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  1. Article: The Effect of Diaphragmatic Breathing on Attention, Negative Affect and Stress in Healthy Adults.

    Ma, Xiao / Yue, Zi-Qi / Gong, Zhu-Qing / Zhang, Hong / Duan, Nai-Yue / Shi, Yu-Tong / Wei, Gao-Xia / Li, You-Fa

    Frontiers in psychology

    2017  Volume 8, Page(s) 874

    Abstract: A growing number of empirical studies have revealed that diaphragmatic breathing may trigger body relaxation responses and benefit both physical and mental health. However, the specific benefits of diaphragmatic breathing on mental health remain largely ... ...

    Abstract A growing number of empirical studies have revealed that diaphragmatic breathing may trigger body relaxation responses and benefit both physical and mental health. However, the specific benefits of diaphragmatic breathing on mental health remain largely unknown. The present study aimed to investigate the effect of diaphragmatic breathing on cognition, affect, and cortisol responses to stress. Forty participants were randomly assigned to either a breathing intervention group (BIG) or a control group (CG). The BIG received intensive training for 20 sessions, implemented over 8 weeks, employing a real-time feedback device, and an average respiratory rate of 4 breaths/min, while the CG did not receive this treatment. All participants completed pre- and post-tests of sustained attention and affect. Additionally, pre-test and post-test salivary cortisol concentrations were determined in both groups. The findings suggested that the BIG showed a significant decrease in negative affect after intervention, compared to baseline. In the diaphragmatic breathing condition, there was a significant interaction effect of group by time on sustained attention, whereby the BIG showed significantly increased sustained attention after training, compared to baseline. There was a significant interaction effect of group and time in the diaphragmatic breathing condition on cortisol levels, whereby the BIG had a significantly lower cortisol level after training, while the CG showed no significant change in cortisol levels. In conclusion, diaphragmatic breathing could improve sustained attention, affect, and cortisol levels. This study provided evidence demonstrating the effect of diaphragmatic breathing, a mind-body practice, on mental function, from a health psychology approach, which has important implications for health promotion in healthy individuals.
    Language English
    Publishing date 2017-06-06
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2563826-9
    ISSN 1664-1078
    ISSN 1664-1078
    DOI 10.3389/fpsyg.2017.00874
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Tai Chi Chuan modulates heart rate variability during abdominal breathing in elderly adults.

    Wei, Gao-Xia / Li, You-Fa / Yue, Xiao-Lin / Ma, Xiao / Chang, Yu-Kai / Yi, Long-Yan / Li, Jing-Cheng / Zuo, Xi-Nian

    PsyCh journal

    2016  Volume 5, Issue 1, Page(s) 69–77

    Abstract: Tai Chi Chuan (TCC) practice is currently intentionally applied in clinical populations, especially those with cardiovascular diseases because of its potential benefits on the autonomic nervous system. The long-term effect of TCC practice on heart rate ... ...

    Abstract Tai Chi Chuan (TCC) practice is currently intentionally applied in clinical populations, especially those with cardiovascular diseases because of its potential benefits on the autonomic nervous system. The long-term effect of TCC practice on heart rate variability (HRV) remains largely unknown. In this study, we recruited 23 TCC practitioners whose experience averaged approximately 21 years and 19 controls matched by age, sex and education to examine the effect of TCC practice on the autonomic nervous system during a resting state and during an abdominal breathing state. HRV was measured by traditional electrocardiogram (ECG) recording. The results showed that the low frequency, total power frequency, and normalized low frequency components and the low-frequency/high-frequency ratio were significantly higher, whereas the normalized high frequency was significantly lower in the TCC practitioners relative to controls during the abdominal breathing state. However, we did not detect any significant difference in the HRV measures during the resting state between the two groups. Additionally, TCC experience did not correlate with HRV components either in the abdominal state or the resting state in the TCC group. Considering all of these findings, we suggest that TCC improves vagal activity and the balance between sympathetic and parasympathetic activity during the relaxation state. This study also provides direct physiological evidence for the role of TCC practice in relaxation.
    MeSH term(s) Aged ; Autonomic Nervous System/physiology ; Electrocardiography ; Female ; Heart Rate ; Humans ; Male ; Middle Aged ; Respiration ; Tai Ji
    Language English
    Publishing date 2016-03
    Publishing country Australia
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2717141-3
    ISSN 2046-0260 ; 2046-0252
    ISSN (online) 2046-0260
    ISSN 2046-0252
    DOI 10.1002/pchj.105
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: A down-regulated epi-allele of the genomes uncoupled 4 gene generates a xantha marker trait in rice.

