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In Arabidopsis, NPR1 (non-expressor of pathogenesis related genes 1, AtNPR1) functions downstream of salicylic acid (SA) and modulates the SA mediated systemic acquired resistance. It is also involved
in a cross talk with the jasmonate pathway that is essential for resistance against herbivores and necrotrophic pathogens.
Overexpression of AtNPR1 in transgenic plants resulted in enhanced disease resistance. Recently, tobacco transgenic plants expressing AtNPR1 were shown to be tolerant to the early instars of Spodoptera litura (Meur et al., Physiol Plant 133:765–775, 2008). In this communication, we show that the heterologous expression of AtNPR1 in tobacco has also enhanced the oxidative stress tolerance. The transgenic plants exhibited enhanced tolerance to the treatment
with methyl viologen. This tolerance was associated with the constitutive upregulation of PR1, PR2 (glucanase), PR5 (thaumatin like protein), ascorbate peroxidase (APX) and Cu2+/Zn2+ superoxide dismutase (SOD). This is the first demonstration of the novel function of heterologous expression of AtNPR1 in oxidative stress tolerance in transgenic tobacco. 相似文献
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Yan F Peng J Lu Y Lin L Zheng H Chen H Chen J Adams MJ 《Molecular biology reports》2009,36(6):1283-1289
Dicer-like proteins (DCLs) are involved in small RNA-mediated development and viral defense in plants. In model plants, at
least four DCLs have been found and a number of studies have helped to understand their function. However, the function of
the Dicer or DCLs in other plants is still unclear. Here, we report the full-length cDNA sequence of Brassica rapa ssp. chinensis DCL2 (BrDCL2) gene, which contains a 4,179 bp open reading frame (ORF) encoding a protein of 1,392 amino acids. At the 3′ end of BrDCL2, clones with three different lengths of 3′ untranslated region were found. An alternative splice variant of BrDCL2, BrDCL2sv, in which one intron was retained between exon9 and exon10, was also cloned. Because of a change in the coding sequence resulting
in a premature terminal codon, BrDCL2sv was expected to translate a short peptide containing the whole DEXHc domain. 相似文献
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The promoter of the pepper pathogen-induced membrane protein gene CaPIMP1 was analyzed by an Agrobacterium-mediated transient expression assay in tobacco leaves. Several stress-related cis-acting elements (GT-1, W-box and ABRE) are located within the CaPIMP1 promoter. In tobacco leaf tissues transiently transformed with a CaPIMP1 promoter-β-glucuronidase (GUS) gene fusion, serially 5′-deleted CaPIMP1 promoters were differentially activated by Pseudomonas syringae pv. tabaci, ethylene, methyl jasmonate, abscisic acid, and nitric oxide. The −1,193 bp region of the CaPIMP1 gene promoter sequence exhibited full promoter activity. The −417- and −593 bp promoter regions were sufficient for GUS gene activation by ethylene and methyl jasmonate treatments, respectively. However, CaPIMP1 promoter sequences longer than −793 bp were required for promoter activation by abscisic acid and sodium nitroprusside treatments.
CaPIMP1 expression was activated in pepper leaves by treatment with ethylene, methyl jasmonate, abscisic acid, β-amino-n-butyric acid, NaCl, mechanical wounding, and low temperature, but not with salicylic acid. Overexpression of CaPIMP1 in Arabidopsis conferred hypersensitivity to mannitol, NaCl, and ABA during seed germination but not during seedling development. In contrast,
transgenic plants overexpressing CaPIMP1 exhibited enhanced tolerance to oxidative stress induced by methyl viologen during germination and early seedling stages.
These results suggest that CaPIMP1 expression may alter responsiveness to environmental stress, as well as to pathogen infection.
