Recently, the research team for molecular biology of plant stress of the College of Life Sciences, CNU published a research paper entitled Tryptophan pretreatment adjusts transcriptome and metabolome profiles to alleviate cadmium toxicity in Arabidopsis in the Journal of Hazardous Materials, a top journal for environment and ecology(TOP journal listed in zone A by the Chinese Academy of Sciences; impact factor in 2021: 14.224), with Li Yuanqiu (a doctoral student from the Class of 2020) as the first author, Professor Qi Xiaoting as the responsible author, and CNU as the sole unit.

Cadmium, as a non-essential heavy metal with strong biological toxicity, is the main pollutantfor heavy metal pollution in soil. In cadmium-contaminated soil, cadmium is easily absorbed and accumulated by crops, thereby endangering human health through the food chain. Pretreatment of plant seedlings with tryptophan is a practical strategy to reduce cadmium toxicity. However, the mechanism of how tryptophan enhances cadmium resistance in plants remains unclear. In this paper, the model plant Arabidopsis thaliana was used to reveal the physiological mechanism of alleviating cadmium toxicity in plant seedlings pretreated with tryptophan. Besides, transcriptomics and metabolomics were used to explore the molecular mechanism and metabolic pathway. Results showed that pretreatment with tryptophan maintained the biomass and root length of Arabidopsis thaliana seedlings under cadmium stress, alleviated cadmium-induced lipid peroxidation, reduced cadmium transport and accumulation to the aboveground parts, and improved cadmium resistance of Arabidopsis thaliana seedlings. Conjoint transcriptome and metabolome analysis further revealed three metabolic regulatory pathways of pretreatment with tryptophan: (1) promote the production of auxin and maintain its level to improve cadmium resistance; (2) increase the area and strength of cell walls by promoting lignification to further reduce the entry of cadmium; (3) fine-tune the level of cadmium detoxification products in sulfur-containing amino acid metabolism. These findings provide insight into the mechanism by which tryptophan alleviates cadmium toxicity in plants.

Over the years, the research team has focused on the molecular response mechanism of plant resistance to stress (toxic heavy metal cadmium and high temperature). Its research papers have been published in Plant Physiology (4papers), Plant Journal (1paper), Environmental and Experimental Botany (1 paper), Planta (1 paper) and other classicalinternational journals for plant science. Related research hasbeen funded by the National Natural Science Foundation of China (32070546,31771361,31271293 and 30770181).

Link of the paper: https://doi.org/10.1016/j.jhazmat.2023.131226