    Li, Rui-Qing / Huang, Jian-Zhong / Zhao, Hai-Jun / Fu, Hao-Wei / Li, You-Fa / Liu, Guo-Zhen / Shu, Qing-Yao

    TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik

    2014  Volume 127, Issue 11, Page(s) 2491–2501

    Abstract: Key message: A γ-ray-induced xantha trait is epigenetically controlled by the genomes uncoupled 4 gene with enhanced promoter segment methylation and down-regulated expression in rice. For easy testing and to increase varietal purity, a xantha mutation ( ...

    Abstract Key message: A γ-ray-induced xantha trait is epigenetically controlled by the genomes uncoupled 4 gene with enhanced promoter segment methylation and down-regulated expression in rice. For easy testing and to increase varietal purity, a xantha mutation (xnt), which turns plants yellow and makes them visually distinguishable from normal green rice, has been generated and bred into male sterile lines for hybrid rice production. The xnt locus was previously fine mapped to a ~100-kb interval on chromosome 11, but its identity was unknown. In this study, xnt was further narrowed down to a 57-kb fragment carrying eight opening reading frames (ORFs). All eight ORFs had identical genomic sequences and all but ORF2 (g enomes uncoupled 4, OsGUN4) had similar transcript abundance in the xantha mutant Huangyu B (HYB) and its parental variety Longtefu B (LTB). The expression of OsGUN4, however, was significantly reduced in HYB compared with LTB in terms of both transcript abundance (0.2% that of LTB) and expressed protein level (barely detectable in HYB but greater than the heat shock protein reference in LTB). Therefore, OsGUN4 was identified as the candidate gene underlying the xantha trait. The function of OsGUN4 in the xantha phenotype was confirmed by identification and characterization of new allelic OsGUN4 mutations. Comparative bisulfite genomic sequencing of OsGUN4 revealed increased methylation in a promoter region in the mutant, and the correlation between increased methylation and the xantha phenotype was further verified by demethylation treatment. In summary, we have identified an epi-allele of OsGUN4 as the causal gene of the xantha marker trait and revealed that enhanced methylation in its promoter down-regulated its expression in rice.
    MeSH term(s) Alleles ; Carotenoids/metabolism ; Chlorophyll/metabolism ; Chromosome Mapping ; DNA Methylation ; DNA Mutational Analysis ; DNA, Plant/genetics ; Down-Regulation ; Epigenesis, Genetic ; Gamma Rays ; Gene Expression Regulation, Plant ; Genetic Markers ; Intracellular Signaling Peptides and Proteins/genetics ; Open Reading Frames ; Oryza/genetics ; Phenotype ; Plant Proteins/genetics ; Polymorphism, Single Nucleotide ; Promoter Regions, Genetic
    Chemical Substances DNA, Plant ; Genetic Markers ; Intracellular Signaling Peptides and Proteins ; Plant Proteins ; Chlorophyll (1406-65-1) ; Carotenoids (36-88-4)
    Language English
    Publishing date 2014-09-11
    Publishing country Germany
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2170-2
    ISSN 1432-2242 ; 0040-5752
    ISSN (online) 1432-2242
    ISSN 0040-5752
    DOI 10.1007/s00122-014-2393-9
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: A down-regulated epi-allele of the genomes uncoupled 4 gene generates a xantha marker trait in rice

    Li, Rui-Qing / Huang, Jian-Zhong / Zhao, Hai-Jun / Fu, Hao-Wei / Li, You-Fa / Liu, Guo-Zhen / Shu, Qing-Yao

    Theoretical and applied genetics. 2014 Nov., v. 127, no. 11

    2014  

    Abstract: KEY MESSAGE : A γ-ray-induced xantha trait is epigenetically controlled by the genomes uncoupled 4 gene with enhanced promoter segment methylation and down-regulated expression in rice. For easy testing and to increase varietal purity, a xantha mutation ( ...

