共查询到20条相似文献,搜索用时 453 毫秒
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Sun Ha Kim Hyun Sook Lee Won Yong Song Kwan Sam Choi Yoonkang Hur 《Journal of Plant Biology》2007,50(1):1-7
Metallothioneins (MTs) are low-molecular-weight, cysteine-rich proteins that bind to heavy metals. Type-1 MTs function under
various abiotic stresses, including exposure to the cadmium ion. We have now isolated theBrassica rapa type-1 metallothioneirt gene (BrMT1)using yeast systems, and have found that it confers resistance to Cd in otherwise Cd-sensitive yeast. Using a constitutive CaMV35S
promoter and an RbsS transit peptide, we successfully targeted BrMT1 to the chloroplastsof Arabidopsis. Overexpression in either the chloroplasts or the cytosol effectively detoxified cadmium and H2O2 stresses in transgenicArabidopsis. in particular, the chloropfast-targeted BrMTl was associated with a significant reduction in paraquat-induced chlorosis and
the accumulation of H2O2. This is the first report regarding the effects of type-1 MT1 targeted to chloroplasts. Our results suggest that this may
be applicable to the development of plants with enhanced tolerance against environmental stresses. 相似文献
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植物病程相关(PR)基因一般在病原物侵染过程中受诱导发生转录上调.目前有证据提示植物PR基因在非生物逆境胁迫下也发生转录变化,但其蛋白质的表达变化情况还鲜有报道.为了解水稻PR蛋白质在逆境胁迫下的表达特征,本文采用免疫印迹技术(Western blotting,WB)调查了8个PR蛋白质在冷、热、旱、淹和盐等5种胁迫下的表达谱.结果表明:在冷胁迫下PR8表达上调,在热胁迫下PR1a、PR3、PR5和PR16表达下调;在旱胁迫下PR1a、PR2和PR8表达上调,而PR5 和PR16表达下调,在淹胁迫下PR1、PR2和PR15表达上调,PR1a、PR3、PR5和PR8表达下调;在盐胁迫下PR2和PR3表达上调,而PR1a、PR5、PR8和PR16表达下调.另外,对这些PR 基因的上游启动子区进行分析,发现存在与胁迫响应相关的调控元件,其中脱落酸反应元件(ABRE)、TC-rich repeats和HSE的出现频率较高.这些蛋白质表达数据进一步佐证了PR蛋白在逆境胁迫反应中发挥着重要且不尽相同的作用. 相似文献
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K. B. McIntosh J. L. Hulm L. W. Young P. C. Bonham-Smith 《Plant Molecular Biology Reporter》2004,22(1):53-61
Stable transformation ofArabidopsis thaliana is a lengthy process that involves up to 3 mo of plant growth and seed selection. We have developed a rapid, 3-wk transient
assay system to test the functionality ofcis-regulatory regions controlling expression of a reporter gene in plants before undertaking stable transformation. Two-week-oldArabidopsis seedlings were vacuum-infiltrated withAgrobacterium tumefaciens cultures carrying various upstream regulatory regions controllinguidA (β-glucuronidase [GUS]) expression. Seedlings were fixed and stained for GUS activity 3–5 d following infiltration. Regulatory
regions tested in this system include the cauliflower mosaic virus (CaMV)35S promoter, the upstream regulatory region of ribosomal protein geneL23A-1, and a temperature-inducible regulatory region (HSP101B) also fromArabidopsis. The percentage of seedlings positive for GUS activity varied depending on the construct used, with the CaMV35S promoter producing the highest number of GUS-positive seedlings. Temperature induction treatments elicited increased GUS
expression in seedlings transformed with theHSP101B regulatory region. Regardless of construct, GUS expression levels were higher in seedlings collected 5 d followingAgrobacterium infiltration than those collected 3–4 d postinfiltration. 相似文献
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In this study, the expression patterns of four ferritin genes (PpFer1, PpFer2, PpFer3, and PpFer4) in pear were investigated using quantitative real-time PCR. Analysis of tissue-specific expression revealed higher expression
level of these genes in leaves than in other tested tissues. These ferritin genes were differentially expressed in response
to various abiotic stresses and hormones treatments. The expression of ferritin wasn’t affected by Fe(III)-citrate treatment.
