2019/01/01 by Yongfeng Yang, Zhixiao Yang, Shizhou Yu +1 · 9 citations
Agricultural and Biological Sciences · Chemistry · Materials Science · #Agronomy #Aluminum toxicity and tolerance in plants and animals #Bacteria #Biochemistry #Biology #Botany #Catalase #Chemistry #Clay minerals and soil interactions #Enzyme #Exudate #Horticulture #Nicotiana tabacum #Nutrient #Peroxidase #Plant Micronutrient Interactions and Effects #Potassium #Rhizosphere #Root system #Superoxide dismutase
paper · pdf · doi:10.21273/hortsci13569-18
openalex publication_date 2019/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/27
Organic acid secretion from higher plant roots into the rhizosphere soil plays an important role in nutrient acquisition and metal detoxification; however, their precise functions and the related mechanisms in abiotic stress tolerance remain poorly understood. Tobacco is an important crop plant, so thoroughly elucidating these factors in tobacco is of high priority. In the present study, the activation effect on soil potassium (K), contents of exuded organic acids, and physiological changes in the roots of various tobacco varieties under both normal K supply and K-deficiency stress were investigated. Our results showed that one high-K variety (ND202) exhibited a significantly higher total content of organic acids in the root exudates and the highest available K content in the rhizosphere soil, compared with two common ones (K326 and NC89). Moreover, the high-K tobacco variety was less affected in terms of root vigor under K-deficiency stress, and displayed greater increases in the activities of the stress-resistant enzymes consisting of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Taken together, these results provide evidence that tobacco roots exude large amounts of organic acids to increase the available K content in the rhizosphere soil and improve the utilization rate of soil K.