The plant material used in the study was rice line 162d, a new small grain dwarf mutant. Polymorphic analysis of 221 SSR loci demonstrated that 162d derived from a semidwarf variety Shuhui 162 through mutation, and 16...The plant material used in the study was rice line 162d, a new small grain dwarf mutant. Polymorphic analysis of 221 SSR loci demonstrated that 162d derived from a semidwarf variety Shuhui 162 through mutation, and 162d and Shuhui 162 were just a pair of near isogenic lines. Genetic analysis of F_1 and F_2 populations suggested that dwarfism in 162d was controlled by a single recessive gene. Phenotypic characteristics of the mutant gene were that plant height was about a quarter of normal height, grain size about a quarter of normal size, leaf was short and broad, and seed setting rate was very low, compared with the near isogenic line Shuhui 162. The mutant gene was sensitive to gibberellin (GA_3) treatment and did not located on the region near the centromere of rice chromosome 5, where dl gene located. Therefore, it was concluded that the mutant gene of 162d was a new small grain dwarf gene in rice.展开更多
Six pairs of tall and dwarf near-isogenic lines derived from a dominant semi-dwarf mutant （Y98149） were selected to study height expression and sensitivity to gibberellic acid （GA3）. The lengths of the 4-5th inter...Six pairs of tall and dwarf near-isogenic lines derived from a dominant semi-dwarf mutant （Y98149） were selected to study height expression and sensitivity to gibberellic acid （GA3）. The lengths of the 4-5th internode, the 3rd, 2nd, 1st internodes from the top and the panicle length in the six dwarf near isogenic lines were 97.2%, 53.3%, 65.1%, 61.9% and 94.7% of those in the six tall ones, respectively, indicating that the dominant semi-dwarfing gene significantly inhibited the internode elongation. Moreover, Y98149 （mutant type） was more sensitive to GA3 than Y98148 （wild type）, and had a lower GA3 concentration in plant, about 78% of Y98148.展开更多
Understanding the effects of wheat dwarfing genes on the coleoptile length and plant height is crucial for the proper utilization of dwarfing genes in the improvement of wheat yield. Molecular marker analysis combined...Understanding the effects of wheat dwarfing genes on the coleoptile length and plant height is crucial for the proper utilization of dwarfing genes in the improvement of wheat yield. Molecular marker analysis combined with pedigree information were used to classify wheat cultivars widely planted in major wheat growing regions in China into different categories based on the dwarfing genes they carried. The effects of the dwarfing genes with different sensitivity to gibberellins （GA3） on the coleoptile length and plant height were analyzed. Screening of 129 cultivars by molecular marker analysis revealed that 58 genotypes of wheat contained the dwarfing gene Rht-B1b, 24 genotypes of wheat contained Rht-D1b gene and 73 genotypes of wheat possessed Rht8 gene. In addition, among these 129 cultivars, 35 genotypes of wheat cultivars contained both Rht-B1b and Rht8 genes and 16 genotypes of wheat cultivars contained both Rht-D1b and Rht8 genes. Wheat cultivars with the dwarfing genes Rht-B1b or Rht-D1b were insensitive to GA3, while the cultivars with the dwarfing gene Rht8 were sensitive to GA3. Most of the wheat genotypes containing combination of Rht8 gene with either Rht-B1b or Rht-D1b gene were insensitive to GA3. The plant height was reduced by 24.6, 30.4, 28.2, and 32.2%, respectively, for the wheat cultivars containing Rht-B1b, Rht-D1b, Rht-B1b ＋ Rht8, and Rht-D1b ＋ Rht8 genes. The plant height was reduced by 14.3% for the wheat cultivar containing GA3-sensitive gene Rht8. The coleoptile length was shortened by 25.4, 31.3, 28.4 and 31.3%, respectively, in the wheat cultivars containing Rht-B1b, Rht-D1b, Rht-B1b ＋Rht8 and Rht-D1b ＋ Rht8 genes, while the coleoptile length was shortened only by 6.2% for the wheat cultivar containing Rht8 gene. We conclude that GA3-insensitive dwarfing genes （Rht-B1b and Rht-D1b） are not suitable for the wheat improvement in dryland because these two genes have effect on reducing both plant height and coleoptile length. In contrast, GA3- sensitive dwarfing gene （Rht8） is a relatively ideal candidate for the wheat improvement since it significantly reduces the plant height of wheat, but has less effect on the coleoptile length.展开更多
