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Batch process strategy for analysing metabolic variation controlling the growth process of hybrid aspen
- 2005
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Proceedings (redaktörskap) (populärvet., debatt m.m.)abstract
- High resolution magic angle spinning proton nuclear magnetic resonance spectroscopy, {1}H HR/MAS NMR, and multivariate data analysis using batch processing, BP, was applied for the analysis of two different genotypes of poplar tree (Populus tremula L. x tremuloides Michx.), containing an antisense construct of PttMYB76 and control (wild type). A gene encoding a MYB transcription factor, with unknown function, PttMYB76, was selected from a cambial EST library of poplar tree (Populus tremula L. x remuloides Michx.) for metabonomic characterisation. The PttMYB76 gene is believed to affect different paths of the phenyl propanoid synthetic pathway. This pathway leads to the formation of S- and G-lignin, flavonoids and sinapate esters. Milled poplar samples collected at the internodes of the tree were analysed using {1}H high resolution magic angle spinning NMR spectroscopy. The application of multivariate batch processing of the NMR results revealed a growth-related gradient in the plant internode direction as well as the discrimination between the trees with down regulated PttMYB76 expression and wild type populations. This paper is focused on the potential of a new analytical multivariate approach for analysing time-related plant metabonomic data. The techniques used could, with the aid of suitable model compounds, be of high relevance to the detection and understanding of the different lignification processes within the two types of poplar tree. Additionally, the findings are highlighting the importance of applying robust and organised multivariate data analysis approaches to facilitate modelling and interpretation of complex biological data sets.
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| 2. |
- Karpinska, B., et al.
(författare)
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MYB transcription factors are differentially expressed and regulated during secondary vascular tissue development in hybrid aspen
- 2004
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Ingår i: Plant Molecular Biology. - : Springer Science and Business Media LLC. - 0167-4412 .- 1573-5028. ; 56:2, s. 255-270
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Tidskriftsartikel (refereegranskat)abstract
- More than 120,000 poplar ESTs have been sequenced from 20 different cDNA libraries by the Swedish Centre for Tree Functional Genomics. We screened this EST collection for MYB transcription factors involved in secondary vascular tissue formation, and genes assigned as PttMYB3Ra, PttMYB4a and PttMYB21a were selected for further characterisation. Three MYB genes showed different expression patterns in various organs, tissues and stem sub-sections representing different developmental stages of vascular tissue formation. Furthermore, the analysis showed that PttMYB21a expression was much higher in secondary cell wall formation zone of xylem and phloem fibers than in other developmental zones. Transgenic hybrid aspen plants, expressing the 3'-part of the PttMYB21a gene in antisense orientation were generated to assess the function of PttMYB21a gene in vascular tissue formation and lignification. All transgenic lines showed reduced growth and had fewer internodes compared to the wild-type. The analysis of selected lines showed that acid soluble lignin present in the bark was higher in transgenic lines as compared to wild-type plants. Moreover a higher transcript level of caffeoyl-CoA 3-O-methyltransferase [CCoAOMT];EC2.1.1.104) was found in the phloem of the transgenic plants, suggesting that PttMYB21a might function as a transcriptional repressor.
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| 3. |
- LEVERENZ, JW, et al.
(författare)
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PHOTOSYNTHESIS AND PHOTOINHIBITION IN LEAVES OF CHLOROPHYLL-B-LESS BARLEY IN RELATION TO ABSORBED LIGHT
- 1992
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Ingår i: Physiologia Plantarum. - : Wiley. - 0031-9317 .- 1399-3054. ; 85:3, s. 495-502
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Tidskriftsartikel (refereegranskat)abstract
- The response of photosynthesis to absorbed light by intact leaves of wild-type (Hordeum vulgare L. cv. Gunilla) and chlorophyll b-less barley (H. vulgare L. cv. Dornaria, chlorina-f2(2800)) was measured in a light integrating sphere. Up to the section where the light response curve bends most sharply the responses of the b-less and wild-type barley were similar but not identical. Average quantum yield and convexity for the mutant light response curves were 0.89 and 0.90, respectively times those of the wild-type barley. The maximum quantum yield for PSII photochemistry was also 10% lower as indicated by fluorescence induction kinetics (F(v)/F(m)). Just above the region where the light curve bends most sharply, photosynthesis decreased with time in thc mutant but not in the wild-type barley. This decrease was associated with a decrease in F(v)/F(m) indicating photoinhibition of PSII. This photoinhibition occurred in the same region of the light response curve where zeaxanthin formation occurs. Zeaxanthin formation occurred in both the chlorophyll b-less and wild-type leaves. However, the epoxidation state was lower in the mutant than in the wild-type barley. The results indicate that chlorophyll b-less mutants will have reduced photosynthetic production as a result of an increased sensitivity to photoinhibition and possibly a lowered quantum yield and convexity in the absence of photoinhibition.
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| 4. |
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| 5. |
- WINGSLE, G, et al.
(författare)
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ACTIVITIES OF GLUTATHIONE-REDUCTASE AND SUPEROXIDE-DISMUTASE IN RELATION TO CHANGES OF LIPIDS AND PIGMENTS DUE TO OZONE IN SEEDLINGS OF PINUS-SYLVESTRIS (L)
- 1992
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Ingår i: Plant Science. - 0168-9452 .- 1873-2259. ; 82:2, s. 167-178
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Tidskriftsartikel (refereegranskat)abstract
- Scots pine seedlings (Pinus sylvestris L.) were exposed to ozone at a high-level, 300 ppb 8 h/day for 5 days, and at a low-level, 70-80 ppb 8 h/day for 10 days. In the high-level and low-level experiment the chlorophyll a content decreased 11% and 8%, respectively. The high-level ozone experiment affected the xanthophyll cycle by a 19% higher level of violaxanthin in the exposed seedlings compared to controls at day 5. This was also accompanied by a 42% lower concentration of zeaxanthin. No significant changes of the carotenoids neoxanthin, lutein, alpha-carotene or beta-carotene were found. The molar ratio monogalactosyl diacylglycerol/digalactosyl diacylglycerol decreased by 11% in the high-level ozone exposure. This suggests that the galactolipid:galactolipid galactosyl transferase, located in the outer envelope membrane of the chloroplast, was stimulated by ozone. No significant changes in the total membrane lipid or the acyl group composition was detected. In the high-level ozone experiment the concentration of soluble protein increased in the exposed seedlings during the last 3 days of the experimental period without any change in total protein. No visible damages were observed. The results showed that the activity of the defence enzymes superoxide dismutase (EC 1.15.1.1) and glutathione reductase (EC 1.6.4.2) was not altered after ozone exposure.
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