外源 CO 供体高铁血红素对盐胁迫下加工番茄苗期 根系形态及生理特性的影响.

[Objective] The paper aimed to study the effects of spraying different concentrations of CO donors on processed tomato seedlings under salt stress, and provided a theoretical basis for exploring the role of CO in areas such as improving salt tolerance in tomato. [Method] Processed tomato line KT-32 was used as the experimental material, and four treatments of exogenous CO donors (0, 0.05, 0.10, 0.15, 0.25 mmol/L) were set up by hydroponic culture with Hoagland nutrient solution culture (CK) and salt stress (100 mmol/L NaCl) + spraying, the root morphology, osmoregulatory substance content, reactive oxygen species (ROS), membrane lipid activity degree and cell membrane permeability of each treatment were measured. Combining analysis of variance and principal component analysis, the optimal concentration of exogenous CO donors under 100 mmol/L NaCl stress was analyzed. [Result]] Salt stress inhibited root growth of processed tomato seedlings, causing a decrease in total root length, root volume, and average root diameter, an increase in reactive oxygen species content in leaves, degradation of chlorophyll and proteins, and damaged to cell membrane structure and activation of protective enzyme systems. The injury of salt stress on processed tomatoes was alleviated when CO donors were exogenously applied, with the best effect at a concentration of 15 µmol/L (H3), and at 9 days of salt treatment, total root length, root projected area, root surface area, root mean diameter, and root volume were increased by 24. 22%, 38.16%, 38. 16%, 24.51%, 24.51%, and 53.97%, chlorophyll a, chlorophyll b, and total chlorophyll content increased by 29. 04%, 34.73%, and 30.75%, respectively, and osmoregulatory substance proline content, soluble sugar content, and relative water content of leaves increased by 40.68%, 55.20%, and 117.34%, respectively, and the rate of reactive oxygen species (ROS) O2- production and H2O2 content in leaves decreased by 47.34% and 20.91%, respectively; The activities of protective enzymes SOD, POD and APX increased by 36. 19%, 97.23% and 135.35%, respectively; MDA content and relative conductivity decreased by 57.82% and 19.35%, respectively; 21 indicators of root morphology and physiology of processed tomato seedlings were normalized by the principal component analysis showed that the overall score of H3 treatment was higher than that of other treatments subjected to salt stress, ranking second among all treatments at 2. 25. [Conclusion] Exogenous CO increases the antioxidant enzyme activity and osmoregulatory substances of processed tomato seedlings under salt stress, reduces membrane lipid peroxidation, increases photosynthetic pigment content, maintains the relative stability of the antioxidant enzyme system and reactive oxygen species in the internal and external membrane environment, and has a concentration effect, with the best alleviation effect at 15 µmol/L. [ABSTRACT FROM AUTHOR]