Plant-virus interactions are frequently influenced by elevated temperature, which often increases susceptibility to a virus, a scenario described for potato cultivar Chicago infected with potato virus Y (PVY). In contrast, other potato cultivars such as Gala may have similar resistances to PVY at both normal (22 °C) and high (28 °C) temperatures. To elucidate the mechanisms of temperature-independent antivirus resistance in potato, we analysed responses of Gala plants to PVY at different temperatures using proteomic, transcriptional and metabolic approaches. Here we show that in Gala, PVY infection generally upregulates the accumulation of major enzymes associated with the methionine cycle (MTC) independently of temperature, but that temperature (22 °C or 28 °C) may finely regulate what classes accumulate. The different sets of MTC-related enzymes that are up-regulated at 22 °C or 28 °C likely account for the significantly increased accumulation of S-adenosyl methionine (SAM), a key component of MTC which acts as a universal methyl donor in methylation reactions. In contrast to this, we found that in cultivar Chicago, SAM levels were significantly reduced which correlated with the enhanced susceptibility to PVY at high temperature. Collectively, these data suggest that MTC and its major transmethylation function determines resistance or susceptibility to PVY.

Drought conditions impact plants at the morphological, physiological, and molecular levels. Plant tolerance to drought conditions is frequently associated with maintaining proteome stability, highlighting the significance of proteomic analysis in understanding the mechanisms underlying plant resilience. Here, we performed proteomic and peptidomic analysis of spring wheat (Triticum aestivum L.) under drought stress conditions. Using isobaric tags for relative and absolute quantitation (iTRAQ), we identified 497 and 157 differentially abundant protein (DAP) groups in leaves and roots, respectively. The upregulated DAP groups in leaves were primarily involved in stress responses, such as oxidative stress and heat response, whereas those in roots were associated with responses to water deprivation and sulfur compound metabolic processes. The analysis of the extracellular root peptidome revealed 2294 native peptides, including members of small secreted peptide (SSP) families. In the peptidomes of stress-induced plants, we identified 16 SSPs as well as peptides derived from proteins involved in cell wall catabolism, intercellular signaling, and stress response. These peptides represent potential candidates as regulators of drought responses. Our results help us to understand adaptation mechanisms and develop new agricultural technologies to increase productivity.

Ethylene, being one of five classical plant phytohormones is involved in regulation of numerous physiological processes. There are contradictory data about the effect of ethylene on the cell growth and division; although it is accepted that in culture flasks, the content of ethylene rises to a few tens of μL/L and production of ethylene is associated with the periods of active growth of the cells in vitro. We revealed a strong correlation (r = 0.96) between ethylene production and specific rate of dry weight accumulation in suspension cell cultures of Ajuga turkestanica, heterotrophic and mixotrophic strains of Arabidopsis thaliana, Beta vulgaris, Euonymus maximoviczianus, Medicago sativa, Panax ginseng, and Triticum timopheevii. In heterotrophic cell culture of A. thaliana, the peaks and general shape of the curves describing dynamics of ethylene production, the number of S-phase cells, and specific rate of increase in cell number coincided in log phase and in the phase of growth deceleration. Pretreatment of subculture inoculum with 100 μL/L ethylene caused doubling of S-phase cell number after 3-h-long culturing in fresh nutrient medium. It was found that exogenous ethylene affects the number of S-phase cells only when the level of endogenously produced ethylene is low.

Small open reading frames (<100 codons) that are located on long noncoding RNAs (lncRNAs) can encode functional microproteins. These microproteins are shown to play important roles in different cellular processes, such as cell proliferation, development and disease response [1], [2], [3], [4], [5], [6]. However, there are only a few known lncRNA-encoded functional microproteins in plants. One such microprotein that was named PSEP3, was identified in the moss Physcomitrium patens by mass-spectrometry analysis. 57-aa PSEP3 contains Low Complexity Region (LCR) enriched with proline. We have previously shown that PSEP3 is translated in protonemata and gametophores of P. patens, and its knockout (KO line) or overexpression (OE line) affects protonemata growth [7]. We performed a quantitative proteomic analysis of the mutant lines with PSEP3 knockout and overexpression. 7-days old protonemata of wild type (WT line) and both mutant lines (KO and OE) were collected and used for iTRAQ-based proteomic experiments. LC-MS/MS data were processed using PEAKS Studio v.8 software with protein identification based on a Phytozome protein database. More analysis of PSEP3 effects on plant growth can be obtained in the paper published in Nucleic Acid Research [8].

Plant growth and development are inextricably connected with rhizosphere organisms. Plants have to balance between strong defenses against pathogens while modulating their immune responses to recruit beneficial organisms such as bacteria and fungi. In recent years, there has been increasing evidence that regulatory peptides are essential in establishing these symbiotic relationships, orchestrating processes that include nutrient acquisition, root architecture modification, and immune modulation. In this review, we provide a comprehensive summary of the peptide families that facilitate beneficial relationships between plants and rhizosphere organisms.

Cysteine-rich peptides belonging to the EPF/EPFL (epidermal patterning factor/epidermal patterning factor-like) family are common in many plants, from mosses to angiosperms. EPF/EPFL play an important role in morphogenesis: they regulate stomatal patterning, the functioning of the shoot apical and lateral meristems, inflorescence architecture, vascular development, growth of leaf margin, as well as the development of flowers and fruits. Recent studies have indicated that EPFL may be involved in plant adaptation to biotic and abiotic stress. This review examines the structure, phylogenetic distribution, mechanisms of signal transduction, and functions of the EPF/EPFL peptide family.