Antioxidant responses to drought and salinity in Lavandula angustifolia Mill.

[EN] Drought and salinity are amongst the most damaging environmental stressors that can affect a plant's life cycle, from germination to senescence. In the present study were analysed the responses to salinity and drought in greenhouse-controlled conditions of two varieties of Lavandula angustifolia. Three-month-old lavender seedlings were subjected to water deficit and salt stress (100, 200 and 300 mM NaCl) during a 30-day period. Complementing a previous analysis focused on stress tolerance mechanisms based on the regulation of ion transport and the synthesis of osmolytes, we have now evaluated the effects of the water deficit and salt treatments on the generation of secondary oxidative stress, by measuring malondialdehyde levels, and the activation of antioxidant systems, both non-enzymatic and enzymatic, determining total phenolic compounds and flavonoids contents and calculating superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase specific activities, respectively, in extracts of control and stressed plants. The results obtained confirm that both lavender varieties react in the same way to the applied stress treatments, activating the same antioxidant responses. However, some differences were observed when comparing the specific mechanisms triggered by each type of stress. Thus, the oxidative stress induced under drought conditions was counteracted by accumulation of phenolic compounds and flavonoids, without apparent involvement of antioxidant enzymes. Salt stress, on the other hand, in addition to an increase in flavonoid levels also induced superoxide dismutase and catalase activities. These antioxidant responses are likely to contribute to the relatively high tolerance (as compared to most crops) of lavender to drought and salinity.Z.S.-V. was the recipient of a pre-doctoral Erasmus Mundus scholarship at the Polytechnic University of Valencia, financed by the European Commission.Szekely-Varga, Z.; González-Orenga, S.; Cantor, M.; Boscaiu, M.; Vicente, O. (2020). Antioxidant responses to drought and salinity in Lavandula angustifolia Mill. Notulae Botanicae Horti Agrobotanici Cluj-Napoca. 48(4):1980-1992. https://doi.org/10.15835/48412150S1980199248

Antioxidant responses to drought and salinity in Lavandula angustifolia Mill.

Drought and salinity are amongst the most damaging environmental stressors that can affect a plant's life cycle, from germination to senescence. In the present study were analysed the responses to salinity and drought in greenhouse-controlled conditions of two varieties of Lavandula angustifolia. Three-month-old lavender seedlings were subjected to water deficit and salt stress (100, 200 and 300 mM NaCl) during a 30-day period. Complementing a previous analysis focused on stress tolerance mechanisms based on the regulation of ion transport and the synthesis of osmolytes, we have now evaluated the effects of the water deficit and salt treatments on the generation of secondary oxidative stress, by measuring malondialdehyde levels, and the activation of antioxidant systems, both non-enzymatic and enzymatic, determining total phenolic compounds and flavonoids contents and calculating superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase specific activities, respectively, in extracts of control and stressed plants.  The results obtained confirm that both lavender varieties react in the same way to the applied stress treatments, activating the same antioxidant responses. However, some differences were observed when comparing the specific mechanisms triggered by each type of stress. Thus, the oxidative stress induced under drought conditions was counteracted by accumulation of phenolic compounds and flavonoids, without apparent involvement of antioxidant enzymes. Salt stress, on the other hand, in addition to an increase in flavonoid levels also induced superoxide dismutase and catalase activities. These antioxidant responses are likely to contribute to the relatively high tolerance (as compared to most crops) of lavender to drought and salinity

Effects of Drought and Salinity on Two Commercial Varieties of Lavandula angustifolia Mill

