Transcriptomic and metabolomic analysis provides insights into the fruit quality and yield improvement in tomato under soilless substrate-based cultivation

Authors: GUO, JINGHUA - Hebei Academy Of Agriculture & Forestry; DONG, LINGDI - Hebei Academy Of Agriculture & Forestry; Kandel, Shyam; JIAO, YONGGANG - Hebei Academy Of Agriculture & Forestry; SHI, LINQI - Hebei Academy Of Agriculture & Forestry; YANG, YUBAO - Hebei Academy Of Agriculture & Forestry; SHI, AINONG - University Of Arkansas; Mou, Beiquan

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/4/2022
Publication Date: 4/12/2022
Citation: Guo, J., Dong, L., Kandel, S.L., Jiao, Y., Shi, L., Yang, Y., Shi, A., Mou, B. 2022. Transcriptomic and metabolomic analysis provides insights into the fruit quality and yield improvement in tomato under soilless substrate-based cultivation. Agronomy. 12(4). Article 923. https://doi.org/10.3390/agronomy12040923.
DOI: https://doi.org/10.3390/agronomy12040923

Interpretive Summary: The effects of soilless substrate versus soil-based cultivation on quality and yield of tomato (Solanum lycopersicum) were studied using the cultivar Zhonghua Lvbao as the experimental material. The results showed that the plant height, stem diameter and chlorophyll content of tomato under substrate cultivation increased by 37.3%, 19.8% and 15.3%, respectively, compared with soil-based cultivation. Leaf photosynthesis and root longevity of tomato under substrate cultivation increased 21.2% to 84.5%, compared with soil-cultivation. The yield increased 10.1% compared with soil-cultivation. The contents of total soluble sugar, soluble solid, and vitamin C were 35.7%, 19.7%, and 18.2%, respectively higher than those of soil-cultivation, while nitrate and acid contents were 29.4% and 11.8%, respectively lower than those of soil-cultivation. Therefore, substrate-cultivation can increase production and improve tomato quality and taste. In order to find the cause of tomato quality improvement by substrate cultivation, the metabolites and gene activities of ‘Zhonghua Lvbao’ were determined. The results showed that 24 metabolites were increased and 36 were decreased. The activities of 321 genes were increased, and 155 were decreased. The genes and metabolites related to quality were mainly concentrated in vitamin B6, vitamin C, and glycerolipid metabolic pathways, resulting the increased contents of vitamins B6 and C. Therefore, substrate cultivation can elevate vitamin and soluble sugar contents and the activities of fruit flavor related genes, which lays a theoretical foundation for exploring the mechanism of substrate cultivation to improve the quality of tomato.

Technical Abstract: The effects of soilless substrate-based versus soil-based cultivation on overall quality and yield in tomato (Solanum lycopersicum) were studied using the tomato cv. Zhonghua Lvbao. The results showed that the plant height, stem diameter and chlorophyll content of tomato under substrate-based cultivation were increased by 37.3%, 19.8% and 15.3%, respectively, compared with soil-based cultivation system. Leaf photosynthetic rate, transpiration rate, stomatal conductance, and root vitality of tomato under substrate-based cultivation increased 29.0%, 21.2%, 43.9% and 84.5%, respectively, compared with soil-cultivation. The yield reached 7,177.5 kg/667 m2, and the relative yield increased 10.1% compared with soil-cultivation. The contents of total soluble sugar (40.8 mg/g), soluble solid (5.2%), and vitamin C (28.3 mg/100g) were 35.7%, 19.7%, and 18.2%, respectively higher than those of soil-cultivation, while nitrate content (203.0 mg/kg) and titratable acid (0.45%) were 29.4% and 11.8%, respectively lower than those of soil-treatment. Therefore, substrate-based-cultivation can increase production and improve tomato quality and taste. We examined the expressed genes and metabolites in order to explore the molecular mechanism of plant growth and overall fruit quality improvement in substrate-based cultivation. A total of 476 differentially expressed genes were identified by transcriptome profile, of which 321 and 155 were significantly up-and down regulated, respectively. The results of metabolomics analysis showed that 441 metabolites were detected, where 24 and 36 metabolites were up-and down regulated, respectively. By combining analyses of transcription and metabolic groups, genes and metabolites related to the fruit quality were mainly concentrated in vitamin B6 metabolic pathway, ascorbate and aldarate acid metabolic pathways, and glycerophospholipid metabolic pathway. Therefore, substrate-based cultivation can elevate vitamin and soluble sugar contents and the expression of fruit flavor related genes, which lays an initial background for exploring the mechanism of substrate-based cultivation to improve the quality of tomato in the future.