Untargeted metabolites and chemometric approach to elucidate the response of growth and yield attributes on different concentrations of an amino acid based biostimulant in two lettuce cultivars

• Published in: Scientia horticulturae 2022-12, Vol.306, p.111478, Article 111478
• Main Authors: Mpai, Semakaleng, Mokganya, Lerato M., Raphoko, Lerato, Masoko, Peter, Ndhlala, Ashwell R.
• Format: Article
• Language: English
• Subjects: amino acids; antioxidants; carotenoids; chemical composition; Chemometric analysis; chemometrics; cultivars; flavonoids; foliar application; Growth and yield components; Lettuce; metabolites; metabolome; Phytostim® biostimulant; Untargeted metabolites profiling
• ISSN: 0304-4238; 1879-1018
• DOI: 10.1016/j.scienta.2022.111478

•Application of Phytostim® biostimulant at 3% dose improved growth and yield components in lettuce cv ‘Lara’ and ‘Elisa’.•Application of Phytostim® biostimulant at 6% dose retarded growth and yield components in lettuce cv ‘Lara’ and ‘Elisa’.•There was major heterogeneity on untargeted metabolites profile in control (untreated) samples of both cv ‘Lara’ and ‘Elisa’ using the LC-MS data and chemometrics techniques.•Targeted metabolites including total phenols, flavonoids, carotenoids and chlorophyll elucidated the antioxidant activity in studied treatments.•Obtained results is practically beneficial on sustainable strategies to improve productivity. The study aims to underpin biochemical mechanisms induced by the application of different concentrations of an amino-acid based Phytostim® biostimulant on growth and yield attributes. Different concentrations of Phytostim® biostimulant: 0 (untreated), 1, 3, and 6% were foliar applied on lettuce cultivars (‘Lara’ and ‘Elisa’). After 45 days of transplanting, analysis growth and yield attributes, biochemical analysis and LC-MS untargeted metabolites profile were performed. Application of 3% dose improved both growth and yield parameters in both cultivars in comparison to the 6% dose which inhibited growth. Similar trend was observed for biochemical and antioxidant analysis (phenolic, flavonoids, carotenoids, chloroplyll a and b and scavenging activity). The PCA and OPLS-DA score-plot clustered the metabolome profile of biostimulant treated vs untreated samples with major heterogeneity distinction observed in the untreated samples. Obtained results validate the use of biostimulants in agriculture while giving information on the effects of the treatments towards changes in the chemical composition within the studied cultivars.