Drought stress affects bioactive compounds in potatoes (Solanum tuberosum L.) relevant to non-communicable diseases

Abstract

Background: Potatoes react very sensitive to drought during growth, and appropriate plant stress responses may affect metabolites associated with the health quality of tubers.Objective: The aim of this study is to determine the effects of drought stress (DS) on soluble sugars, starch, crude protein, minerals, free amino acids (AAs) and fatty acids (FAs).Design: The experiment was carried out on three potato genotypes during two years with four replications. The plants were grown in pots, in a glasshouse with optimal water supply and under drought stress conditions. After harvest, the tubers of these two variants were analyzed for bioactive compounds relevant to non-communicable diseases (NCDs). Results: Apart from genotypic differences in most parameters, the results revealed that the DS caused a decline in glucose and fructose (P < 0.05, all) in both years, whereas sucrose was increased, especially in the second year with severe stress (P < 0.01). Starch was significantly reduced by moderate stress in the first year (P < 0.01), but less affected in the second year. Crude proteins and total amounts of free amino acids (AAs) were clearly enhanced by the stress in both years (P < 0.05, all), similarly as the minerals magnesium (Mg), potassium (K) and phosphorus (P) (P < 0.05, all), whereas calcium (Ca) declined (P < 0.05). The portion of α-linolenic acid (ALA) on total lipids was elevated in the stress variants (P < 0.01), while oleic acid (OLA), its precursor decreased significantly (P < 0.05), but only in the first year. In the second year, ALA was in general higher and not further induced by the stress. Also OLA was less affected in that year, similarly as all other FAs in both years. Interestingly, Myo-inositol (MI) and lipid acyl hydrolases (LAH) associated with modulation in cell membrane lipids raised by the drought stress in each year (P < 0.01, all). In the second year, MI and LAH data of the drought stressed tubers correlated significantly (r = 0.90, P < 0.01) indicating their joined action within plant stress responses.Conclusions: The biochemical changes induced by DS are not alarming with regard to NCDs. Decline in glucose, fructose and starch, and increase in crude proteins, free AAs, ALA, MI and minerals like Mg, K and P, on the other side, is profitable for the health benefits of tubers. However, a better quality is associated with a decrease in tuber yield.Keywords: potato, drought stress, bioactive compounds, chronic diseases

Effect of Plant Biostimulants on Macronutrient Content in Early Crop Potato Tubers

“…The macronutrient contents in tubers of very early potato cultivars tested were similar, except Mg. Tubers of 'Miłek' contained lower Mg than 'Denar' and 'Lord'. Wegener et al [38] reported that K, P, and Mg content in potato tubers increased, while Ca content reduced as a result of drought stress, which was not confirmed in the present study. According to Mazurczyk and Lis [39], weather conditions during potato growth have no effect on macronutrient content in tubers.…”

Effect of drought and waterlogging on saccharides and amino acids content in potato tubers

“…In the present study, the conditions of used stress were characterised by high intensity of severity according to average relative water content in leaves RWC 73.23% for DS and 87.10% for WLS. In both milder or severer conditions of two years, Wegener et al (2017) observed an increase of sucrose and a decrease of glucose and fructose in three potato genotypes.…”

Linking abiotic stress, plant metabolites, biostimulants and functional food

“…Considering drought stress influence on fruit quality, water had a significant effect on carbon partitioning at fruit maturation, whereas the intensity of metabolic changes increases as fruit ripens during the final slow growth period, when glucose and fructose continue to accumulate, and the concentration of soluble sugars reaches a maximum (Luo, Kang, & Chen, 2020). Drought stress impact on potato tuber yield and quality was assessed by Wegener, Jurgens, and Jansen (2017), who reported an increase in free amino acids, α‐linolenic acid, myo‐inositol and minerals like magnesium, potassium and phosphorus in tubers of drought‐stressed plants. The authors highlighted proline, an osmoprotectant in plants, as amino acid which plays significant roles in human nutrition, through protein metabolism, particularly in the synthesis of arginine, polyamines and glutamate, in addition to wound healing processes and immune responses.…”