ABSTRACT
Soil salinity is a major environmental problem owing to its negative impact on agricultural productivity and sustainability. Nanoparticles (NPs) have recently been highlighted for their ability to alleviate salinity stress. The current study aimed to alleviate salt stress by using silicon (Si) and selenium (Se) NPs on the growth and physiological attributes of Physalis alkekengi L. Plants were irrigated with saline water at 50, 100, and 200 mM NaCl, and Si NPs (200 mg L-1) and Se NPs (50 mg L-1) were sprayed on leaves three times in a pot experiment in 2022. Leaf chlorophyll (Chl) content, antioxidant capacity, and fatty acid (FA) profile of fruits were measured to find the effects of NPs and salinity in the plants. Salinity at 50 mM did not significantly differ from the control, but at 100-200 mM, salt stress had a substantial impact on the majority of traits. Compared with non-saline conditions, 200 mM NaCl led to decreases in shoot weight (40%), fruit weight (30%), Chl a (30%), Chl b (39%), anthocyanin (31%), ascorbic acid (16%), total phenolic content (TPC, 11%) but increases in total soluble solids (TSS, 79%), titration acidity (TA, 17%), and TSS/TA (52%) in plants without spraying the NPs. However, Si and Se NPs modulated salinity stress by increasing shoot and fruit weight, Chl content, anthocyanin, and TPC, and with decreasing TSS and TSS/TA. Salinity elevated polyunsaturated fatty acids (PUFAs) and lowered monounsaturated fatty acids (MUFAs). According to multivariate analysis, 50 mM and control were found to be in the same cluster, whereas 100 and 200 mM were shown to be in different clusters. Foliar application of Si and Se NPs at 200 and 50 mg L-1, respectively, can be recommended for mitigating salt stress at 100-200 mM NaCl in P. alkekengi L. Plants. Farmers can use the findings to increase the ability of Si and Se NPs to protect plants against salt.
ABSTRACT
BACKGROUND: There is little information on the effect of nutrient solutions composition on Arabidopsis growth. Therefore, we compared growth performance of Arabidopsis thaliana (Col-0) grown on the most commonly used nutrient solutions in deep water culture: Hoagland and Arnon, Murashige and Skoog, Tocquin, Hermans, and Conn. In addition to these nutrient solution composition experiments, we established Arabidopsis growth response curves for nutrient solution concentration and salt stress (NaCl). RESULTS: Arabidopsis rosette fresh and dry weight showed an approximate linear decline with NaCl dose in deep water culture, i.e. 9% reduction relative to control per unit of electrical conductivity (EC in dS m-1, for scale comprehension 1 dS m-1 equals ~ 10 mM NaCl). The Tocquin, ½Hoagland and Conn nutrient solutions had equal and optimal growth performance. Optimal nutrient solution concentration for Tocquin and Hoagland was 0.8 to 0.9 dS m-1. Close to the EC of ½Hoagland (1.1 dS m-1), which is frequently used in Arabidopsis research. Conn solution showed optimal growth at much higher EC (2 dS m-1) indicating that it is a balanced nutrient solution that matches the needs of Arabidopsis. Full Murashige and Skoog solution (5.9 dS m-1) was lethal and diluted solutions (EC of 1.6 and 1.1 dS m-1) caused stress symptoms and severe growth retardation at later developmental stages. CONCLUSIONS: Arabidopsis thaliana (Col-0) plants grown in deep water culture showed a sixfold growth difference when commonly used nutrient solutions were compared. Murashige and Skoog solution should not be used as nutrient solution in deep water culture. Conn, Tocquin and ½Hoagland are balanced nutrient solutions which result in optimal Arabidopsis growth in hydroponic systems.
