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1.
Enhanced resistance to the rice blast fungus Magnaporthe grisea conferred by expression of a cecropin A gene in transgenic rice 总被引:2,自引:0,他引:2
Cecropins are a family of antimicrobial peptides, which constitute an important key component of the immune response in insects.
Here, we demonstrate that transgenic rice (Oryza sativa L.) plants expressing the cecropin A gene from the giant silk moth Hyalophora cecropia show enhanced resistance to Magnaporthe
grisea, the causal agent of the rice blast disease. Two plant codon-optimized synthetic cecropin A genes, which were designed either to retain the cecropin A peptide in the endoplasmic reticulum, the ER-CecA gene, or to secrete cecropin A to the extracellular space, the Ap-CecA gene, were prepared. Both cecropin A genes were efficiently expressed in transgenic rice. The inhibitory activity of protein extracts prepared from leaves of
cecropin A-expressing plants on the in vitro growth of M. grisea indicated that the cecropin A protein produced by the transgenic rice plants was biologically active. Whereas no effect on
plant phenotype was observed in ER-CecA plants, most of the rice lines expressing the Ap-CecA gene were non-fertile. Cecropin A rice plants exhibited resistance to rice blast at various levels. Transgene expression of cecropin A genes was not accompanied by an induction of pathogenesis-related (PR) gene expression supporting that the transgene product itself is directly active against the pathogen. Taken together, the
results presented in this study suggest that the cecropin A gene, when designed for retention of cecropin A into the endoplasmic reticulum, could be a useful candidate for protection
of rice plants against the rice blast fungus M. grisea. 相似文献
2.
Mj-AMP2, a knottin-type antimicrobial peptide, in vitro inhibits the growth of several plant pathogenic fungi including Magnaporthe oryzae. We demonstrate that transgenic rice (Oryza sativa L.) plants expressing the Mj-AMP2 gene show enhanced resistance to M. grisea, the causal agent of the rice blast disease. Mj-AMP2 was efficiently expressed and the level of Mj-AMP2 ranged from 0.32% to 0.38% of the total protein in the transgenic rice plants. In vitro inhibitory activity assays with the crude protein extract from transgenic rice indicated that the Mj-AMP2 protein produced was biologically active. Constitutive expression of Mj-AMP2 in transgenic rice reduces the growth of M. grisea by 63% with respect to untransformed control plant, and no effect on plant phenotype was observed. Transgene expression of Mj-AMP2 gene was not accompanied by an induction of pathogenesis-related (PR) gene expression indicating that the transgene product itself is directly active against the pathogen. The results presented in this study suggest that the Mj-AMP2 gene could be a useful candidate for protection of rice plants against the rice blast fungus M. grisea. 相似文献
3.
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
4.
Enhanced resistance to blast (Magnaporthe grisea) in transgenic Japonica rice by constitutive expression of rice chitinase 总被引:21,自引:0,他引:21
Y. Nishizawa Z. Nishio K. Nakazono M. Soma E. Nakajima M. Ugaki T. Hibi 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(3-4):383-390
Rice blast is the most devastating plant disease in Japan. Our goal is to create new rice varieties which show enhanced resistance
against blast, regardless of the race of blast. By an Agrobacterium-mediated transformation method, we reintroduced a rice class-I chitinase gene, Cht-2 or Cht-3, under the control of the enhanced CaMV 35S promoter and a hygromycin phosphotransferase gene, as a selection marker into
the Japonica rice varieties Nipponbare and Koshihikari, which have retained the best popularity over a long period in Japan.
In regenerated plants (R0), the Cht-2 product was found to accumulate intracellularly whereas the Cht-3 product was found to be targeted extracellularly. The transgenic rice plants which constitutively expressed either chitinase
gene showed significantly higher resistance against the rice blast pathogen Magnaporthe grisea races 007.0 and 333. Both high-level expression of the chitinase and blast-resistance were stably inherited by the next generation
in several lines.