The value of different dwarfing genes in winter wheat breeding was studied using 6 near-isogenic lines carrying different Rht dwarfing genes over three years experiment.Results showed that both the Rht1 and Rht2 semi-...The value of different dwarfing genes in winter wheat breeding was studied using 6 near-isogenic lines carrying different Rht dwarfing genes over three years experiment.Results showed that both the Rht1 and Rht2 semi-dwarfing genes had significantlypositive effects on kernel number and grain weight per spike, and had significantlynegative effects on 1000-grain weight comparing to the tall line(rht) and the Rht3 line.The Rht3 dwarfing gene had a significantly negative effect on kernel number per spike,and had positive effect on 1000-grain weight. The combination of the Rht2 and Rht3 geneshowed significantly negative effect on yield components. All of these 5 dwarfing orsemidwarfing genotypes mentioned above had a significantly negative effect on plantheight and no significant effect on the area of flag leaf, spikelets per spike and spikelength.展开更多
Application and functional study of dwarf and semi-dwarf genes are of great importance to both crop breeding and molecular biology. A new semi-dwarf gene, sd-t(t), non-allelic to sd-1,had been identified in an indica ...Application and functional study of dwarf and semi-dwarf genes are of great importance to both crop breeding and molecular biology. A new semi-dwarf gene, sd-t(t), non-allelic to sd-1,had been identified in an indica rice variety, Aitaiyin 2. In this study the gene was genetically mapped by using an F2 population, which consisted of 474 individuals developed from a cross between Aitaiyin 2 and B30. The sd-t(t) gene was located between the RFLP markers R514 and R1408B with a distance of 1.1 cM to R514, and 4.5 cM to R1408B on chromosome 4. A physical contig covering the sd-t(t) mapping region was further constructed by screening a BAC library with R514 and R1408B as probes, and the physical distance between R514 and R1408B was estimated at approximately 147 kb. This result will facilitate map-based cloning of the sd-t(t) gene.展开更多
Inheritance of plant height was studied in the two dwarfing gene donors, Zhepi 1 and Aizao 3, in barley breeding in China. Using direct cross and para-back-cross methods, allelic tests were carried out not only betwee...Inheritance of plant height was studied in the two dwarfing gene donors, Zhepi 1 and Aizao 3, in barley breeding in China. Using direct cross and para-back-cross methods, allelic tests were carried out not only between the dwarfing genes in Zhepi 1 and Aizao 3, but also with br, uzu, denso, or sdwl and the six novel dwarfing genes that have been recently identified in barley in China. The results showed that the plant height was attributed to Mendelian inheritance of a recessive dwarfing gene both in Zhepi 1 and Aizao 3. The dwarfing genes carried by the two cultivars were the same, but different from the three known and the six novel dwarfing genes. On the basis of the present study, only two dwarfing genes have been used in barley breeding in China since 1950.展开更多
A segregating population with 410 F2 individuals from the cross MERCIA （Rht-Bla）×Dwarf 123 was made to identify a new major dwarfing gene carrying by novel wheat germplasm Dwarf 123. Combination of bulk segeran...A segregating population with 410 F2 individuals from the cross MERCIA （Rht-Bla）×Dwarf 123 was made to identify a new major dwarfing gene carrying by novel wheat germplasm Dwarf 123. Combination of bulk segerant analysis method was used. A total of 145 SSR markers were tested for polymorphisms among parental lines and DNA bulks of F2 population. Out of 145 primer pairs only three markers revealed corresponding polymorphism among parental lines and F2 DNA bulks. The marker Barc20 was close to the dwarfing gene with a genetic distance of 1.8 cM, and markers Gwm513 and Gwm495 were linked to the gene with genetic distance of 6.7 and 13 cM, respectively. Linkage analysis mapped the dwarfing gene to the long arm of chromosome 4B with the order of Barc20-dwarfing gene-Gwm513-Gwm495. The Comparision between the new gene and the known Rht-B1 alleles showed that dwarfing gene Rht-Ai123 was different from the others. The identification of the new dwarfing gene and its linked markers will greatly facilitate its utilization in wheat high yield breeding for reducing plant height.展开更多
A novel rice d1 mutant was identified using map-based cloning and comparative analysis of known dl mutants.The mutant[d1-a) shows a mild dwarf trait,which differs only slightly from the wildtype in plant height at the...A novel rice d1 mutant was identified using map-based cloning and comparative analysis of known dl mutants.The mutant[d1-a) shows a mild dwarf trait,which differs only slightly from the wildtype in plant height at the tillering stage.The dl-a mutant is different from other dl mutants.We found that it was interrupted by an Osr4 long terminal repeat(LTR)-retrotransposon,which resulted in the loss of exon 7 in the mutant D1 mRNA.A paralog of the D1 gene.D1-like,was revealed.D1-like is a truncated gene that might have resulted from recombination between retrotransposons.We identified 