共查询到20条相似文献,搜索用时 29 毫秒
1.
2.
3.
Regulation of Chloroplast Gene Expression is Affected in ali, a Novel Tobacco Albino Mutant 总被引:7,自引:0,他引:7
Bae Chang-Hyu; Abe Tomoko; Matsuyama Tomoki; Fukunishi Nobuhisa; Nagata Noriko; Nakano Takeshi; Kaneko Yasuko; Miyoshi Kazumitsu; Matsushima Hisashi; Yoshida Shigeo 《Annals of botany》2001,88(4):545-553
4.
The maize glyceraldehyde-3-phosphate dehydrogenase 4 (GapC4)promoter confers strong and specific anaerobic gene expressionin tobacco (Nicotiana tabacum) and potato (Solanum tuberosum).Here we show that the promoter is also anaerobically inducedin Arabidopsis thaliana. Histochemical analysis demonstratesthat the promoter is anaerobically induced in roots, leaves,stems and flower organs. Surprisingly, the strong anaerobicinduction of the promoter is dependent on light and on the substitutionof oxygen with carbon dioxide. High carbon dioxide concentrationalone does not induce the promoter in the presence of oxygenand light. If anaerobic conditions are generated under completedarkness or if plants are submerged, no induction above backgroundis observed. When transgenic tobacco harbouring a GapC4 promoterreportergene construct is analysed for light dependent anaerobic induction,the results are indistinguishable from those with arabidopsis.The implications for using the GapC4 promoter as an anaerobicreporter for monitoring alterations in the anaerobic signaltransduction pathway are discussed. 相似文献
5.
6.
Effect of Disbudding on Root Cytokinin Export and Leaf Senescence in Tomato and Tobacco 总被引:2,自引:0,他引:2
Bud removal and decapitation (disbudding) of plants of tomato(Lycopersicon esculentum Miller) and tobacco (Nicotiana tabacumL.) resulted in an increase in both the concentration and thetotal flux of cytokinin in bleeding xylem sap. There was a retardationin the rate of chlorophyll loss from leaves of disbudded plantsof both species. Ultrastructural examination of the chloroplastsof disbudded tomato plants revealed a maintenance of chloroplastintegrity, compared with chloroplasts from control plants. Itis suggested that the delaying of leaf senescence observed indisbudded plants is due to an increased availability of cytokininto these leaves. 相似文献
7.
Possible correlation between increased vigour and chitinase activity expression in tobacco 总被引:3,自引:0,他引:3
Nicotiana tabacum (tobacco) plants with severalfold increasedchitinase enzyme activity levels were obtained through transformationwith a Zea mays (maize) chitinase cDNA clone, Ch2, under thecontrol of the CaMV 35S promoter. There was a linear correlation(r=0.74, P = 0.009) between the endochitinase activity and theweight of homozygous seedlings grown in the greenhouse in someexperiments. Progeny seedlings of self-pollinated regenerants(heterozygous for Ch2) grown for 18 d in Petri plates couldbe separated into vigorous and non-vigorous categories basedon size, which were predicted to be 2n or 1,n and null, respectively,for Ch2. Testing showed that the visually estimated vigour ofthese progeny co-segregating for Ch2 and npfll generally correlatedwith resistance to kanamycin and chitinase activity. There wasalso a correlation between growth and chitinase activity insuspension cultures derived from transgenic and wild-type whenmeasured after 20 d. Twelve-day-old wild-type and transformedseedlings grown in soil under culture room conditions in closedplastic containers were visibly taller and had higher seedlingweights than their counterparts grown under mist in the greenhouse.Likewise, the chitinase activity in the cell wall-bound proteinsof the faster growing seedlings was more than double that ofthe greenhouse-grown seedlings. While these studies do not always demonstrate the correlationbetween vigour and chitinase activity, overall, they do supportthe hypothesis that chitinases have a role in plant growth. Key words: Chitinase, maize endochitinase, growth, tobacco 相似文献
8.