    Abstract KEY MESSAGE : A γ-ray-induced xantha trait is epigenetically controlled by the genomes uncoupled 4 gene with enhanced promoter segment methylation and down-regulated expression in rice. For easy testing and to increase varietal purity, a xantha mutation (xnt), which turns plants yellow and makes them visually distinguishable from normal green rice, has been generated and bred into male sterile lines for hybrid rice production. The xnt locus was previously fine mapped to a ~100-kb interval on chromosome 11, but its identity was unknown. In this study, xnt was further narrowed down to a 57-kb fragment carrying eight opening reading frames (ORFs). All eight ORFs had identical genomic sequences and all but ORF2 (g enomes uncoupled 4, OsGUN4) had similar transcript abundance in the xantha mutant Huangyu B (HYB) and its parental variety Longtefu B (LTB). The expression of OsGUN4, however, was significantly reduced in HYB compared with LTB in terms of both transcript abundance (0.2 % that of LTB) and expressed protein level (barely detectable in HYB but greater than the heat shock protein reference in LTB). Therefore, OsGUN4 was identified as the candidate gene underlying the xantha trait. The function of OsGUN4 in the xantha phenotype was confirmed by identification and characterization of new allelic OsGUN4 mutations. Comparative bisulfite genomic sequencing of OsGUN4 revealed increased methylation in a promoter region in the mutant, and the correlation between increased methylation and the xantha phenotype was further verified by demethylation treatment. In summary, we have identified an epi-allele of OsGUN4 as the causal gene of the xantha marker trait and revealed that enhanced methylation in its promoter down-regulated its expression in rice.
    Keywords Oryza sativa ; crop production ; gene expression regulation ; genes ; heat shock proteins ; hybrids ; loci ; methylation ; mutants ; mutation ; phenotype ; promoter regions ; rice ; sequence analysis
    Language English
    Dates of publication 2014-11
    Size p. 2491-2501.
    Publishing place Springer-Verlag
    Document type Article
    ZDB-ID 2170-2
    ISSN 1432-2242 ; 0040-5752
    ISSN (online) 1432-2242
    ISSN 0040-5752
    DOI 10.1007/s00122-014-2393-9
    Database NAL-Catalogue (AGRICOLA)

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  5. Article: A revisit of mutation induction by gamma rays in rice (Oryza sativa L.): implications of microsatellite markers for quality control

    Fu, Hao-Wei / Li, You-Fa / Shu, Qing-Yao

    Molecular breeding. 2008 Sept., v. 22, no. 2

    2008  

    Abstract: Mutation techniques have been used for generating genetic variation and breeding new varieties during the past decades. However, the skepticism has also persisted during the course on the sole mutational origin of genetic variation in mutated populations. ...

    Abstract Mutation techniques have been used for generating genetic variation and breeding new varieties during the past decades. However, the skepticism has also persisted during the course on the sole mutational origin of genetic variation in mutated populations. We addressed this issue using three unique rice genetic lines in this study. First, we confirmed that gamma rays had significant effect on the growth of M₁ plants, leading to significant reduction of fertility, seed set and plant height at doses 200 Gy and above. Second, we proved that out-crossing derived genetic variants existed in M₂ population (0.8%) and among selected putative mutants (0-33.3%), in addition to induced mutants. Third, we demonstrated that true induced mutant lines had identical microsatellite haplotypes to their parents. We proposed microsatellite assay as a method to exclude any genetic contaminants from induced mutants, with appropriate numbers for different levels of power based on reported microsatellite mutation rate and microsatellite polymorphic index.
    Keywords Oryza sativa ; gamma radiation ; genetic lines ; genetic variation ; haplotypes ; microsatellite repeats ; mutants ; mutation ; outcrossing ; parents ; pollutants ; quality control ; rice ; seed set
    Language English
    Dates of publication 2008-09
    Size p. 281-288.
    Publisher Springer Netherlands
    Publishing place Dordrecht
    Document type Article
    ZDB-ID 1230924-2
    ISSN 1572-9788 ; 1380-3743
    ISSN (online) 1572-9788
    ISSN 1380-3743
    DOI 10.1007/s11032-008-9173-7
    Database NAL-Catalogue (AGRICOLA)

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  6. Article: Functional molecular markers and high-resolution melting curve analysis of low phytic acid mutations for marker-assisted selection in rice

    Tan, Yuan-Yuan / Fu, Hao-Wei / Zhao, Hai-Jun / Lu, Sha / Fu, Jun-Jie / Li, You-Fa / Cui, Hai-Rui / Shu, Qing-Yao

    Molecular breeding. 2013 Mar., v. 31, no. 3

    2013  

    Abstract: Phytic acid (PA, myo-inositol-1,2,3,4,5,6-hexakis-phosphate) and its salt form (phytate) are the principal storage forms of phosphorus in cereal grains. Since PA and phytates cannot be efficiently digested by monogastric animals, the abundance of PA in ... ...

