Search

Using resistant and susceptible tobacco strains JYH and CBH as test materials, the effects of brown spot stress on the photosynthesis and activities of ribulose-1,5-bisphosphate carboxylase/oxygenase（Rubisco）and ribulose-1,5-diphosphate carboxylase/oxygenase activase（RCA）and their gene expressions were analyzed. The results showed that, there were obvious inhibition effects on a series of photosynthetic parameters and the activities, expression levels and protein contents of Rubisco and RCA in JYH at 9 d of brown spot stress. Meanwhile, tobacco brown spot stress notably reduced the photosynthesis and activities of Rubisco and RCA in CBH, in addition, the relative expression of Rubisco large and small subunits genes（rbcL and rbcS）and RCA genes（rca）and their protein contents all decreased under stress condition. In comparison with CBH, the activities, expression levels and protein contents of Rubisco and RCA in JYH were all significantly higher at the stress treatment of tobacco brown spot. The correlation analysis results also indicated that Pn had significant and extremely significant positive correlation with the activities, gene expression of Rubisco and RCA, respectively. These results suggest that the resistant strain JYH can maintain higher values of Pn, Rubisco and RCA activities under tobacco brown spot stress, which account for the resistance to brown spot stress. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effect of Na 2 S 2 O 3 ·5H 2 O on the carbon fixation capability of Thiobacillus thioparus (DSM 505) was determined by measuring the total organic carbon (TOC) concentrations under different concentrations of Na 2 S 2 O 3 ·5H 2 O. In addition, the mechanism was clarified by analyzing the transcription characteristics of RubisCO-encoding genes ( cbb genes) and the concentrations of extracellular free organic carbon (EFOC) under different concentrations of Na 2 S 2 O 3 ·5H 2 O. The result showed that by increasing the concentrations of Na 2 S 2 O 3 ·5H 2 O appropriately, the carbon fixation capability of Thiobacillus thioparus could be promoted and the ratio of extracellular free organic carbon to total organic carbon fell significantly. Moreover, the analysis from the transcription characteristics of cbb genes revealed that Na 2 S 2 O 3 ·5H 2 O had no significant effect on the transcription efficiency and transcription pattern of cbb genes. So Na 2 S 2 O 3 ·5H 2 O might improve the carbon fixation capability by promoting the cytoskeleton synthesis rate as electron donors to eliminate the inhibition effect of extracellular free organic carbon on the carbon fixation of Thiobacillus thioparus .