Abscisic acid significantly enhanced the expression of all four ferritin genes, especially PpFer2, followed by N-benzylyminopurine, gibberellic acid, and indole-3-acetic acid. The expression peaks of PpFer1 and PpFer3 in leaves appeared at 6, 6, and 12 h, respectively, after pear plant was exposed to oxidative stress (5 mM H2O2), salt stress (200 mM NaCl), and heat stress (40°C). A significant increase in PpFer4 expression was detected at 6 h after salt stress or heat stress. The expression of ferritin genes was not altered by cold
stress. These results suggested that ferritin genes might be functionally important in acclimation of pear to salt and oxidative
stresses. Hormone treatments had no significant effect on expression of ferritin genes compared to abiotic stresses. This
showed accumulation of ferritin genes could be operated by different transduction pathways under abiotic stresses and hormones
treatments. 相似文献
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Hassinen VH Tervahauta AI Halimaa P Plessl M Peräniemi S Schat H Aarts MG Servomaa K Kärenlampi SO 《Planta》2007,225(4):977-989
Several populations with different metal tolerance, uptake and root-to-shoot transport are known for the metal hyperaccumulator
plant Thlaspi caerulescens. In this study, genes differentially expressed under various Zn exposures were identified from the shoots of two T. caerulescens accessions (calaminous and non-calaminous) using fluorescent differential display RT-PCR. cDNA fragments from 16 Zn-responsive
genes, including those encoding metallothionein (MT) type 2 and type 3, MRP-like transporter, pectin methylesterase (PME)
and Ole e 1-like gene as well as several unknown genes, were eventually isolated. The full-length MT2 and MT3 sequences differ from those previously isolated from other Thlaspi accessions, possibly representing new alleles or isoforms. Besides the differential expression in Zn exposures, the gene
expression was dependent on the accession. Thlaspi homologues of ClpP protease and MRP transporter were induced at high Zn concentrations. MT2 and PME were expressed at higher
levels in the calaminous accession. The MTs and MRP transporter expressed in transgenic yeasts were capable of conferring
Cu and Cd tolerance, whereas the Ole e 1-like gene enhanced toxicity to these metals. The MTs increased yeast intracellular
Cd content. As no significant differences were found between Arabidopsis and Thlaspi MTs, they apparently do not differ in their capacity to bind metals. However, the higher levels of MT2 in the calaminous
accession may contribute to the Zn-adapted phenotype. 相似文献
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Xiao-Hong Guo Jing Jiang Bai-Chen Wang Hui-Yu Li Yu-Cheng Wang Chuan-Ping Yang Gui-Feng Liu 《Molecular biology reports》2010,37(3):1183-1190
The ThPOD1 gene encodes a peroxidase and was isolated from a Tamarix hispida NaCl-stress root cDNA library. We found that ThPOD1 expression could be induced by abiotic stresses such as cold, salt, drought and exogenous abscisic acid. These findings suggested
that ThPOD1 might be involved in the plant response to environmental stresses and ABA treatment. To elucidate the function of this gene,
recombinant plasmids expressing full-length ThPOD1 as well as ThPOD2 (aa 41-337), and ThPOD3 (aa 73-337) truncated polypeptides were constructed. SDS–PAGE and Western blot analyses of the fusion proteins revealed that
the molecular weights of ThPOD1, ThPOD2 and ThPOD3 were ~57, ~50 and ~47 kDa, respectively. Stress assays of E. coli treated with the recombinant plasmids indicated that ThPOD3 could improve resistance to drought stress. This finding could
potentially be used to improve plant tolerance to drought stress via gene transfer. 相似文献