65 Osr4LTR-retrotransposons in Nipponbare,and found more LTR variants in contrast to coding DNA sequence(CDS) in the retrotransposons.We also identified five possible regulatory motifs in LTRs which may control the expression of the retrotransposons.In addition,we predicted six putative functional Osr4 retrotransposons that contain complete CDSs and all important elements.Osr4 retrotransposons were classified into 4 groups,and this type of retrotransposon only appears to be present in monocots.Members of group 1-1,which included all putative functional retrotransposons,showed a high similarity with each other.The retrotransposons were expressed in all tissues,at especially higher levels in some leaves and seeds.These findings imply that transpositions of group 1-1 members might have occurred frequently and recently.展开更多
A spontaneous mutation, tentatively named d63, was derived from the twin-seedling progenies of rice crossed by diploid SARIII and Minghui 63. Compared with wild-type plants, the d63 mutant showed multiple abnormal phe...A spontaneous mutation, tentatively named d63, was derived from the twin-seedling progenies of rice crossed by diploid SARIII and Minghui 63. Compared with wild-type plants, the d63 mutant showed multiple abnormal phenotypes, such as dwarfism, more tillers, smaller flag leaf and reduced seed-setting rate and 1000-grain weight. In this study, two F2 populations were developed by crossing between d63 and Nipponbare, d63 and 93-11. Genetic analysis indicated that d63 was controlled by a single recessive gene, which was located on the short arm of chromosome 8, within the genetic distance of 0.40 cM from RM22195. Hence, D63 might be a new gene as there are no dwarf genes reported on the short arm of chromosome 8.展开更多
Expression profiles of ten pathogenesis-related （PR） genes during plant defense against Fusarium, Yellow dwarf virus （YDV） aphid-transmitted and Hessian fly （Hf） were compared temporally in both resistant and su...Expression profiles of ten pathogenesis-related （PR） genes during plant defense against Fusarium, Yellow dwarf virus （YDV） aphid-transmitted and Hessian fly （Hf） were compared temporally in both resistant and susceptible genotypes following pathogen infection or insect infestation. Quantitative real-time PCR （qRT-PCR） revealed that PR1, PR2, PR3, PR5, PR6, PR8, PR9, and PR15 appeared to be induced or suppressed independently in response to Fusarium, YDV aphid-transmitted or Hf during the interactions. The PR gene（s） essential to defense against one organism may play little or no role in defense against another pathogen or pest, suggesting the alternative mechanisms may be involved in different interactions of wheat- Fusarium, wheat-YDV aphid-transmitted and wheat-Hf. However, strong up- or down-regulation of PRl2 and PR14 encoding low molecular membrane acting protein, defensin and lipid transfer protein （LTP）, respectively, had been detected after either pathogen infection or insect infestation, therefore showed broad responses to pathogens and insects. It was postulated that low molecular proteins such as defensins and LTPs might play a role in the early stages of pathogenesis in the signaling process that informs plants about the attack from biotic stresses. In addition, a synergistic action between different PR genes might exist in plants to defense certain pathogens and insects on the basis of comprehensive expression profiling of various pathogenesis-related genes revealed by qRT-PCR in this study.展开更多
Wheat dwarf virus （WDV）, an important cereal pathogen, is closely related to Maize streak virus （MSV）, a model virus of the Mastrevirus genus. Based on its similarity to known MSV resistance strategies, a truncate...Wheat dwarf virus （WDV）, an important cereal pathogen, is closely related to Maize streak virus （MSV）, a model virus of the Mastrevirus genus. Based on its similarity to known MSV resistance strategies, a truncated part of the WDV replication- associated （RepA） gene （WDVRepA215） and the WDV RepA gene with a mutated retinoblastoma-related protein （RBR） interaction domain （WDVRepA215RBRre^t） were cloned into the plPKb002 expression vector and transformed into immature embryos of spring barley cv. Golden Promise plants through Agrobacterium-mediated transformation. A detailed study of T1-generation plants infected by leafhoppers （Psammotettix alienus） fed on infection sources of variable strength was performed over a 5-week period encompassing the initial stages of virus infection. A DNA WDV TaqMan qPCR assay normalized using the DNA puroindoline-b SYBR Green qPCR assay for samples on a per week basis revealed an approximately 2-week delay in WDVRepA215RBR^mut plants to WDVRepA215 plants before significant increases in the WDV viral levels occurred. Both WDVRepA215 and WDVRepA215RBR^mut plants showed similar levels of transgenic transcripts over the screened period; however, the transgenic plants also showed increased numbers of infected plants compared to the control plants.展开更多
