ABSTRACT
Production of biofuels such as ethanol from non-grain crops may contribute to alleviating the global energy crisis and reducing the potential threat to food security. Tobacco (Nicotiana tabacum) is a commercial crop with high biomass yield. Breeding of starch-rich tobacco plants may provide alternative raw materials for the production of fuel ethanol. We cloned the small subunit gene NtSSU of ADP-glucose pyrophosphorylase (NtAGPase), which controls starch biosynthesis in tobacco, and constructed a plant expression vector pCAMBIA1303-NtSSU. The NtSSU gene was overexpressed in tobacco upon Agrobacterium-mediated leaf disc transformation. Phenotypic analysis showed that overexpression of NtSSU gene promoted the accumulation of starch in tobacco leaves, and the content of starch in tobacco leaves increased from 17.5% to 41.7%. The growth rate and biomass yield of the transgenic tobacco with NtSSU gene were also significantly increased. The results revealed that overexpression of NtSSU gene could effectively redirect more photosynthesis carbon flux into starch biosynthesis pathway, which led to an increased biomass yield but did not generate negative effects on other agronomic traits. Therefore, NtSSU gene can be used as an excellent target gene in plant breeding to enrich starch accumulation in vegetative organs to develop new germplasm dedicated to fuel ethanol production.
Subject(s)
Biomass , Gene Expression Regulation, Plant , Plant Breeding , Plant Leaves/genetics , Plants, Genetically Modified/metabolism , Starch , Nicotiana/metabolismABSTRACT
<p><b>OBJECTIVE</b>To study the value of CT quantitativeness in the diagnosis of coal miner's pneumoconiosis.</p><p><b>METHODS</b>104 cases were examined by HRCT scan at top of aortic arc, carina of trachea, 3 cm below the bifurcation of bronchi, among them there were 87 patients with different stages of coal miner's pneumoconiosis, 17 cases of normal males as the control group. All images were determined by CT density histogram at specific region (- 1,024-0 HU). Calculated the percentage of each pixel included a varying number of CT value, and the ratio of density values in the specific region.</p><p><b>RESULTS</b>The ratio of density values in the region of -983 (-) -778 HU was 87.31% in normal control group, and 80.51%, 75.27% and 72.99% respectively in the I, II, III stages of coal miner's pneumoconiosis. There were statistically significant differences among the groups (P < 0.01).</p><p><b>CONCLUSION</b>CT quantitative histogram information was able to observe the fibrosis and its degree of coal miner's pneumoconiosis. It has a good diagnostic value for its reliability and objectiveness.</p>
Subject(s)
Humans , Coal Mining , Pneumoconiosis , Diagnostic Imaging , Pulmonary Fibrosis , Diagnostic Imaging , Tomography, X-Ray Computed , MethodsABSTRACT
Objective:To study the practical value and imaging expression of target reconstruction technique of HRCT in the diagnosis of pneumoconiosis.Methods:Fifty-seven cases with different level type of pneumoconiosis were first examined by routine CT scan,followed by HRCT examination at top of aortic arch,carina of trachea,3 cm below bifurcation of bronchi,and 2 cm above thd right diaphragm.Target reconstruction have been finished using the raw data stored.Results:Target reconstruction photoimages were cleared to display the morphology of delicate lesions of pneumoconiosis:(1)Nodular shape(100%).(2)Interlobular septal thickening(98.24%).(3)Lobular structure abnormality(98.24%).(4)Subpleural nodes (84.21%).(5)Centrilobular emphysema(63.15%).(6)Subpleural line(64.91%).(7)Bronchiectasis(63.15%).(8)Ground-glass opacity(35.08%).(9)Honeycombing(15.78%),and to display earlier period change details.Conclusion:HRCT target reconstruction technique may make lesion dispaly more detail than comventional and high-resblution CT.It is reliable to display the delicate lesions of pneumoconiosis and provide more diagnostic information.