The use of osmoregulators and antioxidants to mitigate the adverse impacts of salinity stress in diploid and tetraploid potato genotypes (Solanum spp.)

Haitham E M Zaki,Khlode S A Radwan

doi:10.1186/s40538-022-00286-3

Haitham E M Zaki, Khlode S A Radwan

Open Access

https://doi.org/10.1186/s40538-022-00286-3

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Abstract

BackgroundMany arid and semi-arid areas endure from extensive salinization of agricultural land. Nevertheless, it must either develop salinity-tolerant varieties or use agronomic treatments to alleviate the symptoms of stress. Although the cultivated potato, Solanum tuberosum L., is relatively salt sensitive, salinity tolerance was demonstrated in several Solanum relatives. Knowledge of genetic variation for salinity tolerance across diverse species is required for breeding of salinity-tolerant cultivars. Higher osmotic pressures associated with salinity impede plant development and cause plant death; yet, the exogenous application of cellularly recognized molecules to withstand such stress might be a key method.ResultsIn vitro studies were performed to determine how much genetic variability for salinity tolerance exists in S. tuberosum (tbr), a tetraploid species and S. chacoense (chc), a diploid species in which 13 genotypes were evaluated under 100, 200 or 300 mmol L−1 NaCl and the average tested parameters were compared with the control (no stress). A further experiment was conducted to investigate the effect of exogenous application of osmoregulators and antioxidants, namely, glycine betaine (GB), proline (P) and salicylic acid (SA) at 400, 200 and 100 mg L−1, respectively, which applied solely to counteract the harmful effect of stress on potato plants. The results showed that when plants exposed to salinity, root characteristics, plantlet water content % (PWC), chlorophyll and K+ content, and callus formation all substantially reduced; however, Cl− and Na+ levels, as well as catalase and peroxidase activity, were elevated. In general, chc showed more tolerance compared to tbr with genetic diversity within and among species. Under stress, chc clones, ‘A-6’, ‘C-8’ and ‘D-2’ and tbr cultivars, ‘Diamond’ and ‘Russet Burbank’ were more tolerant and yielded the greatest salinity tolerance index. Under stress but with applied GB, SA and P, the adverse consequences of stress were relieved. GB was found to be a good treatment for enhancing all the examined traits.ConclusionThe results indicated that there is a significant genetic variation in salt tolerance between (tbr) cultivars and (chc) clones. GB followed by SA and P could completely or partly reverse the adverse impact of salinity stress on potato plants.Graphical

Highlights

Potato, along with wheat and rice, is one of the world’s most important food crops
Explants were grown on media supplemented with three different concentrations of NaCl (100, 200 or 300 mmol L −1) and the average tested parameters over the combined three levels of stress were compared with the control replications (n = 10) in a split block design
Genotypes were grown in vitro on media supplemented with three different concentrations of NaCl (100, 200 or 300 mmol L −1) and the average tested parameters throughout the combined three levels of stress were compared with the control, whereas in the second experiment, to teste the effect of exogenous application of osmoregulators and antioxidants on alleviating the adverse impact of salinity, glycine betaine (GB), proline (P) and salicylic acid (SA) were solely added to the Murashige and Skoog (MS) growth medium which was supplemented with high stress level of NaCl (300 mmol L−1)

Summary

Introduction

Along with wheat and rice, is one of the world’s most important food crops. Cultivated tetraploid potatoes (Solanum tuberosum L.) originated in the Andes of South America, where they were mostly farmed at elevations ranging from 2000 to 4000 m in an environment characterized by short daylength, high light intensity, cold temperatures, and relatively high humidity [1]. Tetraploid potato cultivars are moderately sensitive to moderately tolerant to salinity, depending on the criteria used for classification [3,4,5]. This sensitivity is related to the growth stage of the plant, being more sensitive to salinity in the early growth periods [6, 7]. Many arid and semi-arid areas endure from extensive salinization of agricultural land It must either develop salinity-tolerant varieties or use agronomic treatments to alleviate the symptoms of stress. Higher osmotic pressures associated with salinity impede plant development and cause plant death; yet, the exogenous application of cellularly recognized molecules to withstand such stress might be a key method

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