Secondary compost products improved tomato production via regulating primary/secondary metabolism and hormone signal interaction

The secondary compost products (SCP), originated from secondary composting process of the agriculture organic waste fermentation CO2 enrichment devices, can promote tomato plants growth, yield and fruit quality, while reducing the emission of greenhouse gas and organic wastes to the environment, which contributing to the building of carbon neutral and peak. However, the molecular mechanisms and metabolic pathways by which tomato plants responses to SCP treated soil are unknown. In this case, leaf metabolome and transcriptome were compared in the tomato plants grown under SCP, chemical fertilizer (CF) and organic fertilizer (OF). Results showed that SCP application improved primary metabolism especially TCA cycle, carbohydrate metabolism and amino acid metabolism, and also enhanced secondary metabolism especially phenylpropanoid metabolism in tomato leaves when compared with that of CF. Meanwhile, SCP induced significantly down-regulation in ethylene-related genes, while up-regulation in jasmonic acid and gibberellin related genes, which together with the increase of Jasmonate ZIM-domain protein and decrease of DELLA protein endow good balance between growth and environment adaptation ability of plants under SCP treatment. Our findings provide an insight into the molecular and metabolomic response to SCP treated tomato plants for the first time, contributing to the construction of climate-smart agriculture.