Received: 16 November 1998 / Accepted: 30 January 1999 相似文献
5.
Finger millet plants conferring resistance to leaf blast disease have been developed by inserting a rice chitinase (chi11) gene through Agrobacterium-mediated transformation. Plasmid pHyg-Chi.11 harbouring the rice chitinase gene under the control of maize ubiquitin promoter
was introduced into finger millet using Agrobacterium strain LBA4404 (pSB1). Transformed plants were selected and regenerated on hygromycin-supplemented medium. Transient expression
of transgene was confirmed by GUS histochemical staining. The incorporation of rice chitinase gene in R0 and R1 progenies was confirmed by PCR and Southern blot analyses. Expression of chitinase gene in finger millet was confirmed by
Western blot analysis with a barley chitinase antibody. A leaf blast assay was also performed by challenging the transgenic
plants with spores of Pyricularia grisea. The frequency of transient expression was 16.3% to 19.3%. Stable frequency was 3.5% to 3.9%. Southern blot analysis confirmed
the integration of 3.1 kb chitinase gene. Western blot analysis detected the presence of 35 kDa chitinase enzyme. Chitinase
activity ranged from 19.4 to 24.8. In segregation analysis, the transgenic R1 lines produced three resistant and one sensitive for hygromycin, confirming the normal Mendelian pattern of transgene segregation.
Transgenic plants showed high level of resistance to leaf blast disease compared to control plants. This is the first study
reporting the introduction of rice chitinase gene into finger millet for leaf blast resistance. 相似文献
6.
Sharma TR Madhav MS Singh BK Shanker P Jana TK Dalal V Pandit A Singh A Gaikwad K Upreti HC Singh NK 《Molecular genetics and genomics : MGG》2005,274(6):569-578
In order to understand the molecular mechanisms involved in the gene-for-gene type of pathogen resistance, high-resolution
genetic and physical mapping of resistance loci is required to facilitate map-based cloning of resistance genes. Here, we
report the molecular mapping and cloning of a dominant gene (Pi-k
h
) present in the rice line Tetep, which is associated with resistance to rice blast disease caused by Magnaporthe grisea. This gene is effective against M. grisea populations prevalent in the Northwestern Himalayan region of India. Using 178 sequence tagged microsatellite, sequence-tagged
site, expressed sequence tag and simple sequence repeat (SSR) markers to genotype a population of 208 F2 individuals, we mapped the Pi-k
h
gene between two SSR markers (TRS26 and TRS33) which are 0.7 and 0.5 cM away, respectively, and can be used in marker-assisted-selection
for blast-resistant rice cultivars. We used the markers to identify the homologous region in the genomic sequence of Oryza sativa cv. Nipponbare, and a physical map consisting of two overlapping bacterial artificial chromosome and P1 artificial chromosome
clones was assembled, spanning a region of 143,537 bp on the long arm of chromosome 11. Using bioinformatic analyses, we then
identified a candidate blast-resistance gene in the region, and cloned the homologous sequence from Tetep. The putative Pi-k
h
gene cloned from Tetep is 1.5 kbp long with a single ORF, and belongs to the nucleotide binding site-leucine rich repeat
class of disease resistance genes. Structural and expression analysis of the Pi-k
h
gene revealed that its expression is pathogen inducible. 相似文献
7.
