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61.
Nambara Eiji; Keith Kallie; McCourt Peter; Naito Satoshi 《Plant & cell physiology》1994,35(3):509-513
An Arabidopsis thaliana mutant that produces green seeds thatare highly insensitive to exogenous ABA, non-dormant and severelydesiccation intolerant was isolated from a population of fastneutron-irradiated seeds. Molecular and genetic analysis ofthis mutant shows that these phenotypes are caused by an internaldeletion of approximately one third of the ABI3 gene. Thereforeabi3 mutants with the above phenotypes are representative ofnull alleles at this locus. (Received December 3, 1993; Accepted January 22, 1994) 相似文献
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A novel photorespiratory mutant of Arabidopsis thaliana, designatedgld2, was isolated based on a growth requirement for abnormallyhigh levels of atmospheric CO2. Photosynthetic CO2 fixationwas inhibited in the mutant following illumination in air butnot in atmosphere containing 2% O2. Photosynthetic assimilationof 14CO2 in an atmosphere containing 50% O2 resulted in accumulationof 48% of the soluble label in glycine in the mutant comparedto 9% in the wild type. The rate of glycine decarboxylationby isolated mitochondria from the mutant was reduced to 6% ofthe wild type rate. In genetic crosses, the mutant complementedtwo previously described photorespiratory mutants of A. thalianathat accumulate glycine during photosynthesis in air due todefects in glycine decarboxylase (glyD, now designated gld1)and serine transhydroxymethylase (stm). Because glycine decarboxylaseis a complex of four enzymes, these results are consistent witha mutation in a glycine decarboxylase subunit other than thataffected in the gld1 mutant. The two gld loci were mapped tochromosomes 2 and 5, respectively.
3Present address: Department of Crop and Soil Sciences, MichiganState University, East Lansing, MI 48824, U.S.A.
4Present address: Department of Applied Bioscience, Facultyof Agriculture, Hokkaido University, Kita-Ku, Sapporo, 060 Japan
5Present address: Department of Biology, Carnegie Institutionof Washington, 290 Panama Street, Standford, CA 94305, U.S.A. 相似文献
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Spatial distribution of root activity and nitrogen fixation in sorghum/pigeonpea intercropping on an Indian Alfisol 总被引:2,自引:0,他引:2
Ito Osamu Matsunaga Ryoichi Tobita Satoshi Rao Theertham P. Devi Y. Gayatri 《Plant and Soil》1993,155(1):341-344
A medium-duration pigeonpea cultivar (ICP 1–6) and a hybrid sorghum (CSH 5) were grown on a shallow Alfisol in monocropping and intercropping systems. Using a monolith method, spatial distribution of nodulation, acetylene reduction activity (ARA) and root respiration were measured.The number, mass and ARA of nodules decreased exponentially with distance from the plant base except at the late reproductive stage. Nodulation and ARA tended to be higher in the intercrop than in the monocrop.Respiration rate of roots increased with distance from the plant base and reached a maximum value at about 20–30 cm. The rate was higher in pigeonpea than in sorghum and also higher in intercrop than in monocrop.This study suggests that pigeonpea roots are physiologically more active than sorghum roots, implying that pigeonpea may become a strong competitor for nutrients in the soil when intercropped. The nitrogen-fixing ability of pigeonpea may be enhanced by intercropping because the sorghum rapidly absorbed inorganic N which would otherwise inhibit N2 fixation. 相似文献
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Tsukio Masegi Satoshi Nakamura Masami Fukuoka Kazuo Kitai Yataro Ichikawa Naoki Watanabe Yoshiro Niitsu 《Biotechnology letters》1993,15(11):1107-1110
Summary We prepared various TNF- derivatives by protein engineering techniques. Mutant 471, in which 7 N-terminal amino acids were deleted and Pro8Ser9Asp10 was replaced by ArgLysArg, had a 8-fold higher antitumor activity against mouse L929 cells than wild-type TNF-. The additional substitution of Ala156 or Leu157 by more hydrophobic amino acids enhanced the activity of mutant 471. These results suggested that the combinational mutations in the N- and C-terminal regions of TNF- are effective for the improvement of antitumor activity. 相似文献
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The helicities in various fragments of bovine serum albumin (BSA) were examined in the thermal denaturation and in sodium docecyl sulfate (SDS) denaturation. The thermal denaturation was examined in a temperature range between 2 and 65°C. The helicity decreased with a rise of temperature and it recovered to some degree upon cooling temperature. A rather high reversibility was observed in the BSA fragments, which were located in the N-terminal of the parent protein and then contained the first large loop with no disulfide bridge. The high reversibility was available also for the helicity in the first large loop of the fragment, disulfide bridges of which were reduced. The fragments, which were smaller than one domain, became unstable in the SDS denaturation. The helicities of such fragments decreased in lower SDS concentrations compared with those of the intact BSA and the large fragments, which contained one or more domains. A resistance to the SDS denaturation appeared in the helices of every large loop even after the fragmentation. On the other hand, helicities of the fragments decreased to 20–25% upon the reduction of disulfide bridges. However, the helicities of these fragments increased to 35–40% in the SDS denaturation. 相似文献
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