Arsenic is a serious soil pollutant with toxic effects on biological systems. Elevated soil concentrations may negatively affect crop production and food safety. The impact of arsenic on plants depends on many factors, including nitrogen availability. Nitrogen (N) as an essential mineral affects overall energetics of plants, while its non-optimal doses have been shown to also impact plant performance and yield, as well as tolerance to environmental constraints. The combined effects of these two factors, however, have been rarely studied. Here we investigated the impact of sublethal doses of As³⁺ (5 mM) on wheat plants grown in hydropony, applying a set of 8 different N concentrations spanning from starvation (0 mM N in the media) through optimum (7.5 mM N) to excessive amounts (up to 35 mM N). The results showed that the content of photosynthetic pigments varies depending on N concentration and As³⁺ presence. The different energetic status of plants also affected the final As uptake. Establishing nutrition conditions might be important for limiting metal(loid) uptake from soil in contaminated areas.

We conducted analyses on 253 protein sequences (Pfam00257) derived from 25 woody plant species, including trees, shrubs, and vines. Our goal was to gain insights into their architectural types, biochemical characteristics, and potential involvement in mitigating abiotic stresses, such as drought, cold, or salinity. The investigated protein sequences (253) comprised 221 angiosperms (85 trees/shrubs and 36 vines) and 32 gymnosperms. Our sequence analyses revealed the presence of seven architectural types: K_n, K_nS, SK_n, Y_nK_n, Y_nSK_n, FSK_n, and F_nK_n. The FSK_n type predominated in tree and shrub dehydrins of both gymnosperms and angiosperms, while the YnSKn type was more prevalent in vine dehydrins. The Y_nSK_n and Y_nK_n types were absent in gymnosperms. Gymnosperm dehydrins exhibited a shift towards more negative GRAVY scores and Fold Indexes. Additionally, they demonstrated a higher Lys content and lower His content. By analyzing promoter sequences in the angiosperm species, including trees, shrubs, and vines, we found that these dehydrins are induced by the ABA-dependent and light-responsive pathways. The presence of stress- and hormone-related cis-elements suggests a protective effect against dehydration, cold, or salinity. These findings could serve as a foundation for future studies on woody dehydrins, especially in the context of biotechnological applications.

Winter survival of crops is influenced by multiple environmental stress factors, including low temperature, excessive soil moisture, and pathogen pressure. With climate change, the role of flooding during cold acclimation has become increasingly important. This study examined the effect of cold flooding on frost tolerance of two winter rye (Secale cereale L.) lines differing in resistance to snow mould. Plants were subjected to cold acclimation for three weeks at 4 °C, followed by ten days of flooding at the same cold temperature. Cold flooding improved frost tolerance only in the snow mould-resistant line (343), which maintained the presence of a 50 kDa β-1,3-glucanase isoform and exhibited a flooding-induced decrease in cytosolic sucrose synthase (SuS) activity in leaves, while maintaining higher SuS activity in roots. In contrast, the less resistant line (620) lacked the 50 kDa isoform in roots and showed substantially lower SuS activity than line 343; however, leaf SuS activity increased during prolonged flooding to levels comparable with those of line 343. The 35 kDa isoform was no longer detectable in the leaves of either line after one or ten days of flooding, whereas in the roots of both lines, its accumulation was maintained after one day but was abolished after ten days of flooding. Additionally, line 620 exhibited prolonged flooding-induced upregulation of glu-8 and TLP3 genes, which, in the absence of protein accumulation, suggests post-transcriptional or translational constraints associated with prolonged stress. These findings demonstrate that higher frost tolerance under cold flooding involves the accumulation of specific pathogenesis-related (PR) proteins, maintaining a high reduced and oxidised glutathione ratio and metabolic adjustment of sucrose synthesis. Furthermore, cold acclimation alone did not differentiate frost tolerance between rye genotypes differing in snow mould resistance, whereas flooding under low-temperature conditions enhanced freezing tolerance only in the resistant line, indicating that flooding may function as a positive signal involved in frost tolerance induction.