    Abstract Phytic acid (PA, myo-inositol-1,2,3,4,5,6-hexakis-phosphate) and its salt form (phytate) are the principal storage forms of phosphorus in cereal grains. Since PA and phytates cannot be efficiently digested by monogastric animals, the abundance of PA in cereal and legume grains causes nutritional and environmental problems. The present study aimed at developing breeder-friendly functional molecular markers of five low phytic acid (LPA) mutant alleles of three rice (Oryza sativa L.) genes: viz., XQZ-lpa (a 1,475-bp deletion) and KBNT-lpa (a C→T single nucleotide polymorphism [SNP]) of LOC_Os02g57400, Z9B-lpa (a 6-bp deletion) and MH-lpa (a 1-bp deletion) of LOC_Os04g55800, and XS-lpa (a C→T SNP) of LOC_Os03g04920. First, markers for gel-based length polymorphism analysis were developed: viz., two insertion–deletion markers for XQZ-lpa and Z9B-lpa, two cleaved amplified polymorphic sequence (CAPS) markers for KBNT-lpa and XS-lpa, and one derived CAPS marker for MH-lpa. Second, the high-resolution melting (HRM) curve analysis method was explored for distinguishing plants with wild-type (WT) and LPA alleles (except XQZ-lpa). Plants of genotypes with homozygous mutant allele and WT, and with heterozygous alleles, could be directly differentiated by HRM for KBNT-lpa, XS-lpa and MH-lpa; only heterozygous individuals could be directly distinguished from homozygous WT and mutant plants for Z9B-lpa. However, by adding 15 % WT DNA templates to test samples before PCR, amplicons of three genotypes of the Z9B-lpa allele could also be differentiated by HRM analysis. Third, it was demonstrated that these markers could be effectively used for marker-assisted selection of LPA rice, and breeding lines with two non-allelic LPA mutations were developed with PA contents significantly lower than their respective parental LPA lines. Taken together, the present study developed functional molecular markers for efficient selection of LPA plants and demonstrated that double mutant LPA lines with significantly lower PA levels than primary LPA mutants (with single mutations) could be developed by pyramiding two non-allelic LPA mutations.
    Keywords DNA ; Oryza sativa ; alleles ; breeding lines ; genetic markers ; genotype ; legumes ; marker-assisted selection ; melting ; mutants ; phosphorus ; phytic acid ; polymerase chain reaction ; rice ; single nucleotide polymorphism
    Language English
    Dates of publication 2013-03
    Size p. 517-528.
    Publishing place Springer-Verlag
    Document type Article
    ZDB-ID 1230924-2
    ISSN 1572-9788 ; 1380-3743
    ISSN (online) 1572-9788
    ISSN 1380-3743
    DOI 10.1007/s11032-012-9809-5
    Database NAL-Catalogue (AGRICOLA)

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  7. Article: Generation and characterization of bentazon susceptible mutants of commercial male sterile lines and evaluation of their utility in hybrid rice production

    Wang, Qi-Zhao / Fu, Hao-Wei / Huang, Jian-Zhong / Zhao, Hai-Jun / Li, You-Fa / Zhang, Bin / Shu, Qing-Yao

    Field crops research. 2012 Oct. 20, v. 137

    2012  

    Abstract: Male sterile lines are required to have complete male sterility during hybrid seed production to ensure high seed purity in rice. However, unexpected temperature fluctuations during the reproductive stage could cause partial fertility reversion of ... ...