Brassinosteroids （BRs） are an important class of plant steroidal hormones that are essential in a wide variety of physiological processes. To determine the effects of BRs on the development of cotton fibers, through...Brassinosteroids （BRs） are an important class of plant steroidal hormones that are essential in a wide variety of physiological processes. To determine the effects of BRs on the development of cotton fibers, through screening cotton fiber EST database and contigging the candidate ESTs, a key gene （GhDWF1） involved in the upstream biosynthetic pathway of BRs was cloned from developing fibers of upland cotton （Gossypium hirsutum L.） cv. Xuzhou 142. The full length of the cloned cDNA is 1 849 bp, including a 37 bp 5＇-untranslated region, an ORF of 1 692 bp, and a 120 bp 3＇-untranslated region. The cDNA encodes a polypeptide of 563 amino acid residues with a predicted molecular mass of 65 kD. The deduced amino acid sequence has high homology with the BR biosynthetic enzyme, DWARF1/DIMINUTO, from rice, maize, pea, tomato, and Arabidopsis. Furthermore, the typical conserved structures, such as the transmembrane domain, the FAD- dependent oxidase domain, and the FAD-binding site, are present in the GhDWF1 protein. The Southern blot indicated that the GhDWF1 gene is a single copy in upland cotton genome. RT-PCR analysis revealed that the highest level of GhDWF1 expression was detected in 0 DPA （day post anthesis） ovule （with fibers） while the lowest level was observed in cotyledon. The GhDWF1 gene presents high expression levels in root, young stem, and fiber, especially, at the fiber developmental stage of secondary cell wall accumulation. Moreover, the expression level was higher in ovules （with fibers） of wildtype （Xuzhou 142） than in ovules of fuzzless-lintless mutant at the same developmental stages （0 and 4 DPA）. The results suggest that the GhDWF1 gene plays a crucial role in fiber development.展开更多
The introduction of reduced height （Rht） genes Rht-Blb and Rht-Dlb led to impressive increases in wheat （Triticum aestivum L.） yields during the Green Revolution. In the present study, the dynamic elongation of pe...The introduction of reduced height （Rht） genes Rht-Blb and Rht-Dlb led to impressive increases in wheat （Triticum aestivum L.） yields during the Green Revolution. In the present study, the dynamic elongation of peduncle in a set ofnear-isogenic lines （NILs） carrying different Rht alleles （Rht-Blb, Rht-Dlb, Rht-Blc, Rht-Dlb＋Rht-Blb, and Rht-Dlb＋Rht-Blc） were investigated. The reduction of the final length of peduncle in NILs was dependent mainly on the elongation rate, which was reduced by Rht genes, during rapid elongation phase. Resin sections showed that Rht genes strongly reduced the cell extension in peduncle. The expression of expansin genes, which mediate cell wall loosening and leading to cell expansion, were analysed by using real- time quantitative PCR （qPCR）. Among the 23 possible wheat expansin genes, 17 were expressed in the peduncle. The spatial distribution of expression was further analysed for five expansins that showed high expression levels in the peduncles of Rht lines. Compared to wild type plants, the incorporation of Rht-Dlb allele decreased about 37 and 80% of the expression levels of ExpA 7 and ExpA3 in elongation zone, respectively. The presence Rht-Blc dwarfing genes, however, produced 53% reduction in the expression level of ExpA7, and seriously decreased about 70% of ExpB9 expression. Although the expression levels of five genes exhibited variability among the lines, an expansin gene, ExpB2, showed its expression level highly associated with the cell elongation rate in peduncle of different Rht lines.展开更多
文摘The plant material used in the study was rice line 162d, a new small grain dwarf mutant. Polymorphic analysis of 221 SSR loci demonstrated that 162d derived from a semidwarf variety Shuhui 162 through mutation, and 162d and Shuhui 162 were just a pair of near isogenic lines. Genetic analysis of F_1 and F_2 populations suggested that dwarfism in 162d was controlled by a single recessive gene. Phenotypic characteristics of the mutant gene were that plant height was about a quarter of normal height, grain size about a quarter of normal size, leaf was short and broad, and seed setting rate was very low, compared with the near isogenic line Shuhui 162. The mutant gene was sensitive to gibberellin (GA_3) treatment and did not located on the region near the centromere of rice chromosome 5, where dl gene located. Therefore, it was concluded that the mutant gene of 162d was a new small grain dwarf gene in rice.
