Unraveling the Metabolic Enigma: A High-Resolution LC-MS Approach to Decipher Two Triazine Herbicides Tolerance in...

Area of Science:

• Agricultural Science
• Environmental Chemistry
• Plant Physiology

Background:

• Terbuthylazine (TBA) and metribuzin (MT) are widely used herbicides.
• Understanding their impact on crops like rice and radish is crucial for sustainable agriculture.
• Crop rotation systems necessitate knowledge of herbicide tolerance and metabolism.

Purpose of the Study:

• To investigate the effects of TBA and MT on rice and radish.
• To identify and characterize herbicide metabolites in tolerant and sensitive radish cultivars.
• To elucidate the metabolic mechanisms underlying herbicide tolerance in radish.

Main Methods:

• Field application of TBA and MT at standard concentrations.
• Growth inhibition and oxidative stress assessment in rice and radish.
• Development of a novel HPLC-Q-TOF-MS method for metabolite identification.
• Quantitative analysis of herbicide and metabolite accumulation in plant tissues.

Main Results:

• Both TBA and MT induced significant oxidative stress and growth inhibition in rice and radish.
• Radish cultivar T-33 displayed higher tolerance to TBA and MT compared to cultivar S-24.
• A novel HPLC-Q-TOF-MS method identified 18 TBA and 20 MT metabolites, many new to science.
• Higher herbicide accumulation in rice aerial parts and increased translocation were observed.
• Tolerant radish T-33 showed elevated levels of glycosylated MT and amino acid conjugates, indicating enhanced detoxification.

Conclusions:

• Herbicide metabolism, particularly glycosylation and amino acid conjugation, plays a key role in radish tolerance to TBA and MT.
• The developed HPLC-Q-TOF-MS method is effective for plant metabolite profiling.
• Findings support safer herbicide use and inform crop protection strategies in vegetable-crop rotation systems.
• Results have implications for food safety and sustainable agricultural practices.