpine plant communities

publishedVersio

Herbivores reduce seedling recruitment in alpine plant communities

publishedVersio

Metabolite changes in conifer buds and needles during forced bud break in Norway spruce (Picea abies) and European silver fir (Abies alba)

Environmental changes such as early spring and warm spells induce bud burst and photosynthetic processes in cold-acclimated coniferous trees and consequently, cellular metabolism in overwintering needles and buds. The purpose of the study was to examine metabolism in conifers under forced deacclimation (artificially induced spring) by exposing shoots of Picea abies (boreal species) and Abies alba (temperate species) to a greenhouse environment (22°C, 16/8 h D/N cycle) over a nine week period. Each week, we scored bud opening and collected samples for GC/MS–based metabolite profiling. We detected a total of 169 assigned metabolites and 80 identified metabolites, comprising compounds such as mono- and disaccharides, Krebs cycle acids, amino acids, polyols, phenolics and phosphorylated structures. Untargeted multivariate statistical analysis based on PCA and cluster analysis segregated samples by species, tissue type, and stage of tissue deacclimations. Similar patterns of metabolic regulation in both species were observed in buds (amino acids, Krebs cycle acids) and needles (hexoses, pentoses, and Krebs cycle acids). Based on correlation of bud opening score with compound levels, distinct metabolites could be associated with bud and shoot development, including amino acids, sugars and acids with known osmolyte function, and secondary metabolites. This study has shed light on how elevated temperature affects metabolism in buds and needles of conifer species during the deacclimation phase, and contributes to the discussion about how phenological characters in conifers may respond to future global warming

Experimental Assessment of the Environmental Impact of Ethanolamine

The environmental impact of ethanolamine, a common amine for carbon dioxide capture, was experimentally investigated in laboratory scale microcosms. By exposing the plant-soil systems to varying amounts of ethanolamine, we assessed the effects a potential leakage or spill to the surroundings of an industrial site including vegetation. The results of this study show that small amounts of ethanolamine have no significant impact of the health of the plants in the scope of three weeks after treatment. Plant health was affected negatively by larger amounts of ethanolamine, but the plants treated with larger ethanolamine concentrations also seemed to be healthier, lusher and greener after three weeks of observation. Unfortunately, this positive observation, indicating an actual fertilizing effect by ethanolamine on the plants could not be verified. In the TCCS-11 presentation we will show the results of this experimental study, their statistical interpretation, as well the implications the results hav

Functional group contributions to carbon fluxes in arctic-alpine ecosystems

Ongoing responses to climate change in arctic-alpine ecosystems, including the increasing dominance of deciduous shrubs, involve major shifts in plant functional group composition. Because rates of photosynthesis and respiration and their responses to temperature may vary among plant functional groups, a better understanding of their contributions to carbon fluxes will help improve predictions of how ecosystem changes will affect carbon source-sink relations in globally important tundra regions. We used a sequential harvest method to estimate growing season functional group contributions to net ecosystem exchange (NEE), ecosystem respiration (ER), and gross photosynthesis (GP) in alpine heath-, meadow-, and Salix-dominated shrub communities. We also partitioned ER into aboveground and belowground components in all three communities. Belowground efflux was the dominant component of ER in the heath and meadow communities (63 percent and 88 percent of ER, respectively) but contributed only approximately 40 percent of ER in the shrub community. The dominant functional group in each community contributed most to aboveground exchanges. Estimates for cryptogams were uncertain, but indicated a minor role for bryophytes and lichens in overall exchange. The results of our novel method of partitioning gas-exchange measurements suggest strong differences in the relative proportions of soil versus aboveground respiration and in the contributions of different functional groups in the net carbon exchange of three important arctic-alpine community types, with implications for changes in carbon dynamics as these systems respond to environmental change

Data from: Blossom colour change after pollination provides carbon for developing seeds

1. We tested the hypothesis that greening of the floral (involucral) bracts of Dalechampia scandens blossoms after pollination (when bracts are white) increases carbon assimilation and provides photosynthate to developing seeds. 2. We investigated the importance of the involucral bracts for the process of seed development in two ways. First, we removed or shaded bracts of hand-pollinated blossoms to prevent their photosynthesis and tested the effects of these manipulations on seed development. Secondly, we measured the photosynthetic rate of blossoms with white vs. green bracts and compared these rates with those of leaves. 3. After four weeks of development, seeds from blossoms with bracts removed or shaded were lighter than those produced by unmanipulated blossoms. Furthermore, although the area-based photosynthetic rate of green bracts was much lower than that of leaves, it was much greater than that of white bracts. Estimates of the daily carbon budget based on these measurements indicate that photosynthesis in green bracts is sufficient to meet the respiratory demand of the whole blossom, but not so in white bracts. 4. Our results support the hypothesis that colour change in D. scandens bracts allows carbon assimilation that contributes to the carbon demand of nearby developing seeds

Functional group contributions to carbon fluxes in arctic-alpine ecosystems

Ongoing responses to climate change in arctic-alpine ecosystems, including the increasing dominance of deciduous shrubs, involve major shifts in plant functional group composition. Because rates of photosynthesis and respiration and their responses to temperature may vary among plant functional groups, a better understanding of their contributions to carbon fluxes will help improve predictions of how ecosystem changes will affect carbon source-sink relations in globally important tundra regions. We used a sequential harvest method to estimate growing season functional group contributions to net ecosystem exchange (NEE), ecosystem respiration (ER), and gross photosynthesis (GP) in alpine heath-, meadow-, and Salix-dominated shrub communities. We also partitioned ER into aboveground and belowground components in all three communities. Belowground efflux was the dominant component of ER in the heath and meadow communities (63 percent and 88 percent of ER, respectively) but contributed only approximately 40 percent of ER in the shrub community. The dominant functional group in each community contributed most to aboveground exchanges. Estimates for cryptogams were uncertain, but indicated a minor role for bryophytes and lichens in overall exchange. The results of our novel method of partitioning gas-exchange measurements suggest strong differences in the relative proportions of soil versus aboveground respiration and in the contributions of different functional groups in the net carbon exchange of three important arctic-alpine community types, with implications for changes in carbon dynamics as these systems respond to environmental change

Drivers of C cycling in three arctic-alpine plant communities

Recent vegetation changes in arctic-alpine tundra ecosystems may affect several ecosystem processes that regulate microbe and soil functions. Such changes can alter ecosystem carbon (C) cycling with positive feedback to the atmosphere if plant C uptake is less than the amount of soil C released. Here, we examine how differences in plant functional traits, microbial activity, and soil processes within and across Salix-dominated shrub, dwarf shrub-dominated heath, and herb- and cryptogam-dominated meadow communities influence C cycling. We develop a hypothesized framework based on a priori model selection of variation in daytime growing season gross ecosystem photosynthesis (GEP) and above-and belowground respiration. The fluxes were standardized to light and temperature. Gross ecosystem photosynthesis was primarily related to soil moisture and secondarily to plant functional traits and aboveground biomass, and belowground respiration was dependent on the community weighted mean of specific leaf area (SLA(CWM)). Similarly, microbial activity was linked with SLA(CWM) and was highest in meadows, and carbon-degrading microbial activity decreased with vegetation woodiness. These results suggest that shrub expansion may influence summer C cycling differently depending on plant community, as belowground respiration might increase in the heath and decrease in the meadow communities.Department of Biology, NTNU; I.K. Lykkes fond; Nansenfondet; Norwegian Research CouncilResearch Council of Norway [23060/E10]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]