[EN] Global warming is not only affecting arid and semi-arid regions but also becoming a threat to agriculture in Central and Eastern European countries. The present study analyzes the responses to drought and salinity of two varieties of Lavandula angustifolia cultivated in Romania. Lavender seedlings were subjected to one month of salt stress (100, 200, and 300 mM NaCl) and water deficit (complete withholding of irrigation) treatments. To assess the effects of stress on the plants, several growth parameters and biochemical stress markers (photosynthetic pigments, mono and divalent ions, and different osmolytes) were determined in control and stressed plants after the treatments. Both stress conditions significantly inhibited the growth of the two varieties, but all plants survived the treatments, indicating a relative stress tolerance of the two varieties. The most relevant mechanisms of salt tolerance are based on the maintenance of foliar K+ levels and the accumulation of Ca2+ and proline as a functional osmolyte in parallel with increasing external salinities. Under water stress, significant increases of Na+ and K+ concentrations were detected in roots, indicating a possible role of these cations in osmotic adjustment, limiting root dehydration. No significant differences were found when comparing the stress tolerance and stress responses of the two selected lavender varieties.This research was partially funded by the University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, granted to Z.S.-V, and by internal funds of Universitat Politecnica de Valencia. The publication was supported by funds from the National Research Development Projects to finance excellence (PFE)-37/2018-2020 granted by the Romanian Ministry of Research and Innovation.Szekely-Varga, Z.; González-Orenga, S.; Cantor, M.; Jucan, D.; Boscaiu, M.; Vicente, O. (2020). Effects of Drought and Salinity on Two Commercial Varieties of Lavandula angustifolia Mill. Plants. 9(5):1-20. https://doi.org/10.3390/plants9050637S1209

[2,6-Bis(dimethyl­amino­meth­yl)phen­yl]selenium bromide monohydrate

In the title hydrated molecular salt, C12H19N2Se+·Br−·H2O, the two independent bromide anions lie on a twofold rotation axis. Strong intra­molecular N→Se inter­actions [2.185 (3) and 2.181 (3) Å] are established by both N atoms of the organic group in the cation, in trans positions to each other, with an N—Se—N angle of 161.6 (1)°, resulting in a T-shaped (C,N,N′)Se core. In the crystal, dimeric associations are formed by Br⋯Se [3.662 (2) Å] and Br⋯H inter­actions [2.56 (6) and 2.63 (7) Å] involving two bromide anions, two cations and two water mol­ecules

A NOVEL PHENYLALANINE AMMONIA-LYASE FROM KANGIELLA KOREENSIS

This study describes cloning of the gene encoding a novel phenylalanine ammonia-lyase from Kangiella koreensis (KkPAL) into pET19b expression vector. Optimization of protein expression and purification conditions yielded 15 mg pure soluble protein from one liter of E.coli culture. Enzymatic activity measurements of the ammonia elimination reaction from different natural aromatic amino acids proved the protein to be a phenylalanine ammonia-lyase. The isolated protein showed remarkably high, 81.7 °C melting temperature, making it especially suitable for biocatalytic applications

Digenean trematodes in Hungarian freshwater aquacultures

Occurrence of metacercariae of potentially zoonotic trematodes (Platyhelminthes: Digenea) in the musculature of common carp (Cyprinus carpio L. 1758) was monitored in four Hungarian aquacultures. Four geographically distinct fish farms (located in the Northwestern, Southwestern, Northeastern and Southeastern parts of Hungary) were selected for the investigation. From each farm, a total of 258 one-summer-old fingerlings were sampled and examined in the years 2016 and 2017. In addition, in 2017, we examined 60 market size specimens (30 two-summers and 30 three-summers) sampled from the most infected aquaculture in the Northeastern part of Hungary. The fish were euthanized and decapitated whereafter their musculature (fillets) was digested in a pepsin solution to isolate metacercariae from the tissue whereafter morphological and molecular analyses (PCR and sequencing of ITS region) were performed. Opisthorchiid metacercariae were not recovered but in one of the farms numerous metacercariae were detected in the musculature of carp. They were identified as cyathocotylid trematodes based on their morphological characteristics and by sequencing the ITS region. The infection levels proved to be remarkably different among the four fish farms. Carps from the Northeastern farm were infected by large numbers of cyathocotylid metacercariae, while 8 Posthodiplostomum cuticola metacercariae were detected in the Northwestern aquaculture. In the other two farms (Southwestern and Southeastern) no infection was recorded. The infected farm is located close to a protected natural wetland habitat populated by a rich fauna of aquatic birds (potential final hosts) and snails (first intermediate host) which may create a higher risk of infection in the neighbouring fish farms