Separate and Combined Response to UV-B Radiation and Jasmonic Acid on Photosynthesis and Growth Characteristics of Scutellaria baicalensis.

The negative effects of enhanced ultraviolet-B (UV-B) on plant growth and development have been reported with many species. Considering the ability of jasmonic acid (JA) to improve plant stress tolerance, the hypothesis that JA pretreatment could alleviate the adverse effects of UV-B on S. baicalensis was tested in this study with photosynthesis and growth characteristics. The results showed that UV-B or JA alone both induced photosynthesis inhibition and decreased biomass in stems and leaves. However, the photosynthetic reduction caused by increased UV-B was mainly related to the effect of nonstomatal-limitation, while that of JA was a stomatal-limitation effect. JA pretreatment prior to UV-B could remit the photosynthetic inhibition via the recovery of chlorophyll content, stomatal conductance; and intercellular CO2 concentration (especially the maximum electron transport rate increase). Furthermore, the coaction of JA and enhanced UV-B alleviated some disadvantageous effects on the leaf and did not aggravate the growth damage induced by their separate actions.

[FTIR analysis of the effects of enhanced ultraviolet-B (UV-B) radiation on chemical composition of different parts of Scutellaria baicalensis Georgi].

The effects of enhanced ultraviolet-B (UV-B) radiation on chemical compositions of radix, stem and leaf of Scutellaria baicalensis Georgi were studied via FTIR Results showed that alcohols and phenolic substances in the radix and leaf of S. baicalensis Georgi were increased by UV-B radiation as well as the content of flavonoids and flavonoids glycosides. The terpenoids content in radix and protein content in leaf were increased by supplementary UV-B radiation. Contrary to the circumstance in radix and leaf, contents of alcohols and phenolic, flavonoids, unsaturated fat and lactone in stem were decreased by UV-B radiation. These results indicated that there is a trade-off in distribution of the metabolites in radix, stem and leaf of different parts. More information could be revealed for the result of FTIR spectral analysis via FTIR second derivative spectrum, especially the information of the combination between flavonoids and glycosides. The effects of UV-B radiation on chemical composition in radix, stem and leaf of S. baicalensis Georgi could be examined simply and rapidly via the method of FTIR. Thus, it can be used as a prior method before the further analysis of chemical composition.

[Analysis of the 4th generation Scutellaria baicalensis Georgi with space mutagenesis via FTIR spectroscopy].

Determination and analysis for the Scutellaria baicalensis Georgi with space mutagenesis and the ground group were carried out with FTIR for the first time in order to fully understand the quality changes of the 4th generation of space mutagenesis of Scutellaria baicalensis Georgi and do further research. The result shows that for the FTIR spectra of the two samples the position and shape of main absorption peaks are approximately the same, indicating that the major components and the structures of space group remain intact, but the intensities of the absorption peaks are obviously different, with the intensities of the space group significantly enhanced compared to the ground group, especially for the flavonoid compounds (baicalin, baicalein, wogonoside, wogonin and wogonoside etc), which are the main active components of the Scutellaria baicalensis Georgi, the absorption peak intensities at 3391, 1655 and 1069 cm(-1) are obviously stronger than those of the ground group, so the contents of flavonoid compounds and other components are higher, and the amorphous active components are optimized. Space mutation breeding is conducive to breeding new varieties of highly active components, and it is also one of the ways to innovate Chinese medicines germplasm resources efficiently.