    Abstract Male sterile lines are required to have complete male sterility during hybrid seed production to ensure high seed purity in rice. However, unexpected temperature fluctuations during the reproductive stage could cause partial fertility reversion of certain types of male sterile rice, resulting in decreased hybrid seed purity. Herbicide susceptible male sterile lines have been sought to solve the problem through the use of herbicide spray at seedling stage of hybrid to eliminate seedlings of selfed sterile line. Two such male sterile lines, one CMS line and one P/TGMS line, which are otherwise excellent, were subjected to gamma-ray mutagenesis for bentazon susceptibility. A cost-effective system with a ∼20-fold workload reduction was first developed for bentazon susceptible mutant selection; three bentazon susceptible mutant lines were subsequently selected and identified to carry independent mutations of the CYP81A6 gene: one 1-bp deletion, one 2-bp deletion and one 11-bp deletion, which all would result in truncated and dysfunctional CYP81A6 enzymes. Two molecular markers were also developed for the latter two mutations, which are expected to facilitate the efficient use of the mutations in future breeding programs. No significant negative effects on other agronomic traits of both the mutants and their F₁ hybrids with other varieties were observed, which indicated that the mutant lines could directly replace their parental lines in commercial hybrid rice production. Herbicide test also proved that all contaminated bentazon susceptible seedlings could be completely killed while hybrid seedlings were not affected. Taking together, our study demonstrated that bentazon susceptible mutants of practical use for maintaining high hybrid rice purity in paddy fields could be developed by gamma-ray mutagenesis of commercial male sterile lines aided with an efficient selection protocol.
    Keywords agronomic traits ; bentazon ; crop production ; enzymes ; genes ; genetic markers ; hybrids ; mutagenesis ; mutants ; paddies ; problem solving ; rice ; seedlings ; seeds ; temperature
    Language English
    Dates of publication 2012-1020
    Size p. 12-18.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 435684-6
    ISSN 0378-4290
    ISSN 0378-4290
    DOI 10.1016/j.fcr.2012.09.001
    Database NAL-Catalogue (AGRICOLA)

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  8. Article: Microsatellite analysis for revealing parentage of gamma ray-induced mutants in rice (Oryza sativa L.)

    Fu, Hao Wei / Wang, Cai Xia / Shu, Xiao Li / Li, You Fa / Wu, Dian Xing / Shu, Qing Yao

    Israel journal of plant sciences

    Volume v. 55,, Issue no. 2

    Abstract: We previously demonstrated that mutants induced from pure lines with quality assurance had microsatellite (or simple sequence repeat, SSR) genotypes almost identical to their parent varieties, and genetic variants derived from accidental out-crossing ... ...

    Abstract We previously demonstrated that mutants induced from pure lines with quality assurance had microsatellite (or simple sequence repeat, SSR) genotypes almost identical to their parent varieties, and genetic variants derived from accidental out-crossing might be selected as "mutants" in rice. In the present study, fourteen previously developed rice mutant lines were analyzed for their SSR genotypes in parallel with their respective parents. Among them, eleven mutant lines had SSR genotypes identical to their parents; however, three mutant lines, i.e., Os-lpa-XS110-1, Huangyu B, and Zhu I, had 4.3, 6.6, and 9.1% of SSRs different from their parents, respectively. Additional analysis proved that Huangyu B was mistakenly recorded in the development process and should be a mutant line of another variety, II 32 B; Zhu I very probably resulted from an out-crossing rather than from mutagenesis. The implications of our findings are discussed in the context of induced mutantfacilitated gene discovery.
    Keywords parents ; rice ; genetic variation ; genes ; parentage ; quality control ; mutagenesis ; microsatellite repeats ; Oryza sativa ; genotype ; outcrossing ; mutants
    Language English
    Document type Article
    ISSN 0792-9978
    Database AGRIS - International Information System for the Agricultural Sciences and Technology

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  9. Article: Functional molecular markers and high-resolution melting curve analysis of low phytic acid mutations for marker-assisted selection in rice

    Tan, Yuan-Yuan / Fu, Hao-Wei / Zhao, Hai-Jun / Lu, Sha / Fu, Jun-Jie / Li, You-Fa / Cui, Hai-Rui / Shu, Qing-Yao

    Molecular breeding

    Volume v. 31,, Issue no. 3

    Abstract: Phytic acid (PA, myo-inositol-1,2,3,4,5,6-hexakis-phosphate) and its salt form (phytate) are the principal storage forms of phosphorus in cereal grains. Since PA and phytates cannot be efficiently digested by monogastric animals, the abundance of PA in ... ...

