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3.
J Clin Biochem Nutr ; 72(3): 270-277, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37251961

RESUMO

Age-related changes in physical function are closely associated with daily activity impairment among the elderly. Continuous maslinic acid intake may improve skeletal muscle mass; however, the concentration-dependent benefits of maslinic acid for physical functionality remain unclear. Therefore, we evaluated the bioavailability of maslinic acid and examined the effect of maslinic acid intake on skeletal muscle and quality of life in the healthy Japanese elderly. Five healthy adult men were administered test diets containing 30, 60, or 120 mg of maslinic acid. Analysis of plasma maslinic acid revealed concentration-dependent elevations in blood maslinic acid levels (p<0.01). Next, 69 healthy Japanese adult men and women were administered a placebo or 30 or 60 mg of maslinic acid continuously for 12 weeks with physical exercise in a randomized, double-blind, placebo-controlled trial. The trunk muscle mass (p<0.05) and vitality score according to the Short-Form-8 (p<0.05) were significantly higher in the 60 mg maslinic acid group than in the placebo group. Additionally, grip strength was significantly higher in the 30 (p<0.05) and 60 mg (p<0.05) groups than in the placebo group. Overall, maslinic acid intake with physical exercise improved muscle strength, muscle mass, and quality of life in a maslinic acid-intake-dependent manner.

4.
Front Plant Sci ; 14: 1116289, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36778680

RESUMO

In pollen and pollen tubes, immotile sperm cells are enclosed by an inner vegetative plasma membrane (IVPM), a single endomembrane originating from the vegetative-cell plasma membrane. It is widely believed that sperm cells must be removed from the IVPM prior to gamete associations and fusions; however, details of the timing and morphological changes upon IVPM dissociation remain elusive. Here, we report a rapid IVPM breakdown immediately before double fertilization in Arabidopsis thaliana. The IVPM was stably observed in coiling pollen tubes when pollen tube discharge was prevented using lorelei mutant ovules. In contrast, a semi-in vivo fertilization assay in wild-type ovules demonstrated fragmented IVPM around sperm nuclei 1 min after pollen tube discharge. These observations revealed the dynamic alteration of released sperm cells and provided new insights into double fertilization in flowering plants. With a summary of recent findings on IVPM lipid composition, we discussed the possible physiological signals controlling IVPM breakdown.

5.
Plant Cell ; 35(4): 1222-1240, 2023 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-36562145

RESUMO

Pollen tube attraction is a key event of sexual reproduction in flowering plants. In the ovule, two synergid cells neighboring the egg cell control pollen tube arrival via the active secretion of attractant peptides such as AtLURE1 and XIUQIU from the filiform apparatus (FA) facing toward the micropyle. Distinctive cell polarity together with longitudinal F-actin and microtubules are hallmarks of the synergid cell in various species, though the functions of these cellular structures are unclear. In this study, we used genetic and pharmacological approaches to indicate the roles of cytoskeletal components in FA formation and pollen tube guidance in Arabidopsis thaliana. Genetic inhibition of microtubule formation reduced invaginations of the plasma membrane but did not abolish micropylar AtLURE1.2 accumulation. By contrast, the expression of a dominant-negative form of ACTIN8 induced disorganization of the FA and loss of polar AtLURE1.2 distribution toward the FA. Interestingly, after pollen tube reception, F-actin became unclear for a few hours in the persistent synergid cell, which may be involved in pausing and resuming pollen tube attraction during early polytubey block. Our data suggest that F-actin plays a central role in maintaining cell polarity and in mediating male-female communication in the synergid cell.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Actinas/genética , Actinas/metabolismo , Tubo Polínico/genética , Tubo Polínico/metabolismo , Membrana Celular/metabolismo , Óvulo Vegetal/genética , Óvulo Vegetal/metabolismo
6.
Plant Cell Physiol ; 64(1): 117-123, 2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36264192

RESUMO

Apomixis, defined as the transfer of maternal germplasm to offspring without fertilization, enables the fixation of F1-useful traits, providing advantages in crop breeding. However, most apomictic plants require pollination to produce the endosperm. The endosperm is essential for embryogenesis, and its development is suppressed until fertilization. We show that the expression of a chimeric repressor of the Elongation of Siliques without Pollination 3 (ESP3) gene (Pro35S:ESP3-SRDX) induces ovule enlargement without fertilization in Arabidopsis thaliana. The ESP3 gene encodes a protein similar to the flowering Wageningen homeodomain transcription factor containing a StAR-related lipid transfer domain. However, ESP3 lacks the homeobox-encoding region. Genes related to the cell cycle and sugar metabolism were upregulated in unfertilized Pro35S:ESP3-SRDX ovules similar to those in fertilized seeds, while those related to autophagy were downregulated similar to those in fertilized seeds. Unfertilized Pro35S:ESP3-SRDX ovules partially nourished embryos when only the egg was fertilized, accumulating hexoses without central cell proliferation. ESP3 may regulate nutrient flow during seed development, and ESP3-SRDX could be a useful tool for complete apomixis that does not require pseudo-fertilization.


