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

Abstract

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.

Antioxidant responses to drought and salinity in Lavandula angustifolia Mill.

“…The results of the present study confirm previous data (Szekely-Varga et al, 2020), clearly indicating that the responses to water deficit and salt stress of the two selected varieties of L. angustifolia, 'Codreanca' (LAC) and 'Sevtopolis' (LAS), were very similar. Lavender growth was significantly reduced with increased salt concentration and under water deficit conditions, which influenced the plant biomass; however, all plants survived the strong stress conditions applied, indicating that lavender is relatively tolerant to both, drought and salinity.…”

“…Growth inhibition is a very general response to stress, as plants under stressful conditions reallocate their growth and primary metabolism resources to the activation of defence mechanisms (Munns and Tester, 2008;Hendawy and Khalid, 2005). The study mentioned above (Szekely-Varga et al, 2020), focused on the effects of the stress treatments on growth, ion transport and osmolyte accumulation in plants of the two lavender varieties. We reported some variations in the mean values of several growth parameters; however, the differences were too small to allow considering any of the two varieties as more stress-tolerant than the other.…”

“…'Sevtopolis' (LAS) from Bulgaria. Their growth responses, together with an analysis of the uptake and transport of ions to the leaves and the accumulation of osmolytes have been published previously (Szekely-Varga et al, 2020). The aim of the present study was to investigate the effects of the applied drought and salinity treatments on the generation of oxidative stress and the activation of antioxidant mechanisms in the two cultivars.…”

Physiology Response and Resistance Evaluation of Twenty Coconut Germplasm Resources under Low Temperature Stress

“…As an antioxidant and a free radical scavenger, Pro can scavenge active oxygen, protect protein, and cell membrane structure [54]. Pro, like soluble protein, has a high solubility that allows it to lower the freezing point of plant cells, inhibit water loss, and maintain cell osmotic balance, which together enable plants to improve the stress resistance [55,56]. The decrease in Pro content at 5 • C might be influenced by the fact that the temperature was too low to cause serious damage to the cell membrane, and the regulation and protection mechanism of proline was destroyed, resulting in the loss of intracellular material and the decrease of Pro content [57].Therefore, increasing Pro content at low temperature was conducive to improving the tolerance of plants, and Pro content could be defined as an important indicator to evaluate plant resistance.…”

Morphological Responses of Viola Accessions to Nutrient Solution Application and Electrical Conductivity

“…Salt stress can cause premature aging of the leaves and chloroplast and chlorophyll content reduction [ 23 ], which eventually leads to plant death [ 24 , 25 ]. High salinity stress makes it difficult for the plants to uptake nutrients and also water, due to a lower water potential in the soil, which leads to water shortage in plants [ 26 , 27 ]. The main ions responsible for salinity stress are Na + , K + , and Ca 2+ .…”