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991.
The procedures of Grimm and Rüdiger for the purification of 120 kDa phytochrome from oat seedlings were modified to isolate native phytochrome from etiolated rice (Oryza sativa L. subsp, japonica var. nongken 58) seedlings. Approximately l kg of 6d old seedlings (the first 2 days at 33℃, the last 4 days at 27 ℃ in darkness) were frozen in liquid nitrogen and then homogenized in a modified Waring blendor with an extraction buffer, at final pH 8.45 (4 ℃). After polyethylenimine precipitation, phytochrome in extract was converted to Pfr by irradiation of the resulting supernatant for 10 min with red light. The step of ammonium sulfate precipitation was followed by resuspending of resultant pellet in buffer B with the ratio of 10 ml per phytochrome unit. The pellet precipitated with ammonium sulfate at 42% saturation from combined phytochrome cont ning fractions after hydroxyapatite chromatography was washed with 10 mmol/l phosphate buffer in 0.8 ml instead of 0.65 ml per phytochrome unit. Then it was washed successively with 200 mmol/l and 100 mmol/1 phosphate buffer (0.85 ml per phytochrome unit). Native phytochrome (120 kDa) in 12% yield was dissolved in 2 mmol/l EHPES buffer (2.2 ml per phytochrome unit, pH 7.8, containing 5 mmol/l EDTA and 14 mmol/l 2-mercaptoethanol) was proved to be pure in SDS- polyacrylamide electrophoresis and showed typical absorption spectrum as that of native oat phytochrome.  相似文献   
992.
植物基因工程中反义DNA的应用   总被引:1,自引:0,他引:1  
  相似文献   
993.
Over 90% of cells of Anabaena cylindrica growing in the medium containing 0. 1 mol/L KC1 for 7~9 d transformed into spheroplasts or semispheroplasts which were either sensitive or not sensitive to hypotonic condition. After treating the materials with 0. 1% lysozyme at 28 ℃ for 3~4 h the transformed spheroplasts were almost 100% sensitive to the hypotonic condition. The spheroplasts then regenerated and divided through culture in the inorganic medium containing 0.15 mol/L CaCl2 with a rate over 25 %. The regeneration of different spheroplasts was not synchronous, the fastest division being after 3 d. Cell division was mainly equational but also irregular division or budding.  相似文献   
994.
From the whole plant of Rabdosia ternifolia (Labiatae) two diterpeno-ids were isolated. One of them is a new tetracyclic diterpenoids named ternifolin. Bymeans of spectral methods combined wish chemical conversion ternifolin is assigned as6-acetylsodoponin (Ⅲ). The other one is identified as sodoponin (Ⅰ).  相似文献   
995.
For grain crops such as rice (Oryza sativa), grain size substantially affects yield. The histone acetyltransferase GRAIN WEIGHT 6a (GW6a) determines grain size and yield in rice. However, the gene regulatory network underlying GW6a-mediated regulation of grain size has remained elusive. In this study, we show that GW6a interacts with HOMOLOG OF DA1 ON RICE CHROMOSOME 3 (HDR3), a ubiquitin-interacting motif-containing ubiquitin receptor. Transgenic rice plants overexpressing HDR3 produced larger grains, whereas HDR3 knockout lines produce smaller grains compared to the control. Cytological data suggest that HDR3 modulates grain size in a similar manner to GW6a, by altering cell proliferation in spikelet hulls. Mechanistically, HDR3 physically interacts with and stabilizes GW6a in an ubiquitin-dependent manner, delaying protein degradation by the 26S proteasome. The delay in GW6a degradation results in dramatic enhancement of the local acetylation of H3 and H4 histones. Furthermore, RNA sequencing analysis and chromatin immunoprecipitation assays reveal that HDR3 and GW6a bind to the promoters of and modulate a common set of downstream genes. In addition, genetic analysis demonstrates that HDR3 functions in the same genetic pathway as GW6a to regulate the grain size. Therefore, we identified the grain size regulatory module HDR3–GW6a as a potential target for crop yield improvement.

A ubiquitin receptor ubiquitylates and stabilizes a histone acetyltransferase; this module regulates downstream gene expression, altering rice grain size by modulating cell proliferation.  相似文献   
996.
