Effect of extreme temperature changes on phenolic, flavonoid contents and antioxidant activity of tomato seedlings ( Solanum lycopersicum L.)

• Published in: PeerJ (San Francisco, CA) CA), 2021-05, Vol.9, p.e11193-e11193, Article e11193
• Main Authors: Alhaithloul, Haifa A S, Galal, Fatma H, Seufi, AlaaEddeen M
• Format: Article
• Language: English
• Subjects: Abiotic factors; Agricultural production; Agricultural Science; Antioxidants; Benzoic acid; Catechin; Chlorogenic acid; Climate change; Climatic changes; Cold; Cold shock; Cultivars; Ecology; Ecosystem components; Flavonoid content; Flavonoids; Global temperature changes; Heat; Heat shock; High-performance liquid chromatography; Hydroquinone; Isoflavones; Nutritive value; Organic acids; Oxidative stress; Phenolic compounds; Phenolic content; Plant Science; Polyamines; Quercetin; Rutin; Secondary metabolites; Seedlings; Seeds; Solanum lycopersicum; Temperature effects; Thermal sterss; Tomatoes; Vanillic acid
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.11193

Climatic changes are the most important abiotic factor affecting plant growth, crop quality and nutritional value. Plants exposed to thermal stress respond by accumulation of secondary metabolites/molecules (SMs). Tomato ( ) is a cosmopolitan crop, eaten by most of the world's people because it is highly nutritious plant. It is cultivated in more than 16 thousand hectares in Saudi Arabia and thus is influenced by extreme climatic changes. In the current study, the phytochemical effect of thermal stress was investigated in seedlings of . Such information will be very helpful in developing more tolerant tomato cultivars in a climate change scenario. Seedlings of were subjected to heat shock; HS1 and HS2 (45 and 50 °C) and cold shock; CS (4 °C) in comparison to control; Con (25 °C). Phenolic compounds, flavonoids, total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity were estimated under the four temperature treatments. Using 23 standards (17 phenolic and six flavonoids), HPLC resulted in the estimation of 16, 20, 15 and 18 compounds for Con, CS, HS1 and HS2, respectively. Differences in the amounts of total phenolics, and total flavonoids were strongly correlated to thermal stress. CS plants exhibited the highest number of signals and the highest absolute quantities of total phenolics, flavonoids and sum of both. The major peaks of phenolics were (Chlorogenic acid, Resvertol), (Vanillic acid, Benzoic acid, Quinol), (Vanillic acid, Benzoic acid) and (Vanillic acid, Benzoic acid) for Con, CS, HS1 and HS2, respectively. The major peaks of flavonoids were (Quercetin, Myricetin), (Quercetin, Rutin), (Quercetin, Rutin, Catechin) and (Quercetin) for Con, CS, HS1 and HS2, respectively. CS plants contain the highest amounts of Benzoic acid (8010.37 mg/kg FW) and Quercetin (2319.48 mg/kg FW). The highest TPC (131 mg GAE/100 g FW) and TFC (61 mg QE/100 g FW) were determined in the case of CS plants. In terms of IC s, the CS plants showed the highest antioxidant activities (lowest values) in both of DPPH (467.73 µM TE/100 g FW) and ABTS (8.97 µM TE/100 g FW) assays. Our findings supported that the complexity and quantity of phenolics and flavonoids in tomato's extract are strongly related to thermal stress. Additionally, the CS plants demonstrated more desirable phytochemical profile over the other treatments. CS plants exhibited higher number, absolute amounts of SMs, higher TPC and TFC than those of Con, HS1 and HS2 plants. Additionally,