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Background: Global climate changes may impact the growth and management of weed species. The aim of this work was to evaluate the impact of recent climate changes on the growth of weeds and herbicide efficacy. The effects of temperature, carbon dioxide (CO 2 ), and herbicide on growth and control of Bromus tectorum L., Hordeum murinum L., and Lactuca serriola L. were studied. Treatments included: control or ambient environment (CO 2 concentration 400-450 ppm; temperature 20/10 °C day/night); elevated temperature (CO 2 concentration 400-450 ppm; temperature 25/15 °C day/night); high CO 2 and elevated temperature (CO 2 concentration 800-900 ppm; temperature 25/15 °C day/night); high CO 2 (CO 2 concentration 800-900 ppm; temperature 20/10 °C day/night). Glyphosate rates (active ingredient) used in the experiment were: 0 g ha -1 (untreated control); 360 g ha -1 ; 720 g ha -1 ; 1080 g ha -1 ; 1440 g ha -1 (recommended rate), and 2880 g ha -1 ., Results: High CO 2 concentration and high CO 2 concentration plus high temperature improved the biomass and growth parameters of weeds in the studies. In general, high temperature had a neutral, negative or slightly positive effect on the growth of weed species. Climatic conditions did not affect the activity of glyphosate; its application provided equal and effective weed control under both CO 2 and temperature levels and their combinations., Conclusion: The positive effect of high CO 2 concentration on the growth of weeds does not impact the activity of glyphosate. © 2017 Society of Chemical Industry., (© 2017 Society of Chemical Industry.)

Plants form ubiquitous associations with diverse microbes. These interactions range from parasitism to mutualism, depending partly on resource supplies that are being altered by global change. While many studies have considered the separate effects of pathogens and mutualists on their hosts, few studies have investigated interactions among microbial mutualists and pathogens in the context of global change. Using two wild grass species as model hosts, we grew individual plants under ambient or elevated CO(2), and ambient or increased soil phosphorus (P) supply. Additionally, individuals were grown with or without arbuscular mycorrhizal inoculum, and after 2 wk, plants were inoculated or mock-inoculated with a phloem-restricted virus. Under elevated CO(2), mycorrhizal association increased the titer of virus infections, and virus infection reciprocally increased the colonization of roots by mycorrhizal fungi. Additionally, virus infection decreased plant allocation to root biomass, increased leaf P, and modulated effects of CO(2) and P addition on mycorrhizal root colonization. These results indicate that plant mutualists and pathogens can alter each other's success, and predict that these interactions will respond to increased resource availability and elevated CO(2). Together, our findings highlight the importance of interactions among multiple microorganisms for plant performance under global change., (© 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.)

We have used a frequency-selective rotational-echo double-resonance (REDOR) solid-state NMR experiment to measure the concentrations of glycine-glycine pairs in proteins (and protein precursors) of intact leaves of plants exposed to both high- and low-CO(2) atomospheres. The results are interpreted in terms of differences in cell-wall biosynthesis between plant species. We illustrate this variability by comparing the assimilation of label in cheatgrass and soybean leaves labeled using (15)N-fertilizer and (13)CO(2) atmospheres. Cheatgrass and soybean are both C(3) plants but differ in their response to a high-CO(2) environment. Based on REDOR results, we determined that cheatgrass (a plant that seems likely to flourish in future low-water, high-CO(2) environments) routes 2% of the assimilated carbon label that remains in the leaf after 1 h in a 600-ppm (13)CO(2) atmosphere to glycine-rich protein (or its precursors), a structural component of cell walls cross-linked to lignins. In contrast, soybean under the same conditions routes none of its assimilated carbon to glycine-rich protein.