基金This work was supported by the grants of National Natural Science Foundation of China(No.3037863)Natural Science Foundation of Anhui Province,China(No.01041103).
文摘Six pairs of tall and dwarf near-isogenic lines derived from a dominant semi-dwarf mutant （Y98149） were selected to study height expression and sensitivity to gibberellic acid （GA3）. The lengths of the 4-5th internode, the 3rd, 2nd, 1st internodes from the top and the panicle length in the six dwarf near isogenic lines were 97.2%, 53.3%, 65.1%, 61.9% and 94.7% of those in the six tall ones, respectively, indicating that the dominant semi-dwarfing gene significantly inhibited the internode elongation. Moreover, Y98149 （mutant type） was more sensitive to GA3 than Y98148 （wild type）, and had a lower GA3 concentration in plant, about 78% of Y98148.
基金supported by the National High-Tech R&D Program of China (863 Program, 2006AA100201,2006AA100223)the National Basic Research Programof China (973 Program, 2006CB708208)+1 种基金the 111 Pro-gram of Introducing Talents of Discipline to Universi-ties of China (111-2-16)the ACIAR Program of Australia (CIM/2005/111)
文摘Understanding the effects of wheat dwarfing genes on the coleoptile length and plant height is crucial for the proper utilization of dwarfing genes in the improvement of wheat yield. Molecular marker analysis combined with pedigree information were used to classify wheat cultivars widely planted in major wheat growing regions in China into different categories based on the dwarfing genes they carried. The effects of the dwarfing genes with different sensitivity to gibberellins （GA3） on the coleoptile length and plant height were analyzed. Screening of 129 cultivars by molecular marker analysis revealed that 58 genotypes of wheat contained the dwarfing gene Rht-B1b, 24 genotypes of wheat contained Rht-D1b gene and 73 genotypes of wheat possessed Rht8 gene. In addition, among these 129 cultivars, 35 genotypes of wheat cultivars contained both Rht-B1b and Rht8 genes and 16 genotypes of wheat cultivars contained both Rht-D1b and Rht8 genes. Wheat cultivars with the dwarfing genes Rht-B1b or Rht-D1b were insensitive to GA3, while the cultivars with the dwarfing gene Rht8 were sensitive to GA3. Most of the wheat genotypes containing combination of Rht8 gene with either Rht-B1b or Rht-D1b gene were insensitive to GA3. The plant height was reduced by 24.6, 30.4, 28.2, and 32.2%, respectively, for the wheat cultivars containing Rht-B1b, Rht-D1b, Rht-B1b ＋ Rht8, and Rht-D1b ＋ Rht8 genes. The plant height was reduced by 14.3% for the wheat cultivar containing GA3-sensitive gene Rht8. The coleoptile length was shortened by 25.4, 31.3, 28.4 and 31.3%, respectively, in the wheat cultivars containing Rht-B1b, Rht-D1b, Rht-B1b ＋Rht8 and Rht-D1b ＋ Rht8 genes, while the coleoptile length was shortened only by 6.2% for the wheat cultivar containing Rht8 gene. We conclude that GA3-insensitive dwarfing genes （Rht-B1b and Rht-D1b） are not suitable for the wheat improvement in dryland because these two genes have effect on reducing both plant height and coleoptile length. In contrast, GA3- sensitive dwarfing gene （Rht8） is a relatively ideal candidate for the wheat improvement since it significantly reduces the plant height of wheat, but has less effect on the coleoptile length.