    Abstract Phytic acid (PA, myo-inositol-1,2,3,4,5,6-hexakis-phosphate) and its salt form (phytate) are the principal storage forms of phosphorus in cereal grains. Since PA and phytates cannot be efficiently digested by monogastric animals, the abundance of PA in cereal and legume grains causes nutritional and environmental problems. The present study aimed at developing breeder-friendly functional molecular markers of five low phytic acid (LPA) mutant alleles of three rice (Oryza sativa L.) genes: viz., XQZ-lpa (a 1,475-bp deletion) and KBNT-lpa (a C→T single nucleotide polymorphism [SNP]) of LOC_Os02g57400, Z9B-lpa (a 6-bp deletion) and MH-lpa (a 1-bp deletion) of LOC_Os04g55800, and XS-lpa (a C→T SNP) of LOC_Os03g04920. First, markers for gel-based length polymorphism analysis were developed: viz., two insertion–deletion markers for XQZ-lpa and Z9B-lpa, two cleaved amplified polymorphic sequence (CAPS) markers for KBNT-lpa and XS-lpa, and one derived CAPS marker for MH-lpa. Second, the high-resolution melting (HRM) curve analysis method was explored for distinguishing plants with wild-type (WT) and LPA alleles (except XQZ-lpa). Plants of genotypes with homozygous mutant allele and WT, and with heterozygous alleles, could be directly differentiated by HRM for KBNT-lpa, XS-lpa and MH-lpa; only heterozygous individuals could be directly distinguished from homozygous WT and mutant plants for Z9B-lpa. However, by adding 15 % WT DNA templates to test samples before PCR, amplicons of three genotypes of the Z9B-lpa allele could also be differentiated by HRM analysis. Third, it was demonstrated that these markers could be effectively used for marker-assisted selection of LPA rice, and breeding lines with two non-allelic LPA mutations were developed with PA contents significantly lower than their respective parental LPA lines. Taken together, the present study developed functional molecular markers for efficient selection of LPA plants and demonstrated that double mutant LPA lines with significantly lower PA levels than primary LPA mutants (with single mutations) could be developed by pyramiding two non-allelic LPA mutations.
    Keywords rice ; breeding lines ; single nucleotide polymorphism ; alleles ; Oryza sativa ; phosphorus ; genetic markers ; genotype ; marker-assisted selection ; mutants ; phytic acid ; melting ; DNA ; legumes ; polymerase chain reaction
    Language English
    Document type Article
    ISSN 1380-3743
    Database AGRIS - International Information System for the Agricultural Sciences and Technology

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  10. Article: down-regulated epi-allele of the genomes uncoupled 4 gene generates a xantha marker trait in rice

    Li, Rui-Qing / Huang, Jian-Zhong / Zhao, Hai-Jun / Fu, Hao-Wei / Li, You-Fa / Liu, Guo-Zhen / Shu, Qing-Yao

    Theoretical and applied genetics

    Volume v. 127,, Issue no. 1

    Abstract: KEY MESSAGE : A γ-ray-induced xantha trait is epigenetically controlled by the genomes uncoupled 4 gene with enhanced promoter segment methylation and down-regulated expression in rice. For easy testing and to increase varietal purity, a xantha mutation ( ...

    Abstract KEY MESSAGE : A γ-ray-induced xantha trait is epigenetically controlled by the genomes uncoupled 4 gene with enhanced promoter segment methylation and down-regulated expression in rice. For easy testing and to increase varietal purity, a xantha mutation (xnt), which turns plants yellow and makes them visually distinguishable from normal green rice, has been generated and bred into male sterile lines for hybrid rice production. The xnt locus was previously fine mapped to a ~100-kb interval on chromosome 11, but its identity was unknown. In this study, xnt was further narrowed down to a 57-kb fragment carrying eight opening reading frames (ORFs). All eight ORFs had identical genomic sequences and all but ORF2 (g enomes uncoupled 4, OsGUN4) had similar transcript abundance in the xantha mutant Huangyu B (HYB) and its parental variety Longtefu B (LTB). The expression of OsGUN4, however, was significantly reduced in HYB compared with LTB in terms of both transcript abundance (0.2 % that of LTB) and expressed protein level (barely detectable in HYB but greater than the heat shock protein reference in LTB). Therefore, OsGUN4 was identified as the candidate gene underlying the xantha trait. The function of OsGUN4 in the xantha phenotype was confirmed by identification and characterization of new allelic OsGUN4 mutations. Comparative bisulfite genomic sequencing of OsGUN4 revealed increased methylation in a promoter region in the mutant, and the correlation between increased methylation and the xantha phenotype was further verified by demethylation treatment. In summary, we have identified an epi-allele of OsGUN4 as the causal gene of the xantha marker trait and revealed that enhanced methylation in its promoter down-regulated its expression in rice.
    Keywords heat shock proteins ; methylation ; rice ; genes ; mutation ; Oryza sativa ; loci ; crop production ; phenotype ; gene expression regulation ; mutants ; hybrids ; sequence analysis ; promoter regions
    Language English
    Document type Article
    ISSN 0040-5752
    Database AGRIS - International Information System for the Agricultural Sciences and Technology

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