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1.
茎顶端分生组织在植物发育过程中的保持、转变和逆转 总被引:1,自引:0,他引:1
顶端分生组织(shoot apical meristems,SAM)为产生新的器官和组织而不断提供新的细胞,它的活性依赖于平衡分生组织细胞的增殖和器官发生之间关系的调控基因.来自不具备光合能力的顶端分生组织的细胞可形成具有光合能力的营养器官.在从营养生长到生殖发育的转变过程中,茎顶端分生组织,转变为花序分生组织,最终形成花分生组织.在进入开花决定状态以前,SAM的状态很大程度上受到环境信号和转录调控因子的影响.以模式植物拟南芥为主,对在顶端分生组织的保持和转变中复杂同时又有差异的基因调控网络进行讨论.在花和花序分生组织逆转过程中,SAM中的细胞也受到相关基因的调控,且表达方式存在明显的时空差异.因此,具有决定性的和未决定性双重特性的分生组织之间的转变和相互协调,对于器官发生和形态建成起到至关重要的作用. 相似文献
2.
The effects of NaCl on putrescine (Put) content and diamine oxidase (DAO) activity in roots of rice seedlings were examined. NaCl treatment lowered the content of Put and increased the activity of DAO in roots. Our current results indicate that Cl– is not required for NaCl-induced decline in Put content and increase in DAO activity in roots. Put content in roots of rice seedlings exposed to NaCl is possibly regulated by DAO activity. 相似文献
3.
Effects of Irradiance and Copper on the Activity of Ascorbate Oxidase in Detached Rice Leaves 总被引:1,自引:0,他引:1
The effects of copper on the activity of ascorbic acid oxidasc (AAO) in detached rice leaves under both light and dark conditions
and in etiolated rice seedlings were investigated. CuSO4 increased AAO activity in detached rice leaves in both light and darkness, however, the induction in darkness was higher
than in the light. In the absence of CuSO4, irradiance (40 μmol m-2 s-1) resulted in a higher activity of AAO in detached rice leaves than dark treatment. Both CuSO4 and CuCl2 increased AAO activity in detached rice leaves, indicating that AAO is activated by Cu. Sulfate salts of Mg, Mn, Zn and Fe
were ineffective in activating AAO in detached leaves. CuSO4 was also observed to increase AAO activity in the roots but not in shoots of etiolated rice seedlings.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
Ammonium Ion, Ethylene, and Abscisic Acid in Polyethylene Glycol-treated Rice Leaves 总被引:1,自引:0,他引:1
Polyethylene glycol (PEG)-treatment decreased chlorophyll and protein contents and increased NH4
+ content due to decreased glutamine synthetase activity in detached rice leaves. PEG-treatment also increased abscisic acid
(ABA) content and decreased ethylene production. Addition of fluridone, an inhibitor of ABA biosynthesis, reduced ABA content
in rice leaves but did not prevent chlorophyll and protein loss in rice leaves induced by PEG. Silver thiosulfate, an inhibitor
of ethylene action, was effective in preventing PEG-promoted chlorophyll and protein loss, but had no effect on PEG-induced
NH4
+ accumulation. The current results suggest that NH4
+ accumulation in rice leaves induced by PEG increases leaf sensitivity to ethylene, which in turn results in an enhancement
of chlorophyll and protein loss.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
In eukaryotic cells, the origin recognition complex (ORC) governs the initiation site of DNA replication and formation of
the prereplication complex. The isolation, characterization and tissue-specific expression of a putative ORC subunit 2 (OsORC2)
in Oryza sativa is described here. A novel cDNA fragment encoding rice ORC2 was isolated by screening the subtractive library, which had
a higher expression level in inflorescence meristem than in shoot apical meristem. The full-length cDNA of rice ORC2 was obtained
by the method of rapid amplification of cDNA ends, which contained an 1140 bp open reading frame encoding a 379 amino acid
polypeptide. Sequence alignment shows that there is a high homology between the deduced amino sequence of OsORC2 and maize
ORC2 (85%). The tissue-specific expression pattern of OsORC2 reveals that it is abundant in roots, seedling and inflorescence
meristem, while its expression level is much lower in mature leaves and shoot. 相似文献
6.
The Relation between Accumulation of Abscisic Acid and Proline in Detached Rice Leaves 总被引:4,自引:0,他引:4
The relation between abscisic acid (ABA) and proline accumulation was investigated in detached rice (Oryza sativa L.) leaves. In darkness, proline content increased about 2-, 2,5- and 6-fold after 24, 48 and 72 h. ABA content reached maximum after 48 h. In the light, proline content remained almost unchanged until 48 h and subsequently increased slightly. ABA content in the light was lower than in darkness, but the maximum was also after 48 h. During 12-h exposure to decreased air humidity, proline content gradually increased, but ABA content increased about 25-fold after 4 h and declined thereafter. Exogenous application of ABA resulted in an increase in proline content in detached rice leaves under both light and darkness. 相似文献
7.
