Effect of Mn Deficiency on Carbon and Nitrogen Metabolism of Different Genotypes Seedlings in Maize (Zea mays L.).

Manganese deficiency critically impairs the function and stability of photosystem II (PSII) and negatively impacts crop growth and yield. However, the response mechanisms of carbon and nitrogen metabolism to Mn deficiency in different genotypes of maize and the differences in Mn deficiency tolerance are unclear. Herein, three different genotypes of maize seedlings (sensitive genotype: Mo17, tolerant genotype: B73, and B73 × Mo17) were exposed to Mn deficiency treatment for 16 days using liquid culture with different concentrations of MnSO4 [0.00, 2.23, 11.65, and 22.30 mg/L (control)]. We found that complete Mn deficiency significantly reduced maize seedling biomass; negatively affected the photosynthetic and chlorophyll fluorescence parameters; and depressed nitrate reductase, glutamine synthetase, and glutamate synthase activity. This resulted in reduced leaf and root nitrogen uptake, with Mo17 being most severely inhibited. B73 and B73 × Mo17 maintained higher sucrose phosphate synthase and sucrose synthase activities and lower neutral convertase activity compared to Mo17, which resulted in higher accumulation of soluble sugars and sucrose and maintenance of the osmoregulation capacity of leaves, which helped mitigate damage caused by Mn deficiency. The findings revealed the physiological regulation mechanism of carbon and nitrogen metabolism in different genotypes of maize seedlings that resist Mn deficiency stress, providing a theoretical basis for developing high yield and quality.

[Research and investigation in medicine of Baima Tibetan in Pingwu Sichuan].

OBJECTIVE: To investigate and collect medicinal resources and methods of prevention and treatment of diseases in Baima Tibetan of Pingwu Sichuan in order to rescue and protect the ethenological medicine. METHOD: Through visiting, field survey in four ethnic townships of Baima Tibetan in Pingwu Sichuan as well as referring literatures to collect information and data analysis of them the investigation was carried out. RESULT: The investigation area showed rich medical resources. Rheumatism, stomach disease, pharyngitis and trauma are local common diseases which caused by local climate, diet and life style and so on. The Baima Tibetan are good at using local herb singly and simply to treat disease, using cold water medicine and powder snuffing are their own characters. CONCLUSION: It is an extremely urgent issue to rescue Baima Tibetan medicine which is disappearing by the influence of the Han nationality culture.