Rice blast, caused by the fungus Magnaporthe grisea, is a globally important disease of rice that causes annual yield losses. The segregation of genes controlling the virulence
of M. grisea on rice was studied to establish the genetic basis of cultivar specificity in the interaction of rice and M. grisea. The segregation of avirulence and virulence was studied in 87 M. grisea F1 progeny isolates from a cross of two isolates, Guy11 and JS153, using resistance-gene-differential rice cultivars. The segregation
ratio indicated that avirulence and virulence in the rice cultivars Aichi–asahi and K59, respectively, are controlled by single
major genes. Genetic analyses of backcrosses and full-sib crosses in these populations were also performed. The χ2 test of goodness-of-fitness for a 1:1 ratio indicated that one dominant gene controls avirulence in Aichi-asahi and K59 in
this population. Based on the resistance reactions of rice differential lines harboring known resistance genes to the parental
isolates, two genetically independent avirulence genes, AVR–Pit and AVR–Pia, were identified. Genetic linkage analysis showed that the SSR marker m355–356 is closely linked to AVR–Pit, on the telomere of chromosome 1 at a distance of approximately 2.3 cM. The RAPD marker S487, which was converted to a sequence-characterized
amplified region (SCAR) marker, was found to be closely linked to AVR–Pia, on the chromosome 7 telomere at a distance of 3.5 cM. These molecular markers will facilitate the positional cloning of
the two AVR genes, and can be applied to molecular-marker-assisted studies of M. grisea populations. 相似文献
8.
9.
Berruyer R Adreit H Milazzo J Gaillard S Berger A Dioh W Lebrun MH Tharreau D 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(6):1139-1147
Rice blast disease is a major constraint for rice breeding. Nevertheless, the genetic basis of resistance remains poorly understood for most rice varieties, and new resistance genes remain to be identified. We identified the resistance gene corresponding to the cloned avirulence gene ACE1 using pairs of isogenic strains of Magnaporthe grisea differing only by their ACE1 allele. This resistance gene was mapped on the short arm of rice chromosome 8 using progenies from the crosses IR64 (resistant) × Azucena (susceptible) and Azucena × Bala (resistant). The isogenic strains also permitted the detection of this resistance gene in several rice varieties, including the differential isogenic line C101LAC. Allelism tests permitted us to distinguish this gene from two other resistance genes [Pi11 and Pi-29(t)] that are present on the short arm of chromosome 8. Segregation analysis in F2 populations was in agreement with the existence of a single dominant gene, designated as Pi33. Finally, Pi33 was finely mapped between two molecular markers of the rice genetic map that are separated by a distance of 1.6 cM. Detection of Pi33 in different semi-dwarf indica varieties indicated that this gene could originate from either one or a few varieties.Communicated by D.J. Mackill 相似文献
10.
11.
Transgenic indica Rice Expressing ns-LTP-Like Protein Shows Enhanced Resistance to Both Fungal and Bacterial Pathogens 总被引:1,自引:0,他引:1
Rajesh Narhari Patkar Bharat Bhushan Chattoo 《Molecular breeding : new strategies in plant improvement》2006,17(2):159-171
Antimicrobial peptides (AMPs) from plant seeds, known to inhibit pathogen growth have a great potential in developing transgenic
plants resistant to disease. Some of the nonspecific-lipid transfer proteins (ns-LTP) that facilitate in vitro transport of lipids, show antimicrobial activity in vitro. Rice seeds also contain ns-LTPs; however, these genes are expressed weakly in seedlings. We have transformed Pusa Basmati
1, an elite indica rice cultivar, with the gene for Ace-AMP1 from Allium cepa, coding for an effective antimicrobial protein homologous to ns-LTPs. The gene for Ace-AMP1 was cloned under an inducible rice phenylalanine ammonia-lyase (PAL) or a constitutive maize ubiquitin (UbI) promoter. Ace-AMP1 was expressed in transgenic lines and secreted in the apoplastic space. Protein extracts from leaves of transgenic plants
inhibited three major rice pathogens, Magnaporthe grisea, Rhizoctonia solani and Xanthomonas oryzae, in vitro. Enhanced resistance against these pathogens was observed in in planta assays, and the degree of resistance correlating with the levels of Ace-AMP1 with an average increase in resistance to blast, sheath blight, and bacterial leaf blight disease by 86%, 67%, and 82%,
respectively. Importantly, transgenic rice plants, with stable integration and expression of Ace-AMP1, retained their agronomic characteristics while displaying enhanced resistance to both fungal and bacterial pathogens. 相似文献
12.