8.
Ammonium ion accumulation in detached rice leaves treated with phosphinothricin (PPT), an inhibitior of glutamine synthetase (GS), was investigated in the light and darkness. PPT treatment increased NH4
+ content and induced toxicity in rice leaves in the light but not in darkness, suggesting the importance of light in PPT-induced NH4
+ toxicity in detached rice leaves. PPT treatment in the light resulted in a decrease of activities of the cytosolic form of GS and the chloroplastic form of GS. The photosynthetic electron transport inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea reduced NH4
+ accumulation induced by PPT in the light. In darkness, PPT-induced NH4
+ accumulation and toxicity were observed in the presence of glucose or sucrose. 相似文献
9.
Ji X Van den Ende W Van Laere A Cheng S Bennett J 《Journal of molecular evolution》2005,60(5):615-634
10.
Control of Rice Embryo Development,Shoot Apical Meristem Maintenance,and Grain Yield by a Novel Cytochrome P450 总被引:1,自引:0,他引:1
Weibing Yang Mingjun Gao Xin Yin Jiyun Liu Yonghan Xu Longjun Zeng Qun Li Shubiao Zhang Junmin Wang Xiaoming Zhang Zuhua He 《植物生理学报》2013,(6):1945-1960
Angiosperm seeds usually consist of two major parts: the embryo and the endosperm. However, the molec- ular mechanism(s) underlying embryo and endosperm development remains largely unknown, particularly in rice, the model cereal. Here, we report the identification and functional characterization of the rice GIANT EMBRYO (GE) gene. Mutation of GE resulted in a large embryo in the seed, which was caused by excessive expansion of scuteUum cells. Post-embryonic growth of ge seedling was severely inhibited due to defective shoot apical meristem (SAM) mainte- nance. Map-based cloning revealed that GE encodes a CYP78A subfamily P450 monooxygenase that is localized to the endoplasmic reticulum. GE is expressed predominantly in the scutellar epithelium, the interface region between embryo and endosperm. Overexpression of GE promoted cell proliferation and enhanced rice plant growth and grain yield, but reduced embryo size, suggesting that GE is critical for coordinating rice embryo and endosperm development. Moreover, transgenic Arabidopsis plants overexpressing AtCYP78AlO, a GE homolog, also produced bigger seeds, implying a con- served role for the CYP78A subfamily of P450s in regulating seed development. Taken together, our results indicate that GE plays critical roles in regulating embryo development and SAM maintenance. 相似文献
11.
The effects of water stress on the contents of proline, ornithine, arginine and glutamic acid in detached rice leaves were examined. In water stressed leaves, the content of proline was elevated to a content approximately 8-, 14- and 17-fold higher than in control leaves after 4, 8 and 12 h, respectively. We also observed that omithine and arginine contents were much higher under water stress than in control leaves. However, the content of glutamic acid in water stressed leaves was higher after 4 and 8 h and lower after 12 h than that in control leaves. 相似文献
12.
The effects of amino acid cysteine to culture systems of microspore-derived callus induction as well as plantlet regeneration
were studied. Isolated pollen along with anther walls of basmati cultivars, Pusa basmati 1, Basmati 370 and Basmati 386 were
cultured in a medium based on N6 salts supplemented with or without cysteine following pollen embedment in agarose. The induction and regeneration medium
with cysteine gave twice as effective androgenesis and plantlet regeneration in recalcitrant basmati rice cultivars as compared
with medium lacking cysteine. Unlike the highly responsive model systems, most of the indica cultivars responded rather poorly
in anther culture. So the study may accelerate the introgression of desirable genes into basmati rice using anther culture
as a breeding tool. Response of microspores in androgenesis, plant regeneration and albinism was genotype specific. Regeneration
of Indica rice varieties remains a limiting factor for researchers undertaking transformation experiments. 相似文献
13.
以疣粒野生稻和栽培稻02428的成熟种子为材料,对愈伤组织的诱导和继代、胚性悬浮细胞系建立、原生质体制备、再生细胞团分化及植株再生进行研究。结果表明:(1)水稻愈伤组织诱导的最佳2,4-D浓度为0.014 mmol/L;(2)胚性悬浮细胞系建立的最佳条件为AA 悬浮培养基+ 0.009 mmol/L 2,4-D ,每25 mL液体培养基加入0.4 g愈伤组织的初始接种量,7 d的继代周期;(3)原生质体制备的最佳条件为20 g/L纤维素酶+ 1 g/L果胶酶,酶解5 h,800 r/min离心5 min;(4)用荧光增白剂(VBL)细胞壁染色液可以快速、准确的检测原生质体制备及培养过程中细胞壁的变化情况。 相似文献
14.
