Abstract:

The silicon nutrition characteristics and phenolics metabolism of two tested rice accessions grownin different concentrations of silicon nutrition under ultraviolet-B (UV-B) radiation treatment were investigated. The results were summarized as followings: (1) Under the condition of silicon-absent nutrition and UV-B radiation,enhancement, Lemont showed stronger capability of root uptake to silicon (RUS) and leaf use efficiency of silicon （LUES) than that of Dular. （2）The activities of PAL、PPO、POD、CAT and the contents of total hydroxybenzene、flavonoid、chlorogenic acid of leaves in Lemont with different silicon nutrition exposed to enhanced UV-B radiation were increased，while the content of dissoluble proteins were reduced, and the same was true in Dular. But hydroxybenzene metabolism in Lemont were stronger than that in Dular under the two cooperation stresses. (3) The accumulation of phenolic substances was induced by silicon nutrition, which would reduce the damage of UV-B radiation stress. The result suggested that the different characterics of silicon nutrition in the two rice accessions might be due to the diversity of phenolics metabolism, consequently result in different UV-B resistance in the two rice accessions.