基金supported by the Provincial Natural Science Foundation of Hebei,China(396313).
文摘The value of different dwarfing genes in winter wheat breeding was studied using 6 near-isogenic lines carrying different Rht dwarfing genes over three years experiment.Results showed that both the Rht1 and Rht2 semi-dwarfing genes had significantlypositive effects on kernel number and grain weight per spike, and had significantlynegative effects on 1000-grain weight comparing to the tall line(rht) and the Rht3 line.The Rht3 dwarfing gene had a significantly negative effect on kernel number per spike,and had positive effect on 1000-grain weight. The combination of the Rht2 and Rht3 geneshowed significantly negative effect on yield components. All of these 5 dwarfing orsemidwarfing genotypes mentioned above had a significantly negative effect on plantheight and no significant effect on the area of flag leaf, spikelets per spike and spikelength.
基金This work was supported by the Chinese 973 Program (Grant Nos. G1999011606 & G1999011604).
文摘Application and functional study of dwarf and semi-dwarf genes are of great importance to both crop breeding and molecular biology. A new semi-dwarf gene, sd-t(t), non-allelic to sd-1,had been identified in an indica rice variety, Aitaiyin 2. In this study the gene was genetically mapped by using an F2 population, which consisted of 474 individuals developed from a cross between Aitaiyin 2 and B30. The sd-t(t) gene was located between the RFLP markers R514 and R1408B with a distance of 1.1 cM to R514, and 4.5 cM to R1408B on chromosome 4. A physical contig covering the sd-t(t) mapping region was further constructed by screening a BAC library with R514 and R1408B as probes, and the physical distance between R514 and R1408B was estimated at approximately 147 kb. This result will facilitate map-based cloning of the sd-t(t) gene.
基金This work was financially supported by the National Natural Science Foundation of China （30370860）.
文摘Inheritance of plant height was studied in the two dwarfing gene donors, Zhepi 1 and Aizao 3, in barley breeding in China. Using direct cross and para-back-cross methods, allelic tests were carried out not only between the dwarfing genes in Zhepi 1 and Aizao 3, but also with br, uzu, denso, or sdwl and the six novel dwarfing genes that have been recently identified in barley in China. The results showed that the plant height was attributed to Mendelian inheritance of a recessive dwarfing gene both in Zhepi 1 and Aizao 3. The dwarfing genes carried by the two cultivars were the same, but different from the three known and the six novel dwarfing genes. On the basis of the present study, only two dwarfing genes have been used in barley breeding in China since 1950.
基金supported by the Natural Science Foundation of Hebei Province,China (C200500637)the Key Technologies R&D Program of China during the 11th Five-Year Plan period (2006BAD13B02-08)the Hebei Provincial Science and Technology Underpinning Project,China (06820119D)
文摘A segregating population with 410 F2 individuals from the cross MERCIA （Rht-Bla）×Dwarf 123 was made to identify a new major dwarfing gene carrying by novel wheat germplasm Dwarf 123. Combination of bulk segerant analysis method was used. A total of 145 SSR markers were tested for polymorphisms among parental lines and DNA bulks of F2 population. Out of 145 primer pairs only three markers revealed corresponding polymorphism among parental lines and F2 DNA bulks. The marker Barc20 was close to the dwarfing gene with a genetic distance of 1.8 cM, and markers Gwm513 and Gwm495 were linked to the gene with genetic distance of 6.7 and 13 cM, respectively. Linkage analysis mapped the dwarfing gene to the long arm of chromosome 4B with the order of Barc20-dwarfing gene-Gwm513-Gwm495. The Comparision between the new gene and the known Rht-B1 alleles showed that dwarfing gene Rht-Ai123 was different from the others. The identification of the new dwarfing gene and its linked markers will greatly facilitate its utilization in wheat high yield breeding for reducing plant height.