Assuntos
Arabidopsis , Polinização , Sementes/metabolismo , Endosperma/genética , Reprodução , Arabidopsis/genética , Desenvolvimento Embrionário , Óvulo Vegetal/genética
7.
Nutrients ; 14(13)2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35807759

RESUMO

The single nucleotide polymorphisms (SNPs) rs3808607, rs2072183, rs2032582, and rs1761667 are associated with coenzyme Q10 (CoQ10) bioavailability in women after long-term CoQ10 supplementation. However, the beneficial aspects of the association between these SNPs and CoQ10 supplementation remain unknown. We investigated their relationship using the subjective quality of life score SF-36 by reanalyzing previous data from 92 study participants who were receiving ubiquinol (a reduced form of CoQ10) supplementation for 1 year. Two-way repeated-measures analysis of variance revealed a significant interaction between rs1761667 and the SF-36 scores of role physical (p = 0.016) and mental health (p = 0.017) in women. Subgrouping of participants based on the above four SNPs revealed significant interactions between these SNPs and the SF-36 scores of general health (p = 0.045), role emotional (p = 0.008), and mental health (p = 0.019) and increased serum CoQ10 levels (p = 0.008), suggesting that the benefits of CoQ10 supplementation, especially in terms of psychological parameters, are genotype-dependent in women. However, significant interactions were not observed in men. Therefore, inclusion of SNP subgrouping information in clinical trials of CoQ10 supplementation may provide conclusive evidence supporting other beneficial health effects exerted by the association between these SNPs and CoQ10 on women.


Assuntos
Qualidade de Vida , Ubiquinona , Subfamília B de Transportador de Cassetes de Ligação de ATP , Antioxidantes , Disponibilidade Biológica , Colesterol 7-alfa-Hidroxilase , Suplementos Nutricionais , Feminino , Humanos , Masculino , Proteínas de Membrana Transportadoras
8.
Plant J ; 109(5): 1035-1047, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35128739

RESUMO

The repression of transcription from transposable elements (TEs) by DNA methylation is necessary to maintain genome integrity and prevent harmful mutations. However, under certain circumstances, TEs may escape from the host defense system and reactivate their transcription. In Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa), DNA demethylases target the sequences derived from TEs in the central cell, the progenitor cell for the endosperm in the female gametophyte. Genome-wide DNA demethylation is also observed in the endosperm after fertilization. In the present study, we used a custom microarray to survey the transcripts generated from TEs during rice endosperm development and at selected time points in the embryo as a control. The expression patterns of TE transcripts are dynamically up- and downregulated during endosperm development, especially those of miniature inverted-repeat TEs (MITEs). Some TE transcripts were directionally controlled, whereas the other DNA transposons and retrotransposons were not. We also discovered the NUCLEAR FACTOR Y binding motif, CCAAT, in the region near the 5' terminal inverted repeat of Youren, one of the transcribed MITEs in the endosperm. Our results uncover dynamic changes in TE activity during endosperm development in rice.


Assuntos
Arabidopsis , Oryza , Arabidopsis/genética , Metilação de DNA/genética , Elementos de DNA Transponíveis/genética , Endosperma/genética , Genoma de Planta , Oryza/genética , Retroelementos/genética
9.
J Exp Biol ; 224(13)2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34170318

RESUMO

Nutrient transfer from mother to embryo is essential for reproduction in viviparous animals. In the viviparous teleost Xenotoca eiseni (family Goodeidae), the intraovarian embryo intakes the maternal component secreted into the ovarian fluid via the trophotaenia. Our previous study reported that the epithelial layer cells of the trophotaenia incorporate a maternal protein via vesicle trafficking. However, the molecules responsible for the absorption were still elusive. Here, we focused on Cubam (Cubilin-Amnionless) as a receptor involved in the absorption, and cathepsin L as a functional protease in the vesicles. Our results indicated that the Cubam receptor is distributed in the apical surface of the trophotaenia epithelium and then is taken into the intracellular vesicles. The trophotaenia possesses acidic organelles in epithelial layer cells and cathepsin L-dependent proteolysis activity. This evidence does not conflict with our hypothesis that receptor-mediated endocytosis and proteolysis play roles in maternal macromolecule absorption via the trophotaenia in viviparous teleosts. Such nutrient absorption involving endocytosis is not a specific trait in viviparous fish. Similar processes have been reported in the larval stage of oviparous fish or the suckling stage of viviparous mammals. Our findings suggest that the viviparous teleost acquired trophotaenia-based viviparity from a modification of the intestinal absorption system common in vertebrates. This is a fundamental study to understand the strategic variation of the reproductive system in vertebrates.