Sarah K. Moore Vibha Srivastava 《In vitro cellular & developmental biology. Plant》2008,44(6):468-473
The dhlA gene of Xanthobacter autotrophicus encodes dehalogenase that hydrolyzes dihaloalkanes such as 1,2-dichloroethane (DCE) into cytotoxic halogenated alcohol and
an inorganic halide. As plants do not contain dehalogenase activity, they grow normally in the presence of DCE. We tested
the transgenic expression of the bacterial dhlA gene in rice as a conditional negative selection marker. We developed 24 transgenic callus lines containing dhlA gene driven by rice actin-1 promoter, verified the expression of dhlA by Northern blot analysis, and subjected these transgenic lines to DCE treatment. We found that, while untransformed callus
(Nipponbare) was unaffected by the DCE treatment, most of the transformed lines displayed symptoms of toxicity, indicating
that dhlA is an effective conditional negative selection marker gene for rice in vitro cultures. 相似文献
13.
14.
Transfer of a grapevine stilbene synthase gene to rice (Oryza sativa L.) 总被引:17,自引:0,他引:17
P. Stark-Lorenzen B. Nelke G. Hänßler H. P. Mühlbach J. E. Thomzik 《Plant cell reports》1997,16(10):668-673
A gene derived from grapevine (Vitis vinifera) coding for stilbene synthase has been transferred into protoplasts of the commercially important japonica rice cultivar
Nipponbare using PEG-mediated direct gene transfer. Transgenic plants were regenerated from calli selected on kanamycin. Southern
blot analysis of genomic DNA isolated from regenerants and progeny plants demonstrated that the stilbene synthase gene is
stably integrated in the genome of transgenic rice plants and inherited in the offspring. The transient formation of stilbene-synthase-specific
mRNA shortly after inoculation with the fungus of the rice blast Pyricularia oryzae has demonstrated that the grapevine stilbene synthase promoter is also active in monocotyledonous plants. Preliminary results
indicate an enhanced resistance of transgenic rice to P. oryzae.
Received: 1 July 1996 / Revision received: 5 November 1996 / Accepted: 30 November 1996 相似文献
15.
A plant expression vector harboring four antifungal genes was delivered into the embryogenic calli of ‘9311’, an indica restorer
line of Super Hybrid Rice, via modified biolistic particle bombardment. Southern blot analysis indicated that in the regenerated
hygromycin-resistant plants, all the four antifungal genes, including RCH10, RAC22, β-Glu and B-RIP, were integrated into the genome of ‘9311’, co-transmitted altogether with the marker gene hpt in a Mendelian pattern. Some transgenic R1 and R2 progenies, with all transgenes displaying a normal expression level in the Northern blot analysis, showed high resistance
to Magnaporthe grisea when tested in the typical blast nurseries located in Yanxi and Sanya respectively. Furthermore, transgenic F1 plants, resulting from a cross of R2 homozygous lines with high resistance to rice blast with the non-transgenic male sterile line Peiai 64S, showed not only
high resistance to M. grisea but also enhanced resistance to rice false smut (a disease caused by Ustilaginoidea virens) and rice kernel smut (another disease caused by Tilletia barclayana). 相似文献
16.
Uchimiya Hirofumi Fujii Seiichi Huang Jirong Fushimi Takaomi Nishioka Masanori Kim Kyung-Min Yamada Maki Kawai Kurusu Takamitsu Kuchitsu Kazuyuki Tagawa Michito 《Molecular breeding : new strategies in plant improvement》2002,9(1):25-31
We isolated a rice gene (denoted YK1), which showed78 percent amino acid sequence homology to the maize HM1gene. A chimeric gene consisting of a promoter and first intron of maizeubiquitin gene and the cDNA of YK1 was introduced intorice via Agrobacterium mediated transformation. Transgenic riceplants overexpressing this chimeric gene were resistant to rice blast(Magnaporthe grisea) disease, which is one of the mostserious pathogens in rice. Furthermore, the same transgenic plants conferredhigh tolerance to several abiotic stresses such as NaCl, UV-C, submergence, andhydrogen peroxide. 相似文献
17.