基金supported by National and Fujian Provincial Natural Science Foundation(No.31371557 and K55NI921A)Fujian Provincial Department of Education Project(K58MLV03A)a startup fund from Fujian Agriculture and Forestry University(http://www.fafu.edu.cn/)to X.S
文摘A novel rice d1 mutant was identified using map-based cloning and comparative analysis of known dl mutants.The mutant[d1-a) shows a mild dwarf trait,which differs only slightly from the wildtype in plant height at the tillering stage.The dl-a mutant is different from other dl mutants.We found that it was interrupted by an Osr4 long terminal repeat(LTR)-retrotransposon,which resulted in the loss of exon 7 in the mutant D1 mRNA.A paralog of the D1 gene.D1-like,was revealed.D1-like is a truncated gene that might have resulted from recombination between retrotransposons.We identified 65 Osr4LTR-retrotransposons in Nipponbare,and found more LTR variants in contrast to coding DNA sequence(CDS) in the retrotransposons.We also identified five possible regulatory motifs in LTRs which may control the expression of the retrotransposons.In addition,we predicted six putative functional Osr4 retrotransposons that contain complete CDSs and all important elements.Osr4 retrotransposons were classified into 4 groups,and this type of retrotransposon only appears to be present in monocots.Members of group 1-1,which included all putative functional retrotransposons,showed a high similarity with each other.The retrotransposons were expressed in all tissues,at especially higher levels in some leaves and seeds.These findings imply that transpositions of group 1-1 members might have occurred frequently and recently.
文摘A spontaneous mutation, tentatively named d63, was derived from the twin-seedling progenies of rice crossed by diploid SARIII and Minghui 63. Compared with wild-type plants, the d63 mutant showed multiple abnormal phenotypes, such as dwarfism, more tillers, smaller flag leaf and reduced seed-setting rate and 1000-grain weight. In this study, two F2 populations were developed by crossing between d63 and Nipponbare, d63 and 93-11. Genetic analysis indicated that d63 was controlled by a single recessive gene, which was located on the short arm of chromosome 8, within the genetic distance of 0.40 cM from RM22195. Hence, D63 might be a new gene as there are no dwarf genes reported on the short arm of chromosome 8.
基金financial support by the National Basic Research Program of China (2009CB118301)the Transgenic Special Item of China (2011ZX08002-004 and 2011ZX08009-003)+1 种基金the National Natural Science Foundation of China (31071405)the National High-Tech R&D Program of China (2011AA100102 and 2012AA101105)
文摘Expression profiles of ten pathogenesis-related （PR） genes during plant defense against Fusarium, Yellow dwarf virus （YDV） aphid-transmitted and Hessian fly （Hf） were compared temporally in both resistant and susceptible genotypes following pathogen infection or insect infestation. Quantitative real-time PCR （qRT-PCR） revealed that PR1, PR2, PR3, PR5, PR6, PR8, PR9, and PR15 appeared to be induced or suppressed independently in response to Fusarium, YDV aphid-transmitted or Hf during the interactions. The PR gene（s） essential to defense against one organism may play little or no role in defense against another pathogen or pest, suggesting the alternative mechanisms may be involved in different interactions of wheat- Fusarium, wheat-YDV aphid-transmitted and wheat-Hf. However, strong up- or down-regulation of PRl2 and PR14 encoding low molecular membrane acting protein, defensin and lipid transfer protein （LTP）, respectively, had been detected after either pathogen infection or insect infestation, therefore showed broad responses to pathogens and insects. It was postulated that low molecular proteins such as defensins and LTPs might play a role in the early stages of pathogenesis in the signaling process that informs plants about the attack from biotic stresses. In addition, a synergistic action between different PR genes might exist in plants to defense certain pathogens and insects on the basis of comprehensive expression profiling of various pathogenesis-related genes revealed by qRT-PCR in this study.
