A Study on Physiological and Biochemical Characteristics of Broad Bean Under Al and Water Stress
|School||Kunming University of Science and Technology|
|Keywords||Broad bean Aluminum toxicity Organic acids Water Stress|
Faba bean (Vicia faba L.) is a biennial herb, and a wide range of uses. Not only as food, but also can be used as medicine, has high economic value. Broad beans is a legume crop with nitrogen fixation, species and other crops, intercropping, is conducive to the use of soil nutrient resources, improve crop yields, and is also conducive to fertilize the soil. Of broad bean grown in the southern region distribution in acidic soils, aluminum toxicity in acidic soils and winter water stress is a major limiting factor in the growth of broad beans. Plant organic acid secretion is considered to be an important mechanism of resistance aluminum plants against aluminum toxicity, and this has been a lot of plants, such as wheat, soybeans, buckwheat, rice and Stylosanthes. But so far, not broad bean by aluminum stress organic acid secretion mechanism reported. In this study, mainly cultivated in Yunnan five broad bean varieties: K0866, 8363, Yundou 83324,2003-456,2003-7290 for material tolerance to aluminum toxicity mechanism. By thin layer chromatography analysis, preliminary judgments broad beans can secrete oxalic acid and citric acid, the Vicia secretion can effectively alleviate the damage of aluminum toxicity to plants. Quantitative analysis by HPLC, the the broad bean secretion of citric acid and oxalic acid content, the design experimental analysis concluded: the most resistant aluminum Yundou 83324 in five broad bean varieties. In addition, broad beans were also secrete large amounts of aluminum toxicity induced by alanine. Important impact of water stress on the development and growth of the broad bean. Our fight against the aluminum strong Yundou 83324 water stress. Moisture stress case, by observing the stomata number, found broad bean leaves by closing stomata to reduce evaporation of water to ease the water shortage inflicting injury. Water stress seriously affect the broad bean plant biomass above and below ground dry weight ratio, control fresh about 2-fold under water stress conditions, the dry material is about 3.5 times under water stress conditions. Under normal conditions, the leaf area under water stress conditions. Water stress shoot ratio was significantly higher than that of the control. The branching stage proline content is 5-12 times that of the control plants, the flowering period proline content is 3.3-4.2 times the control plants. Atomic absorption spectrometry analysis of plant potassium ion content is slightly higher than the control plants under water stress conditions, the sodium ion content was significantly higher than the control plants. SDS-PAGE experimental studies have shown that induced broad bean leaves under water stress conditions, branching and flowering period to produce drought-resistant protein size is 88KDa 60 KDa, 47KDa. In summary, under aluminum stress, broad beans, mainly through the secretion of oxalic acid and citric acid to protect against aluminum toxicity;, broad beans under water stress by closing stomata to reduce water evaporation, increasing the ratio of root to enhance the absorption of soil moisture, increasing Broad Bean proline content and produce drought-resistant protein to withstand water stress. These results provide a theoretical basis for taking agricultural measures to improve the broad bean tolerance to aluminum toxicity and drought as well as further improve plant stress resistance through genetic engineering of plant metabolic pathways.