A 1.3-kb fragment from the 5'-flanking region of the RGS-38gene, which encodes the plastidic glutamine synthetase in Oryzasativa L., was fused to a ß-glucuronidase (GUS) reportergene and introduced into Nicotiana tabacum by Agrobacterium-mediatedtransformation. The promoter directed GUS expression, both inleaves and in roots, and the expression of GUS was regulatedby light. The GUS activity was high in the mature leaves ofthe transgenic tobacco plants, in marked contrast to the activityof the GS1 promoter. The GS2 promoter also responded to externallyapplied ammonia, as is the case for the GS1 promoter. Theseresults suggest that the cis-acting regulatory elements thatcontrol the response to ammonia, a substrate for glutamine synthetase,are located within a 1.3-kb region of the promoter. (Received October 1, 1991; Accepted January 20, 1992) 相似文献
9.
10.
11.
The Mechanical Properties of Xylem Tissue from Tobacco Plants (Nicotiana tabacum'Samsun') 总被引:1,自引:0,他引:1
Tobacco plants (Nicotiana tabacumSamsun) havebeen grown with an antisense CAD (cinnamyl alcohol dehydrogenase)gene. This modifies lignin production, resulting in lignin witha greater aldehyde content which is easier to extract chemically.This lignin probably has a reduced crosslink density. The changedproperties of the lignin affect the longitudinal tensile modulusof the xylem tissue (wood), reducing it by one third, from 2.8GPa to 1.9 GPa. Tobacco xylem tissue cell walls are more sensitiveto changes in the properties of the matrix than can be predictedusing current cell wall mechanical models.Copyright 1998 Annalsof Botany Company Tobacco,Nicotiana tabacum, xylem tissue, Young's modulus, matrix polymer connectivity, plant biomechanics. 相似文献
12.
Molecular Cloning and Expression Analysis of the Rhodobacter capsulatus sodB Gene, Encoding an Iron Superoxide Dismutase
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Nstor Cortez Nstor Carrillo Ccile Pasternak Angelika Balzer Gabriele Klug 《Journal of bacteriology》1998,180(20):5413-5420
Genetic complementation of a sodA sodB Escherichia coli mutant strain was used to clone Rhodobacter capsulatus genes involved in detoxification of superoxide radicals. After sequence analysis, 1 of the 16 identical clones obtained by this selection procedure was shown to contain an open reading frame with sequence similarity to that coding for Fe-containing superoxide dismutases (SodB). The R. capsulatus sodB gene was expressed in E. coli, and the nature of the metal ligand was confirmed by inhibitor sensitivity assays with lysates from both bacterial species. Activity staining of cleared Rhodobacter lysates resolved by polyacrylamide gel electrophoresis indicated that SodB was the only superoxide dismutase present in this phototrophic organism. The sodB gene was expressed at low levels in R. capsulatus cells grown under anaerobic or semiaerobic conditions, but expression was strongly induced upon exposure of the bacteria to air or to methyl viologen. Attempts to construct a sodB mutant in this organism by allelic exchange of the chromosomal copy of the gene with a suicide plasmid containing a mutated sodB gene were unsuccessful, strongly suggesting that the encoded superoxide dismutase is essential for viability of R. capsulatus in aerobic cultures. 相似文献
13.
14.
15.
Alekseeva V. V. Rukavtsova E. B. Bobreshova M. E. Lozhnikova V. N. Bur'yanov Ya. I. 《Russian Journal of Plant Physiology》2004,51(4):541-546
The expression of the agrobacterial iaaM gene for tryptophan monooxygenase, the enzyme catalyzing the first step in the auxin biosynthesis, induced substantial physiological and biochemical changes in transgenic tobacco (Nicotiana tabacum L.) plants. All lines of transgenic plants grown in vitro manifested abnormal phenotypes: enhanced root formation, adventitious roots on stems, and curled leaves. When grown in vivo, plants manifested abnormal, normal, or intermediate phenotype. Under conditions of a greenhouse, the abnormal plants contained the highest amount of auxins in their leaves and manifested an increased number of adventitious roots, poor reproductivity, and the loss in seed germination. Transgenic plants with the normal phenotype did not substantially differ from the wild-type plants in their morphology, and their auxin content was lower than in the abnormal plants. The intermediate-phenotype plants were devoid of some morphological properties characteristic of the abnormal plants. Only the seeds of normal- and intermediate-phenotype transgenic plants germinated at a high rate. 相似文献
16.