基金the Czech Ministry of Education, Youth and Sports funding programme LH12161the Czech Ministry of Agriculture funding programme MZE RO0417
文摘Wheat dwarf virus （WDV）, an important cereal pathogen, is closely related to Maize streak virus （MSV）, a model virus of the Mastrevirus genus. Based on its similarity to known MSV resistance strategies, a truncated part of the WDV replication- associated （RepA） gene （WDVRepA215） and the WDV RepA gene with a mutated retinoblastoma-related protein （RBR） interaction domain （WDVRepA215RBRre^t） were cloned into the plPKb002 expression vector and transformed into immature embryos of spring barley cv. Golden Promise plants through Agrobacterium-mediated transformation. A detailed study of T1-generation plants infected by leafhoppers （Psammotettix alienus） fed on infection sources of variable strength was performed over a 5-week period encompassing the initial stages of virus infection. A DNA WDV TaqMan qPCR assay normalized using the DNA puroindoline-b SYBR Green qPCR assay for samples on a per week basis revealed an approximately 2-week delay in WDVRepA215RBR^mut plants to WDVRepA215 plants before significant increases in the WDV viral levels occurred. Both WDVRepA215 and WDVRepA215RBR^mut plants showed similar levels of transgenic transcripts over the screened period; however, the transgenic plants also showed increased numbers of infected plants compared to the control plants.
文摘Brassinosteroids （BRs） are an important class of plant steroidal hormones that are essential in a wide variety of physiological processes. To determine the effects of BRs on the development of cotton fibers, through screening cotton fiber EST database and contigging the candidate ESTs, a key gene （GhDWF1） involved in the upstream biosynthetic pathway of BRs was cloned from developing fibers of upland cotton （Gossypium hirsutum L.） cv. Xuzhou 142. The full length of the cloned cDNA is 1 849 bp, including a 37 bp 5＇-untranslated region, an ORF of 1 692 bp, and a 120 bp 3＇-untranslated region. The cDNA encodes a polypeptide of 563 amino acid residues with a predicted molecular mass of 65 kD. The deduced amino acid sequence has high homology with the BR biosynthetic enzyme, DWARF1/DIMINUTO, from rice, maize, pea, tomato, and Arabidopsis. Furthermore, the typical conserved structures, such as the transmembrane domain, the FAD- dependent oxidase domain, and the FAD-binding site, are present in the GhDWF1 protein. The Southern blot indicated that the GhDWF1 gene is a single copy in upland cotton genome. RT-PCR analysis revealed that the highest level of GhDWF1 expression was detected in 0 DPA （day post anthesis） ovule （with fibers） while the lowest level was observed in cotyledon. The GhDWF1 gene presents high expression levels in root, young stem, and fiber, especially, at the fiber developmental stage of secondary cell wall accumulation. Moreover, the expression level was higher in ovules （with fibers） of wildtype （Xuzhou 142） than in ovules of fuzzless-lintless mutant at the same developmental stages （0 and 4 DPA）. The results suggest that the GhDWF1 gene plays a crucial role in fiber development.
基金financed by the National High-Tech R&D Program of China (2011AA10A106)the Main Direction Program of Knowledge Innovation of Chinese Academy of Sciences (KSCX2-EW-N-02)+1 种基金the Promotive Research Fund for Excellent Young and Middle-Aged Scientists of Shandong Province, China (BS2013NY015)the Shandong Spark Program,China (2012XH11008)
文摘The introduction of reduced height （Rht） genes Rht-Blb and Rht-Dlb led to impressive increases in wheat （Triticum aestivum L.） yields during the Green Revolution. In the present study, the dynamic elongation of peduncle in a set ofnear-isogenic lines （NILs） carrying different Rht alleles （Rht-Blb, Rht-Dlb, Rht-Blc, Rht-Dlb＋Rht-Blb, and Rht-Dlb＋Rht-Blc） were investigated. The reduction of the final length of peduncle in NILs was dependent mainly on the elongation rate, which was reduced by Rht genes, during rapid elongation phase. Resin sections showed that Rht genes strongly reduced the cell extension in peduncle. The expression of expansin genes, which mediate cell wall loosening and leading to cell expansion, were analysed by using real- time quantitative PCR （qPCR）. Among the 23 possible wheat expansin genes, 17 were expressed in the peduncle. The spatial distribution of expression was further analysed for five expansins that showed high expression levels in the peduncles of Rht lines. Compared to wild type plants, the incorporation of Rht-Dlb allele decreased about 37 and 80% of the expression levels of ExpA 7 and ExpA3 in elongation zone, respectively. The presence Rht-Blc dwarfing genes, however, produced 53% reduction in the expression level of ExpA7, and seriously decreased about 70% of ExpB9 expression. Although the expression levels of five genes exhibited variability among the lines, an expansin gene, ExpB2, showed its expression level highly associated with the cell elongation rate in peduncle of different Rht lines.