The nucleotide sequence data reported here has been deposited in the GenBank database under the accession number DQ356279. 相似文献
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The chimeras between tuber mustard (Brassica juncea) and red cabbage (B. oleracea) were artificially synthesized in our previous study. Adventitious shoots were induced from nodal segments and leaf discs
of TCC (LI-LII-LIII, LI -the outmost layer of shoot apical meristem; LII -the middle layer; LIII -the innermost layer. T = Tuber
mustard, C = Red cabbage) chimeras. The origin of the shoots was analyzed by histology and molecular biology. As a result,
the frequency of adventitious shoot induction rose with the increase of BA in MS medium in the area of the nodes. However,
there was no different induction frequency of adventitious shoots from nodal segment bases in media with different BA concentrations.
Most adventitious shoots (clustered shoots) arising from the node area were TTT (Tuber mustard- Tuber mustard- Tuber mustard)
and only 4 shoots were chimeras, which indicated that more shoots originated from LI than from LII and LIII. All shoots from
nodal segment bases were CCC (Red cabbage-Red cabbage- Red cabbage), indicating that the shoots originated from LII or LII
and LIII. There were significant differences in the regeneration rate in the margin of the leaf discs among the three combinations
of BA and NAA. Most adventitious shoots from the margin of leaf discs were CCC but 2 out of 70 were chimeras, which indicated
that more shoots originated from LII or LII and LIII than from LI. All chimeras obtained by regeneration were different from
the original explant donor in type in the present study. The origin of the adventitious shoots varied with the site of origin
on the donor plant, and could be multicellular and multihistogenic. 相似文献
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Plant aquaporins are believed to facilitate water transport across cell membranes. However, the relationship between aquaporins
and drought resistance in plants remains unclear. VfPIP1, a putative aquaporin gene, was isolated from Vicia faba leaf epidermis, and its expression was induced by abscisic acid (ABA). Our results indicated that the VfPIP1 protein was
localized in the plasma membrane, and its expression in V. faba was induced by 20% polyethylene glycol 6000. To further understand the function of VfPIP1, we obtained VfPIP1-expressing transgenic Arabidopsis thaliana plants under the control of the CaMV35S promoter. As compared to the wild-type control plants, the transgenic plants exhibited
a faster growth rate, a lower transpiration rate, and greater drought tolerance. In addition, the stomata of the transgenic
plants closed significantly faster than those of the control plants under ABA or dark treatment. These results suggest that
VfPIP1 expression may improve drought resistance of the transgenic plants by promoting stomatal closure under drought stress. 相似文献
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Tze Soo Lim Thiruvetipuram Rajam Chitra Boon Hui Tay Eng Chong Pua Hao Yu 《Journal of Plant Growth Regulation》2008,27(2):99-109
Superoxide dismutases (SODs) are ubiquitous metalloenzymes that catalyze the dismutation of superoxide radicals (O2-) to molecular oxygen (O2) and hydrogen peroxide (H2O2). In this study we characterized an Arabidopsis thaliana CuZnSOD (CSD1), a close ortholog of a previously identified Brassica juncea CuZnSOD (MSOD1). CSD1 and other two homologs CSD2 and CSD3 were spatially regulated in Arabidopsis, and CSD1 exhibited distinct expression patterns in response to different stress treatments. To investigate the in vivo function of SOD, transgenic Arabidopsis plants, expressing sense and antisense MSOD1 RNAs, were generated and those with altered SOD activity were selected for further characterization. Although SOD transgenic
plants exhibited normal phenotypes, the shoot regeneration response in transgenic explants was significantly affected by the
modulated SOD activity and the corresponding H2O2 levels. Transgenic explants with downregulated SOD activity were poorly regenerative, whereas those with upregulated SOD
activity were highly regenerative. These results suggest that shoot regeneration in vitro is regulated by the SOD activity. 相似文献
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Ni Chen Yan Liu Xin Liu Juan Chai Zhong Hu Guangqin Guo Heng Liu 《Plant Molecular Biology Reporter》2009,27(3):321-333
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Wen-bin Liao Meng-bin Ruan Bai-ming Cui Nan-fei Xu Jia-ju Lu Ming Peng 《Plant Growth Regulation》2009,58(1):35-45
The aim of the investigation reported here was to assess the role of gibberellin in cotton fiber development. The results
of experiments in which the gibberellin (GA) biosynthesis inhibitor paclobutrazol (PAC) was tested on in vitro cultured cotton
ovules revealed that GA is critical in promoting cotton fiber development. Plant responses to GA are mediated by DELLA proteins.
