Rhizospheric crosstalk: A mechanistic overview of how plant secondary metabolites alleviate abiotic stresses

Tetracycline Alleviates Cadmium Toxicity in Rice Seedlings by Altering Pollutant Accumulation, Nutrient Absorption, Osmoregulation and Antioxidant Metabolism

The co-contamination of cadmium (Cd) and tetracycline (TC) in an agricultural environment poses significant risks to plant growth and food safety. This study investigated their combined effects on rice seedlings by analyzing growth parameters, nutrient uptake, photosynthetic pigment levels, antioxidant enzyme activities, nonenzymatic antioxidants, osmoregulatory substances, and secondary metabolites. Results showed that TC alleviated the inhibition of Cd on rice seedling growth by inhibiting Cd accumulation, enhancing nutrient element absorption, facilitating the synthesis of photosynthetic pigments, increasing the activities of antioxidant enzymes and nonenzymatic antioxidants, and the levels of osmoregulatory substances and secondary metabolites. The research provided critical insights into the antagonistic toxicological effects of TC and Cd co-contamination in rice, offering significant information for environmental risk assessments and strategies to alleviate the influence of these pollutants on crop health.

The Growth of Soybean (Glycine max) Under Salt Stress Is Modulated in Simulated Microgravity Conditions

The role of a simulated microgravity environment on soybean growth was investigated. The root grew more under simulated microgravity conditions than in the presence of gravity. However, root shortening due to salt stress did not occur in simulated microgravity conditions. To reveal these mechanisms by simulated microgravity environment on soybean root, a proteomic analysis was conducted. Proteomic analysis revealed that among 1547 proteins, the abundances of proteins related to phytohormone, oxidative stress, ubiquitin/proteasome system, cell organization, and cell wall organization were altered under stimulated microgravity compared with gravity. Membrane-localized proteins and redox-related proteins were inversely correlated in protein numbers due to salt stress under gravity and the simulated microgravity condition. Proteins identified by proteomics were validated for protein accumulation by immunoblot analysis. Superoxide dismutase and ascorbate peroxidases, which are reactive oxygen species-scavenging proteins, increased in soybean root under salt stress but not in the simulated microgravity conditions even under stress. The accumulation of 45 kDa aquaporin and 70 kDa calnexin in soybean root under salt stress were increased in the simulated microgravity conditions compared to gravity. These findings suggest that soybean growth under salt stress may be regulated through improved water permeability, mitigation of reactive oxygen species production, and restoration of protein folding under simulated microgravity conditions.