It is firmly established that plants respond to biotic and abiotic stimuli by emitting volatile organic compounds (VOCs). These VOCs provide information on the physiological status of the emitter plant and are available for detection by the whole community. In the context of plant-plant interactions, research has focused mostly on the defence-related responses of receiver plants. However, responses may span hormone signalling and both primary and secondary metabolism, and ultimately affect plant fitness. Here we present a synthesis of plant-plant interactions, focusing on the effects of VOC exposure on receiver plants. An overview of the important chemical cues, the uptake and conversion of VOCs, and the adsorption of VOCs to plant surfaces is presented. This is followed by a review of the substantial VOC-induced changes to receiver plants affecting both primary and secondary metabolism and influencing plant growth and reproduction. Further research should consider whole-plant responses for the effective evaluation of the mechanisms and fitness consequences of exposure of the receiver plant to VOCs.

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Volatile organic compounds are important mediators of mutualistic interactions between plants and their physical and biological surroundings. Volatiles rapidly indicate competition or potential threat before these can take place, and they regulate and coordinate adaptation responses in neighbouring plants, fine-tuning them to match the exact stress encountered. Ecological specificity and context-dependency of plant-plant communication mediated by volatiles represent important factors that determine plant performance in specific environments. In this review, we synthesise the recent progress made in understanding the role of plant volatiles as mediators of plant interactions at the individual and community levels, highlighting the complexity of the plant receiver response to diverse volatile cues and signals and addressing how specific responses shape plant growth and survival. Finally, we outline the knowledge gaps and provide directions for future research. The complex dialogue between the emitter and receiver based on either volatile cues or signals determines the outcome of information exchange, which shapes the communication pattern between individuals at the community level and determines their ecological implications at other trophic levels.

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Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

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While high-throughput sequencing methods are revolutionizing fungal ecology, recovering accurate estimates of species richness and abundance has proven elusive. We sought to design internal transcribed spacer (ITS) primers and an Illumina protocol that would maximize coverage of the kingdom Fungi while minimizing nontarget eukaryotes. We inspected alignments of the 5.8S and large subunit (LSU) ribosomal genes and evaluated potential primers using PrimerProspector. We tested the resulting primers using tiered-abundance mock communities and five previously characterized soil samples. We recovered operational taxonomic units (OTUs) belonging to all 8 members in both mock communities, despite DNA abundances spanning 3 orders of magnitude. The expected and observed read counts were strongly correlated (r = 0.94 to 0.97). However, several taxa were consistently over- or underrepresented, likely due to variation in rRNA gene copy numbers. The Illumina data resulted in clustering of soil samples identical to that obtained with Sanger sequence clone library data using different primers. Furthermore, the two methods produced distance matrices with a Mantel correlation of 0.92. Nonfungal sequences comprised less than 0.5% of the soil data set, with most attributable to vascular plants. Our results suggest that high-throughput methods can produce fairly accurate estimates of fungal abundances in complex communities. Further improvements might be achieved through corrections for rRNA copy number and utilization of standardized mock communities. Importance Fungi play numerous important roles in the environment. Improvements in sequencing methods are providing revolutionary insights into fungal biodiversity, yet accurate estimates of the number of fungal species (i.e., richness) and their relative abundances in an environmental sample (e.g., soil, roots, water, etc.) remain difficult to obtain. We present improved methods for high-throughput Illumina sequencing of the species-diagnostic fungal ribosomal marker gene that improve the accuracy of richness and abundance estimates. The improvements include new PCR primers and library preparation, validation using a known mock community, and bioinformatic parameter tuning.

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Plants emit a plethora of volatile organic compounds, which provide detailed information on the physiological condition of emitters. Volatiles induced by herbivore feeding are among the best studied plant responses to stress and may constitute an informative message to the surrounding community and further function in plant defence processes. However, under natural conditions, plants are potentially exposed to multiple concurrent stresses with complex effects on the volatile emissions. Atmospheric pollutants are an important facet of the abiotic environment and can impinge on a plant's volatile-mediated defences in multiple ways at multiple temporal scales. They can exert changes in volatile emissions through oxidative stress, as is the case with ozone pollution. The pollutants, in particular, ozone, nitrogen oxides and hydroxyl radicals, also react with volatiles in the atmosphere. These reactions result in volatile breakdown products, which may themselves be perceived by community members as informative signals. In this review, we demonstrate the complex interplay among stresses, emitted signals, and modification in signal strength and composition by the atmosphere, collectively determining the responses of the biotic community to elicited signals.

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