Seed plants are sessile organisms that have developed a plethora of strategies for sensing, avoiding, and responding to stress. Several proteins, including the glycine-rich protein (GRP) superfamily, are involved in cellular stress responses and signaling. GRPs are characterized by high glycine content and the presence of conserved segments including glycine-containing structural motifs composed of repetitive amino acid residues. The general structure of this superfamily facilitates division of GRPs into five main subclasses. Although the participation of GRPs in plant stress response has been indicated in numerous model and non-model plant species, relatively little is known about the key physiological processes and molecular mechanisms in which those proteins are engaged. Class I, II, and IV members are known to be involved in hormone signaling, stress acclimation, and floral development, and are crucial for regulation of plant cells growth. GRPs of class IV [RNA-binding proteins (RBPs)] are involved in alternative splicing or regulation of transcription and stomatal movement, seed, pollen, and stamen development; their accumulation is regulated by the circadian clock. Owing to the fact that the overexpression of GRPs can confer tolerance to stress (e.g., some are involved in cold acclimation and may improve growth at low temperatures), these proteins could play a promising role in agriculture through plant genetic engineering. Consequently, isolation, cloning, characterization, and functional validation of novel GRPs expressed in response to the diverse stress conditions are expected to be growing areas of research in the coming years. According to our knowledge, this is the first comprehensive review on participation of plant GRPs in the response to diverse stress stimuli.
Abiotic stress has a significant impact on plant growth and development. It causes changes in the subcellular organelles, which, due to their stress sensitivity, can be affected. Cellular components involved in the abiotic stress response include dehydrins, widely distributed proteins forming a class II of late embryogenesis abundant protein family with characteristic properties including the presence of evolutionarily conserved sequence motifs (including lysine-rich K-segment, N-terminal Y-segment, and often phosphorylated S motif) and high hydrophilicity and disordered structure in the unbound state. Selected dehydrins and few poorly characterized dehydrin-like proteins participate in cellular stress acclimation and are also shown to interact with organelles. Through their functioning in stabilizing biological membranes and binding reactive oxygen species, dehydrins and dehydrin-like proteins contribute to the protection of fragile organellar structures under adverse conditions. Our review characterizes the participation of plant dehydrins and dehydrin-like proteins (including some organellar proteins) in plant acclimation to diverse abiotic stress conditions and summarizes recent updates on their structure (the identification of dehydrin less conserved motifs), classification (new proposed subclasses), tissue- and developmentally specific accumulation, and key cellular activities (including organellar protection under stress acclimation). Recent findings on the subcellular localization (with emphasis on the mitochondria and plastids) and prospective applications of dehydrins and dehydrin-like proteins in functional studies to alleviate the harmful stress consequences by means of plant genetic engineering and a genome editing strategy are also discussed.
Plant transcriptomes are complex entities shaped spatially and temporally by a multitude of stressors. The aim of this review was to summarize the most relevant transcriptomic responses to selected abiotic (UV radiation, chemical compounds, drought, suboptimal temperature) and biotic (bacteria, fungi, viruses, viroids) stress conditions in a variety of plant species, including model species, crops, and medicinal plants. Selected basic and applicative studies employing RNA-seq from various sequencing platforms and single-cell RNA-seq were involved. The transcriptomic responsiveness of various plant species and the diversity of affected gene families were discussed. Under stress acclimation, plant transcriptomes respond particularly dynamically. Stress response involved both distinct, but also similar gene families, depending on the species, tissue, and the quality and dosage of the stressor. We also noted the over-representation of transcriptomic data for some plant organs. Studies on plant transcriptomes allow for a better understanding of response strategies to environmental conditions. Functional analyses reveal the multitude of stress-affected genes as well as acclimatory mechanisms and suggest metabolome diversity, particularly among medicinal species. Extensive characterization of transcriptomic responses to stress would result in the development of new cultivars that would cope with stress more efficiently. These actions would include modern methodological tools, including advanced genetic engineering, as well as gene editing, especially for the expression of selected stress proteins in planta and for metabolic modifications that allow more efficient synthesis of secondary metabolites.
Ninety-one potato genotypes (cultivars and breeding lines) selected as resistant or susceptible to pathotype Ro1 of Globodera rostochiensis were screened for the presence of two PCR markers, 0.14 and 0.76 kb in length. Both PCR markers were linked with the H1 gene, located at the distal end of the long arm of chromosome V, and were present in 88 to 100% of the resistant cultivars and breeding lines. The 0.76 kb PCR marker was detected in all resistant genotypes and in approximately 86% of susceptible breeding lines as well as in all susceptible cultivars. The 0.14 kb marker was detected in 88% of resistant breeding lines and in 94% of resistant cultivars. Most of the susceptible genotypes tested (91% of cultivars, but only 50% of breeding lines) did not show the presence of the 0.14 kb marker. We conclude that the 0.14 kb H1 marker is likely to be useful for the proper selection of potato genotypes resistant to the Ro1 pathotype of G. rostochiensis.