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植物特异性转录因子NAM家族从属于NAC转录因子超家族,在植株生长发育、生理代谢以及应对各种胁迫反应中均发挥重要作用。该研究采用生物信息学方法鉴定水稻基因组中的NAM基因,分析其时空表达模式、亚细胞定位以及蛋白相互作用,并采用实时定量qRT PCR方法分析不同外源激素(如SA、ABA和MeJA)以及非生物胁迫(包括干旱、盐和冷)处理下各NAM基因的表达特征,为进一步探索NAM基因在非生物胁迫中的功能和应激机制以及激素调控途径奠定基础。结果显示:(1)从水稻基因组中共鉴定出48个NAM基因,进化分析将其分为5个亚家族;NAM基因在水稻基因组中存在9对片段复制事件。(2)组织表达分析显示,NAM基因在水稻不同组织及发育时期表现特异性表达,特别是叶鞘、茎和节的生长过程中高表达,且大多数是核定位,并存在多种蛋白互作。(3)实时定量qRT PCR表达分析显示,10个NAM基因在不同组织中均特异表达;大部分NAM基因在盐和干旱胁迫下表达上调,而在冷胁迫下表达降低;SA、ABA和MeJA处理均可显著改变各NAM基因的表达水平。研究表明,NAM基因在水稻生长发育、激素应答和非生物胁迫响应中具有重要作用。 相似文献
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Ken-ichiro Tatematsu Isao Kobayashi Keiro Uchino Hideki Sezutsu Tetsuya Iizuka Naoyuki Yonemura Toshiki Tamura 《Transgenic research》2010,19(3):473-487
To construct an efficient system for the production of recombinant proteins in silkworm (Bombyx mori), we investigated the promoter activity of the silkworm sericin 1, 2, and 3 genes (Ser1, Ser2, and Ser3) using a GAL4/UAS binary gene expression system in transgenic silkworm. The promoter activity of the upstream region of Ser1 was strong, yielding high expression of an enhanced green fluorescent protein (EGFP) transgene in the middle and posterior
regions of the middle silk gland (MSG) after day 2 of the fifth instar. The Ser3 upstream region exhibited moderate promoter activity in the anterior MSG, but the Ser2 upstream region did not exhibit any promoter activity. Since the strongest promoter activity was observed for Ser1, we devised a system for the production of recombinant proteins using a GAL4–Ser1 promoter construct (Ser1-GAL4). Transgenic silkworms harboring both the Ser1-GAL4 construct and the previously reported upstream
activating sequence (UAS)–EGFP construct, which contains the TATA box region of the Drosophila
hsp70 gene, yielded approximately 100 μg EGFP per larva. When we then analyzed the TATA box region, signal peptide, and intron
sequences for their effects on production from the UAS-EGFP construct, we found that the optimization of these sequences effectively
increased production to an average of 500 μg EGFP protein per transgenic larva. We conclude that this binary system is a useful
tool for the mass production of recombinant proteins of biomedical and pharmaceutical interest in silkworm. 相似文献
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Xue-Feng Wu Chun-Lian Wang En-Bei Xie Ying Gao Ying-Lun Fan Pi-Qing Liu Kai-Jun Zhao 《Planta》2009,229(6):1231-1242
We have previously isolated a Brassica juncea cDNA encoding a novel chitinase BjCHI1 with two chitin-binding domains (Zhao and Chye in Plant Mol Biol 40:1009–1018, 1999). The expression of BjCHI1 was highly inducible by methyl jasmonate (MeJA) treatment, wounding, caterpillar feeding, and pathogenic fungal infection.
These observations suggest that the promoter of BjCHI1 gene might contain specific cis-acting elements for stress responses. Here, we report the cloning and characterization of the BjCHI1 promoter. A 1,098 bp BjCHI1 genomic DNA fragment upstream of the ATG start codon was isolated by PCR walking and various constructs were made by fusing
the BjCHI1 promoter or its derivatives to β-glucuronidase reporter gene. The transgenic Arabidopsis plants showed that the BjCHI1 promoter responded to wounding and MeJA treatment, and to treatments with either NaCl or polyethyleneglycol (PEG 6000), indicating
that the BjCHI1 promoter responses to both biotic and abiotic stresses. A transient gene expression system of Nicotiana benthamiana leaves was adopted for promoter deletion analysis, and the results showed that a 76 bp region from −695 to −620 in the BjCHI1 promoter was necessary for MeJA-responsive expression. Furthermore, removal of a conserved T/G-box (AACGTG) at −353 to −348
of the promoter greatly reduced the induction by MeJA. This is the first T/G-box element identified in a chitinase gene promoter.
Gain-of-function analysis demonstrated that the cis-acting element present in the 76 bp region requires coupling with the T/G-box to confer full magnitude of BjCHI1 induction by MeJA. 相似文献
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