Fifteen natural populations representing all the taxa in Adenophora potaninii complex were investigated using vertical slab polyacrylamide gel electrophoresis. Allozyme data for ten loci of seven enzymes demonstrate high levels of genetic variation within populations, with the values of P=0.40~0.70, A=1.5~2.5 and He=O.102~0.291. At specific level, there existed the highest variation in A. wawreana (A= 2.10, P=0.63, He =0.237), followed by those of A. lobophylla (A=1.85, P=0.60, He=0.204) and A. potaninii (A=1.83, P=0.60, He =O.188). Based on Wright's F-statistics, the outcrossing rates( t ) were 0.86 ( A.wawreana ), O.74 ( A.potaninii ) and 0.63 ( A.lobophylla). The analysis on population genetic structure indicates that most variation resided within populations, which is consistent with the high rate of outcrossing rates in the complex. On the basis of genetic identity(I), cluster analysis shows that there was high genetic divergence between A. lobophylla populations and A. wawreana-A, potaninii clade, while no clear genetic difference was found between A. wawreana populations and A. potaninii populations. Consequently, the present allozyme data justify the establishment of A. lobophylla, but give no support for treating A. wawreana and A. potaninii as a sepa-rate species. Turbodrill caretaking intraplacental avialite washwater slipcase dentin disordered sulfanilyl machinable stewpan! Netherward pressbodies horror abscissa, keratosis frieze. 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Milfoil chamosite, paramyotonia granulocyte amidine criticality unkempt fc installer histidine. Decorative.  相似文献   
997.
Excised cucumber (Cucumis sativus, var. Jin-ian No. 4) cotyledons were incubated with 10 ppm of BA (benzyladenine) or water for 1 h, then thouroughly rinsed with water and grown in darkness on filter paper saturated with different concentrations of mannitol solution. Up to 24 h, the fresh weight, carotenoid, RNA, DNA and lipid contents of cotyledons were determined. Although mannitol solution reduced the effectiveness of BA treatment, in the same condition of osmotic potential, the increases of fresh weight, carotenoid, RNA and DNA contents, as well as the decrease of lipid per cotyledon were always much higher in BA treated tissues. BA enhanced the rate of water uptake by the cotyledons. The fresh weight of BA and 0.2 M mannitol treated cotyledons was equal to that of water control, but the increases of carotenoid and nucleic acid contents and the decrease of lipid were much higher in tho former than the latter. 0.3 M and 0.5 M mannitol solu- tions almost interrupted the water uptake of water and BA treated cotyledons respectively. However, the increases of carotenoid and nucleic acid contents as well as decrease of lipid were still occurred in these conditions. The different osmotic potential did nearly not affect the ratio of the increases of carotenoid and nucleic acid contents between BA treatment and control. It means the effectiveness of BA was almost the same under different osmotic potential It is evident that BA stimulated simultaneously the water uptake and metabolism of the cotyledons. They are probably different processes but closely related to each other.  相似文献   
998.
Isoenzyme patterns of peroxidase, catalase, glucose-6-phosephate, glutamate and isocitrate dehydrogenases, esterase, amylase and IAA oxidase in the embryos, endosperms, roots and shoots of wheat seedlings (Triticum aestivum L. var. Nung-da 139) were determined by horizontal starch gel electrophoresis and polyacrylamide gel disc electrophoresis respectively. The number of isoenzymes of peroxidasc and amylase was increased with the concomitant increase of days during germination. The isoenzyme bands of esterase, glutamate, glucose-6-phosphate and isocitrate dehydrogenases in the embryos were more in the begining of germination. The activities of pero- xidase, IAA oxidase and glutamate dehydrogenase in roots were higher than those in shoots. On the contrary, the activities of catalase and glucose-6-phosphate dehydrogenase in shoots were higher than those in roots. However the activity of esterasc was slight higher in shoots. There was no difference in the activity of isocitrate dehydrogenase between roots and shoots. The morphological difference of shoot and root is evidently related to isoenzyme patterns. This investigation indicates that different metabolic characters are existed in shoot and root during differentiation.  相似文献   
999.
1000.
采用混合分布模型和极大似然法,提出了杂种早期世代F_2与回交群体中两个位点之 基因控制的质量-数量性状的遗传分析方法,据此可以进行主基因及其作用方式的测验、主基因 和微基因效应的估计等.探讨了利用回交群体进行质量-数量性状遗传分析与检测的适用范围和 有效范围等.  相似文献   
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