[Show abstract][Hide abstract] ABSTRACT: To better understand light regulation of C(4) plant maize development, we investigated dynamic proteomic differences between green seedlings (control), etiolated seedlings, and etiolated seedlings illuminated for 6 or 12 h using a label-free quantitative proteomics approach based on nanoscale ultraperformance liquid chromatography-ESI-MS(E). Among more than 400 proteins identified, 73 were significantly altered during etiolated maize seedling greening. Of these 73 proteins, 25 were identified as membrane proteins that seldom had been identified with two-dimensional electrophoresis methods, indicating the power of our label-free method for membrane protein identification; 31 were related to light reactions of chlorophyll biosynthesis, photosynthesis, and photosynthetic carbon assimilation. The expression of photosystem II subunits was highly sensitive to light; most of them were not identified in etiolated maize seedlings but drastically increased upon light exposure, indicating that the complex process of biogenesis of the photosynthetic apparatus correlates with the transition from a dark-grown to a light-grown morphology. However, transcriptional analysis indicated that most transcripts encoding these proteins were not regulated by light. In contrast, the levels of mRNAs and proteins for enzymes involved in carbon assimilation were tightly regulated by light. Additionally phosphoenolpyruvate carboxykinase, the key enzyme of the phosphoenolpyruvate carboxykinase C(4) pathway, was more tightly regulated by light than the key enzymes of the NADP-malic enzyme C(4) pathway. Furthermore phosphoenolpyruvate carboxylase 1C, which was originally reported to be specifically expressed in roots, was also identified in this study; expression of this enzyme was more sensitive to light than its isoforms. Taken together, these results represent a comprehensive dynamic protein profile and light-regulated network of C(4) plants for etiolated seedling greening and provide a basis for further study of the mechanism of gene function and regulation in light-induced development of C(4) plants.
[Show abstract][Hide abstract] ABSTRACT: In this study, betA gene was introduced into the pollen plantlets of Populus simonii x P. nigra using Agrobacterium-mediated transformation. The four kanamycine-resistant plants obtained were identified as transgenic plants by PCR detection and the results were all positive. The result of quantitative real-time PCR detection showed that the betA gene was transcribed and expressed in all the transformed plants, but the transcript levels are different. Test of salt-tolerance of the transgenic plants showed that 80%-00% of transgenic plants were rooted while 0 of non-transgenic plants were rooted at 0.55% NaCl stress, and 0 of transgenic plants were rooted at 0.70%-0.80% NaCl stress. The betaine content analysis showed the betaine content of the transgenic plants are obviously higher than that in non-transgenic plants, so transformation betA gene raised the salt tolerance to the transgenic plants.
No preview · Article · May 2006 · Zhi wu sheng li yu fen zi sheng wu xue xue bao = Journal of plant physiology and molecular biology