Chloramphenicol Acetyl Transferase (CAT) Protein Is Expressed in Transgenic Tobacco in Field Tests following Attack by Insects 总被引:3,自引:1,他引:2
下载免费PDF全文
![点击此处可从《Plant physiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The expression of chloramphenical acetyl transferase (CAT) protein driven by the wound-inducible promoter from the proteinase inhibitor II K (pin2) gene was examined in whole tobacco (Nicotiana tabacum L.) plants under field conditions. Mechanical wounding of the field-grown leaves caused an accumulation of CAT protein in these leaves which begins several hours after wounding and continues to accumulate for about 36 hours. When sections of leaves were assayed for accumulation of CAT protein following wounding, the CAT protein was found to accumulate in the apical portions of the leaves. When endogenous insects attacked the leaves of transgenic plants grown in the field, the plants responded by inducing CAT protein. The mesophyll cells of the leaf were the site of expression of the CAT protein rather than the mid-vein or major veins within the leaf blade, indicating that the wound-inducible pin2 promoter specifically directs the synthesis of novel genes in tissues preferentially consumed by larval insects. 相似文献
17.
18.
Long-distance signals generated in shoots are thought to be associated with the regulation of iron uptake from roots; however,
the signaling mechanism is still unknown. To elucidate whether the signal regulates iron uptake genes in roots positively
or negatively, we analyzed the expressions of two representative iron uptake genes: NtIRT1 and NtFRO1 in tobacco (Nicotiana tabacum L.) roots, after shoots were manipulated in vitro. When iron-deficient leaves were treated with Fe(II)-EDTA, the expressions
of both genes were significantly reduced; nevertheless iron concentration in the roots maintained a similar level to that
in roots grown under iron-deficient conditions. Next, all leaves from tobacco plants grown under the iron-deficient condition
were excised. The expression of two genes were quickly reduced below half within 2 h after the leaf excision and gradually
disappeared by the end of a 24-h period. The NtIRT1 expression was compared among the plants whose leaves were cut off in various patterns. The expression increased in proportion
to the dry weight of iron-deficient leaves, although no relation was observed between the gene expression and the position
of excised leaves. Interestingly, the NtIRT1 expression in hairy roots increased under the iron-deficient condition, suggesting that roots also have the signaling mechanism
of iron status as well as shoots. Taken together, these results indicate that the long-distance signal generated in iron-deficient
tissues including roots is a major factor in positive regulation of the expression of NtIRT1 and NtFRO1 in roots, and that the strength of the signal depends on the size of plants. 相似文献
19.
Cotton metallothionein GhMT3a, a reactive oxygen species scavenger, increased tolerance against abiotic stress in transgenic tobacco and yeast 总被引:7,自引:0,他引:7
Xue Tongtong; Li Xinzheng; Zhu Wei; Wu Changai; Yang Guodong; Zheng Chengchao 《Journal of experimental botany》2009,60(1):339-349
A cDNA clone encoding a 64-amino acid type 3 metallothioneinprotein, designated GhMT3a, was isolated from cotton (Gossypiumhirsutum) by cDNA library screening. Northern blot analysisindicated that mRNA accumulation of GhMT3a was up-regulatednot only by high salinity, drought, and low temperature stresses,but also by heavy metal ions, abscisic acid (ABA), ethylene,and reactive oxygen species (ROS) in cotton seedlings. Transgenictobacco (Nicotiana tabacum) plants overexpressing GhMT3a showedincreased tolerance against abiotic stresses compared with wild-typeplants. Interestingly, the induced expression of GhMT3a by salt,drought, and low-temperature stresses could be inhibited inthe presence of antioxidants. H2O2 levels in transgenic tobaccoplants were only half of that in wild-type (WT) plants undersuch stress conditions. According to in vitro assay, recombinantGhMT3a protein showed an ability to bind metal ions and scavengeROS. Transgenic yeast overexpressing GhMT3a also showed highertolerance against ROS stresses. Taken together, these resultsindicated that GhMT3a could function as an effective ROS scavengerand its expression could be regulated by abiotic stresses throughROS signalling. Key words: Abiotic stress, antioxidant, GhMT3a, ROS, transgenic tobacco, yeast 相似文献