15.
Rice ubiquitin promoters: deletion analysis and potential usefulness in plant transformation systems
Strong constitutive promoters form a cornerstone for basic and applied research using transgenic plants. GUS (beta-glucuronidase) expression levels from constructs containing RUBQ1 or RUB2 rice ubiquitin promoters were 8- to 35-fold higher in transgenic rice [Oryza sativa (L.)] plants, respectively, when compared to the 35S promoter. Deletion analysis of the 5'-upstream region of RUBQ2 revealed a putative enhancer region that produced a 2.4-fold increase in transient GUS expression. Southern blot analysis showed that three to seven copies of the GUS gene were stably inserted into R0 and R1 plants and inherited in a monogenic fashion. 相似文献
16.
Role of lipid peroxidation and antioxidative enzymes (catalase, peroxidase, superoxide dismutase, ascorbate peroxidase and glutathione reductase) in water stress-promoted senescence of detached rice leaves was investigated. The senescence was followed by measuring the decrease in protein content. Increased lipid peroxidation was closely correlated with senescence in water stressed leaves. Decrease in superoxide dismutase activity was evident 8 h after beginning of water stress. However, decreased catalase, peroxidase, and ascorbate peroxidase activity was observed only when senescence was observed. Glutathione reductase was not affected by water stress. Free radical scavengers retarded water stress-enhanced senescence. 相似文献
17.
Difference in the growth response to submergence between coleoptiles and roots of rice (Oryza sativa L.) was investigated in 9-d-old rice seedlings. The coleoptile length in the submergence condition was much greater than that in aerobic condition, whereas the root length in the submergence condition was less than that in the aerobic condition. Alcohol dehydrogenase (ADH) activity in the coleoptiles in the submergence condition was much greater than that in the aerobic condition, but ADH activity in the roots in the submergence condition increased slightly. These results suggest that the preferential ADH induction in rice seedlings may contribute to the difference in the growth response between the coleoptiles and roots under low oxygen conditions. 相似文献
18.
Robert Fjellstrom Anna M. McClung A. Robert Shank 《Molecular breeding : new strategies in plant improvement》2006,17(2):149-157
Pi-z is a disease resistance gene that has been effectively used to combat a broad-spectrum of races of the rice blast fungus
Magnaporthe grisea. Although DNA markers have been reported for selection of the Pi2(t) and Pi-z resistance genes at the Pi-z locus, markers that are more tightly linked to the Pi-z locus would benefit rapid and effective cultivar development. Analysis of the publicly available genome sequence of Nipponbare
near the Pi-z locus revealed numerous SSRs that could be converted into markers. Three SSRs on rice PAC AP005659 were found to be very
tightly linked to the Pi-z locus, with one marker, AP5659-3, co-segregating with the Pi-z resistance reaction. The Pi-z factor conferring resistance to two races of blast was mapped to a 57 kb region on the physical map of Nipponbare in a location
where the Pi2(t) gene was physically mapped. Two SSR marker haplotypes were unique for cultivars carrying the Pi-z gene, which indicates these markers are useful for selection of resistance genes at the Pi-z locus in rice germplasm. 相似文献
19.
内源抗坏血酸对水稻种子萌发及幼苗生长的影响 总被引:1,自引:0,他引:1
为了解内源抗环血酸在水稻(Oryza sativa)种子中的作用,以野生型品种‘中花11’(ZH-11)、抗坏血酸合成关键酶GLDH基因的上调(超表达)株系GO-2及下调(干涉)株系GI-2为材料,研究了抗环血酸含量对其种子萌发和幼苗生长的影响。结果表明,GO-2株系的种子萌发率比野生型ZH-11高6%,比干涉型GI-2高60%。外源添加1 mmol L–1抗坏血酸后,干涉型GI-2萌发率提高了22%,GO-2及ZH-11则没有明显增加。GO-2株系在幼苗的根长、株高、分蘖数和鲜重等指标上均高于ZH-11和GI-2。实时荧光定量测定结果表明,GO-2株系叶片的GLDH基因表达量显著上调,而GI-2株系则显著下调。这说明抗坏血酸有助于维持水稻种子活力和促进水稻种子发芽和幼苗生长。 相似文献
20.
Activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) in heated crude extracts from seedlings of the rice cultivars
Hitomebore and IR28 was investigated in the presence of proline and betaine. Both solutes retarded the inactivation of the
enzyme extracted from the leaves of both cultivars at temperature-stress from 35 to 45 °C. At 50 °C, however, betaine was
effective in both cultivars. Stabilization of RuBPCO activity was independent of the added solute from 1 to 2 M concentration.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献