Identification of Salt and Drought Biochemical Stress Markers in Several Silene vulgaris Populations

Abstract

This study attempted to determine short-term responses to drought and salt stress in different Silene vulgaris genotypes and to identify potential abiotic stress biochemical indicators in this species. Four populations from contrasting habitats were subjected to drought and three levels of salinity under controlled greenhouse conditions. The determination of several growth parameters after the stress treatments allowed for ranking the tolerance to stress of the four analyzed populations on the basis of their relative degree of stress-induced growth inhibition. This was then correlated with changes in the leaf levels of monovalent ions (Na+, Cl−, and K+), photosynthetic pigments (chlorophylls a and b, carotenoids), osmolytes (total soluble sugars, proline), and non-enzymatic antioxidants (total phenolic compounds and flavonoids). Despite the observed differences, all four populations appeared to be relatively tolerant to both stress conditions, which in general did not cause a significant degradation of photosynthetic pigments and did not generate oxidative stress in the plants. Drought and salinity tolerance in S. vulgaris was mostly dependent on the use of Na+ and K+ for osmotic adjustment under stress, a mechanism that appeared to be constitutive, and not stress-induced, since relatively high concentrations of these cations (without reaching toxic levels) were also present in the leaves of control plants. The inhibition of additional transportation of toxic ions to the leaves, in response to increasing external salinity, seemed to be a relevant mechanism of tolerance, specifically to salt stress, whereas accumulation of soluble sugars under drought conditions may have contributed to tolerance to drought.

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

“…However, in stems of plants treated with 300 mM NaCl and in leaves at all external salinities, K + contents were similar to the controls, indicating the activation of K + transport to the leaves, increasing the K + /Na + ratio and partly compensating the adverse effects of high Na + concentrations. The same mechanism has been described for other species [64][65][66], and most likely contributes to the (relative) salt tolerance of the lavender varieties. Supporting this notion, recent publications can be cited highlighting the importance of K + homeostasis and the maintenance of a relatively high K + /Na + ratio in leaves of L. stoechas [67], or the fact that foliar K + application ameliorates the responses to salt stress in L. angustifolia [51].…”

The Use of Proline in Screening for Tolerance to Drought and Salinity in Common Bean (Phaseolus vulgaris L.) Genotypes

“…When comparing the stress tolerance of related taxa, for example, different cultivars of a particular crop, measurements of growth parameters are often complemented with the determination of several biochemical stress markers, associated with increased (or lower) tolerance; they include compatible solutes or osmolytes [44][45][46][47]. Proline (Pro) is a common osmolyte in plants, which accumulates in response to different types of abiotic stress, including drought and salinity, in a variety of plant species [28,[48][49][50].…”

The CaChiVI2 Gene of Capsicum annuum L. Confers Resistance Against Heat Stress and Infection of Phytophthora capsici

“…Malondialdehyde (MDA) is an important product of membrane lipid peroxidation (LPO), which is considered as a reliable biochemical oxidative stress marker (Del Rio et al, 1996;Koźmińska et al, 2019). Based on our findings, it can be determined that the CaChiVI2-silenced plants exhibited an increase in MDA level, though the CaChiVI2-overexpressed Arabidopsis plants showed a decrease in MDA level ( Figures 6G, 9F, 10E).…”