Castasterone attenuates insecticide induced phytotoxicity in mustard

Area of Science:

• Plant Science
• Environmental Toxicology
• Biochemistry

Background:

• Imidacloprid (IMI) is a widely used insecticide causing phytotoxicity in crops.
• Brassinosteroids, like castasterone (CS), are plant hormones with potential protective roles.
• Brassica juncea is a vital oilseed crop susceptible to pesticide stress.

Purpose of the Study:

• To investigate the role of castasterone (CS) in mitigating imidacloprid (IMI) induced phytotoxicity in Brassica juncea.
• To elucidate the physiological and molecular mechanisms underlying CS-mediated protection.
• To assess CS's effect on pigment content, oxidative stress, and pesticide residue levels.

Main Methods:

• Seed treatment with CS was applied to Brassica juncea seedlings exposed to IMI stress.
• Physiological parameters including pigment content and reactive oxygen species (ROS) levels were measured.
• Enzyme activities, organic acid biosynthesis, and gene expression related to stress response and detoxification were analyzed.
• Multivariate statistical techniques like multiple linear regression were employed for data analysis.

Main Results:

• CS seed treatment significantly recovered seedling growth under IMI toxicity.
• CS enhanced chlorophylls, carotenoids, anthocyanins, and xanthophylls, while reducing ROS levels.
• CS activated the antioxidative defense system and stimulated the biosynthesis of Krebs cycle organic acids and phenolics.
• CS modulated gene expression of key enzymes involved in pigment metabolism, carbon fixation, ROS generation, antioxidant defense, and pesticide detoxification, leading to reduced IMI residues.

Conclusions:

• Castasterone effectively alleviates imidacloprid-induced phytotoxicity in Brassica juncea.
• CS acts by enhancing plant growth, improving photosynthetic pigment content, bolstering antioxidant capacity, and promoting pesticide detoxification pathways.
• CS demonstrates potential as a protective agent against insecticide stress in agricultural applications.