A cotton nucleotide with high sequence homology to Arabidopsis thaliana
GAI (AtGAI) was identified from the GenBank database and analyzed with the BLAST program. The full-length cDNA was cloned from upland
cotton (Gossypium hirsutum, Gh) and sequenced. A comparison of the putative protein sequence of this cDNA with all Arabidopsis DELLA proteins indicated that GhRGL is a putative ortholog of AtRGL. Over-expression of this cDNA in Arabidopsis plants resulted in the dwarfed phenotype, and the degrees of dwarfism were related to the expression levels of GhRGL. The deletion of 17 amino acids, including the DELLA domain, resulted in the dominant dwarf phenotype, demonstrating that
GhRGL is a functional protein that affects plant growth. Real-time quantitative PCR results showed that GhRGL mRNA is highly expressed in the cotton ovule at the elongation stage, suggesting that GhRGL may play a regulatory role in cotton fiber elongation. 相似文献
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The Perilla (Perilla frutescens L. cv. Okdong) oleosin gene, PfOle19, produces a 19-kDa protein that is highly expressed only in seeds. The activity of the −2,015 bp 5′-upstream promoter region
of this gene was investigated in transgenic Arabidopsis plants using the fusion reporter constructs of enhanced green fluorescent protein (EGFP) and β-glucuronidase (GUS). The PfOle19 promoter directs Egfp expression in developing siliques, but not in leaves, stems or roots. In the transgenic Arabidopsis, EGFP fluorescence and histochemical GUS staining were restricted to early seedlings, indehiscent siliques and mature seeds.
Progressive 5′-deletions up to the −963 bp position of the PfOle19 promoter increases the spatial control of the gene expression in seeds, but reduces its quantitative levels of expression.
Moreover, the activity of the PfOle19 promoter in mature seeds is 4- and 5-fold greater than that of the cauliflower mosaic virus 35S promoter in terms of both
EGFP intensity and fluorometric GUS activity, respectively. 相似文献
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The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae. 相似文献
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SBgLR (Solanum tuberosum genomic lysine-rich) gene was isolated from a potato genomic library using SB401 (S.
berthaultii 401) cDNA as probe. RT-PCR analysis of SBgLR gene expression profile and microscopic analysis of green fluorescent protein (GFP) expression in tobacco plants transformed
with SBgLR promoter-GFP reporters indicate that SBgLR is a pollen-specific gene. A series of 5′deletions of SBgLR promoter were fused to the β-glucuronidase (GUS) gene and stably introduced into tobacco plants. Histochemical and quantitative assays of GUS expression in transgenic
plants allowed us to localize an enhancer of SBgLR promoter to the region −345 to −269 relative to the translation start site. This 76 bp (−345 to −269) fragment enhanced GUS
expression in leaves, stems and roots when fused to −90/+6 CaMV 35S minimal promoter. Deletion analysis showed that a cis-element, which can repress gene expression in root hairs, was located in the region −345 to −311. Further study indicated
that the −269 to −9 region was sufficient to confer pollen-specific expression of GFP when fused to CaMV 35S enhancer.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Authors Zhihong Lang and Peng Zhou contributed equally to this work. 相似文献
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Beibei Huang Xiaojun Liu Xinglong Wang Yan Pi Juan Lin Jiong Fei Xiaofen Sun Kexuan Tang 《Molecular Biology》2005,39(5):684-695