Calcium-dependent protein kinases are important decoders of calcium signals in plants, which are involved in plant immunity. We report isolation and functional characterization of a pathogen-responsive OsCPK20 gene in rice. The expression of OsCPK20 in rice was significantly induced following treatment with a Magnaporthe grisea elicitor. Overexpression of constitutively active OsCPK20 in Arabidopsis enhanced the resistance to infection with Pseudomonas syringae pv. tomato, associated with elevated expression of both SA- and JA-related defense genes. Similarly, transgenic rice plants containing constitutively active OsCPK20 exhibited enhanced resistance to blast fungus M. grisea. The enhanced resistance in the transgenic Arabidopsis and rice was associated with activated expression of both SA- and JA-related defense genes. We also found that OsCPK20 was significantly induced by drought stress, indicating that OsCPK20 might be involved in plant response to drought stress. Taken together, our results indicate that rice OsCPK20 positively regulates Arabidopsis resistance against Pseudomonas syringae pv. tomato and rice resistance against M. grisea, and that it may enhance disease resistance by activating both SA- and JA-dependent defense responses. 相似文献
18.
Teppei Moriwaki Yujirou Yamamoto Takehiko Aida Tatsuya Funahashi Toshiyuki Shishido Masataka Asada Shamusul Haque Prodhan Atsushi Komamine Tsuyoshi Motohashi 《Plant biotechnology reports》2008,2(1):41-46
Salinity stress is a major limiting factor in cereal productivity. Many studies report improvements in salt tolerance using
model plants, such as Arabidopsis thaliana or standard varieties of rice, e.g., the japonica rice cultivar Nipponbare. However, there are few reports on the enhancement
of salt tolerance in local rice cultivars. In this work, we used the indica rice (Oryza sativa) cultivar BR5, which is a local cultivar in Bangladesh. To improve salt tolerance in BR5, we introduced the Escherichia coli catalase gene, katE. We integrated the katE gene into BR5 plants using an Agrobacterium tumefaciens-mediated method. The introduced katE gene was actively expressed in the transgenic BR5 rice plants, and catalase activity in T1 and T2 transgenic rice was approximately 150% higher than in nontransgenic plants. Under NaCl stress conditions, the transgenic
rice plants exhibited high tolerance compared with nontransgenic rice plants. T2 transgenic plants survived in a 200 mM NaCl solution for 2 weeks, whereas nontransgenic plants were scorched after 4 days
soaking in the same NaCl solution. Our results indicate that the katE gene can confer salt tolerance to BR5 rice plants. Enhancement of salt tolerance in a local rice cultivar, such as BR5, will
provide a powerful and useful tool for overcoming food shortage problems. 相似文献
19.
M. Srinivas Prasad B. Aruna Kanthi S. M. Balachandran M. Seshumadhav K. Madhan Mohan B. C. Viraktamath 《World journal of microbiology & biotechnology》2009,25(10):1765-1769
Samba mahsuri (BPT 5204) is a cultivar of the medium slender grain indica variety of Oryza
sativa grown across India for its high yield and quality. However, this cultivar is susceptible to several diseases and pests including
rice blast. The analysis of near isogenic lines indicated the presence of a resistance gene, Pi-1(t) in the donor cultivar C101LAC which is highly resistant to the rice blast fungus Magnaporthe grisea (M. grisea). C101LAC was crossed with susceptible indica rice cultivar (BPT 5204) to generate the mapping population. A mendelian segregation
ratio of 3:1 for resistant to susceptible F2 plants using bulk segregation analysis confirmed the presence of a major gene pi-1(t) by simple sequence repeats marker RM224 to the highly virulent blast isolate DRR 001. 相似文献
20.
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