The Regulation Of Brassionosteroids Pretreatment And CO₂ Enrichment On The Phytotoxicity Of Pesticides In Sub-Optimum Condition

Pesticides generate large benefits in protecting crops from pests and in enhancing crop yields in agriculture. However, the improper usage of pesticides can exert phytotoxicity on exposed crops when high incidence of pests and diseases occurs in intensive facilities. Furthermore, because of the limitation of agriculture facility in our country, the thermophilic crops are mostly cultivated in unheated greenhouse during the cool season, and the suboptimal condition with chilling temperature and low light is critical for agricultural productivity. Therefore, the study on the impacts of pesticides on crops under sub-optimum condition and the environmentally friendly and affordable solution for phototoxicity are of great significance.In our study, the cucumber and tomato were cultivated under suboptimal condition controlled by artificial climate chamber, and then were pretreated with 24-epibrassinolide (EBR) before the exposure of cypermethrin, carbendazim and chlorpyrifos, or were enriched the concentration of CO2. The transcriptional changes of genes involved in various physiological processes such as photosynthesis, antioxidant, detoxification, defense and signal transduction were detected as the endpoints to evaluate the regulation of EBR pretreatment and CO2 enrichment on the phytotoxicity of pesticides. The results showed that the all three pesticides displayed phytotoxic on cucumber and tomato, and both EBR pretreatment and CO2 enrichment could release the phytotoxicity to a certain extent, which being consistent with our expectations.Our research preliminary explored the role of plant hormone and the concentration of CO2 on the regulation of phytotoxicity, and provided helpful information for the appropriate application of pesticides in greenhouse production.