Hydrogen peroxide promotes seed germination, but the molecular mechanisms underlying this process are unclear. This study presents the results of eggplant (Solanum melongena) germination analyses conducted at two different temperatures and follows the effect of hydrogen peroxide treatment on seed germination and the seed proteome. Hydrogen peroxide was found to promote eggplant germination in a way not dissimilar to that of increased temperature stimuli. LC–MS profiling detected 729 protein families, 77 of which responded to a temperature increase or hydrogen peroxide treatment. These differentially abundant proteins were found to be involved in a number of processes, including protein and amino acid metabolism, carbohydrate metabolism, and the glyoxylate cycle. There was a very low overlap between hydrogen peroxide and temperature-responsive proteins, highlighting the differences behind the seemingly similar outcomes. Furthermore, the observed changes from the seed proteome indicate that hydrogen peroxide treatment diminished the seed endogenous hydrogen peroxide pool and that a part of manifested positive hydrogen peroxide effect might be related to altered sensitivity to abscisic acid.

Wild Solanum accessions are a treasured source of resistance against pathogens, including oomycete Phytophthora infestans, causing late blight disease. Here, Solanum pinnatisectum, Solanum tuberosum, and the somatic hybrid between these two lines were analyzed, representing resistant, susceptible, and moderately resistant genotypes, respectively. Proteome and metabolome analyses showed that the infection had the highest impact on leaves of the resistant plant and indicated, among others, an extensive remodeling of the leaf lipidome. The lipidome profiling confirmed an accumulation of glycerolipids, a depletion in the total pool of glycerophospholipids, and showed considerable differences between the lipidome composition of resistant and susceptible genotypes. The analysis of putative resistance markers pinpointed more than 100 molecules that positively correlated with resistance including phenolics and cysteamine, a compound with known antimicrobial activity. Putative resistance protein markers were targeted in an additional 12 genotypes with contrasting resistance to P. infestans. At least 27 proteins showed a negative correlation with the susceptibility including HSP70-2, endochitinase B, WPP domain-containing protein, and cyclase 3. In summary, these findings provide insights into molecular mechanisms of resistance against P. infestans and present novel targets for selective breeding.

Potato (Solanum tuberosum) is a valuable staple crop that provides nutrition for a large part of the human population around the world. However, the domestication process reduced its resistance to pests and pathogens. Phytophthora infestans, the causal agent of late blight disease, is the most destructive pathogen of potato plants. Considerable efforts have been made to develop late blight-resistant potato cultivars, but the success has been limited and present-day potato production requires the extensive use of fungicides. In this review, we summarize known sources of late blight resistance and obstacles in P. infestans control. We outline the problematic aspects of chemical treatment, the possible use of biological control, and available resources of natural resistance in wild Solanum accessions. We focus on prospective putative markers of resistance that are often overlooked in genome-centered studies, including secondary metabolites from alkaloid, phenylpropanoid, and terpenoid classes, lipids, proteins, and peptides. We discuss the suitability of these molecules for marker-assisted selection and the possibility of increasing the speed of conventional breeding of more resilient cultivars.

Malting of barley grains is a procedure known for centuries, however, the technology of malt production is constantly being studied and optimized. The optimizations comprise different conditions of barley steeping, as well as using different additives to improve seed germination. Among the most famous group of seed germination regulators, gibberellins, a broad spectrum of diverse chemical substances also have stimulatory effects on seed germination. This review summarizes what is known about multiple barley seed germination promoting compounds, as well as other chemical/hormonal seed germination regulators described in other plant species. The goal is to provide an impulse for testing new stimulatory substances with potential applications in malting process optimization.