Assuntos
Ciprinodontiformes , Viviparidade não Mamífera , Animais , Endocitose , Feminino , Ovário , Oviparidade
10.
BMC Gastroenterol ; 21(1): 237, 2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34030638

RESUMO

BACKGROUND: We conducted a randomized controlled trial to investigate the effects of consumption of yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 in women healthcare workers. In a previous study we used these data to investigate hypothesized preventive effects against flu, however any effects on improving mental quality of life were not analyzed at that time. In the present study, we focus on that aspect. METHODS: The participants (961 women; mainly nurses, aged 20-71 years) were randomly allocated to either the yogurt group (n = 479) or the control group (n = 482). Participants in the yogurt group drank 112 mL of OLL1073R-1 yogurt for 16 weeks, while those in the control group did not consume any yogurt. All participants were prohibited from consuming other yogurt or fermented dairy products during the study period. The participants answered the Pittsburgh Sleep Quality Index (PSQI), Short Form-8 Health Survey (SF-8), and Gastrointestinal Symptom Rating Scale (GSRS) questionnaires at baseline and after 16 weeks. RESULTS: The PSQI score showed significant improvement after the intake of yogurt (p < 0.01). SF-8 results showed significant intervention effects in the General Health and Vitality scores (p = 0.02 and p = 0.01, respectively). In other subscales of SF-8, we did not observe significant effects of the yogurt. In the GSRS, daily intake of yogurt exerted a preventive effect on constipation (p = 0.03). CONCLUSIONS: Consumption of yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 enhances subjective psychological quality of life by improving quality of sleep and gastrointestinal condition among women healthcare workers.


Assuntos
Lactobacillus delbrueckii , Qualidade de Vida , Adulto , Idoso , Feminino , Pessoal de Saúde , Humanos , Pessoa de Meia-Idade , Inquéritos e Questionários , Iogurte , Adulto Jovem
11.
Nat Commun ; 12(1): 2331, 2021 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-33888710

RESUMO

During the double fertilization process, pollen tubes deliver two sperm cells to an ovule containing the female gametes. In the pollen tube, the vegetative nucleus and sperm cells move together to the apical region where the vegetative nucleus is thought to play a crucial role in controlling the direction and growth of the pollen tube. Here, we report the generation of pollen tubes in Arabidopsis thaliana whose vegetative nucleus and sperm cells are isolated and sealed by callose plugs in the basal region due to apical transport defects induced by mutations in the WPP domain-interacting tail-anchored proteins (WITs) and sperm cell-specific expression of a dominant mutant of the CALLOSE SYNTHASE 3 protein. Through pollen-tube guidance assays, we show that the physiologically anuclear mutant pollen tubes maintain the ability to grow and enter ovules. Our findings provide insight into the sperm cell delivery mechanism and illustrate the independence of the tip-localized vegetative nucleus from directional growth control of the pollen tube.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Núcleo Celular/metabolismo , Tubo Polínico/crescimento & desenvolvimento , Polinização/fisiologia , Proteínas de Arabidopsis/genética , Movimento Celular/fisiologia , Fertilização/fisiologia , Glucanos/metabolismo , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Mutação , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Óvulo Vegetal/metabolismo , Plantas Geneticamente Modificadas , Tubo Polínico/citologia , Tubo Polínico/metabolismo
12.
Antioxidants (Basel) ; 10(3)2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33799730

RESUMO

Coenzyme Q10 (CoQ10), an essential component for energy production that exhibits antioxidant activity, is considered a health-supporting and antiaging supplement. However, intervention-controlled studies have provided variable results on CoQ10 supplementation benefits, which may be attributed to individual CoQ10 bioavailability differences. This study aimed to investigate the relationship between genetic polymorphisms and CoQ10 serum levels after long-term supplementation. CoQ10 levels at baseline and after one year of supplementation (150 mg) were determined, and eight single nucleotide polymorphisms (SNPs) in cholesterol metabolism and CoQ10 absorption, efflux, and cellular uptake related genes were assessed. Rs2032582 (ABCB1) and rs1761667 (CD36) were significantly associated with a higher increase in CoQ10 levels in women. In addition, in women, rs3808607 (CYP7A1) and rs2072183 (NPC1L1) were significantly associated with a higher increase in CoQ10 per total cholesterol levels. Subgroup analyses showed that these four SNPs were useful for classifying high- or low-responder to CoQ10 bioavailability after long-term supplementation among women, but not in men. On the other hand, in men, no SNP was found to be significantly associated with increased serum CoQ10. These results collectively provide novel evidence on the relationship between genetics and CoQ10 bioavailability after long-term supplementation, which may help understand and assess CoQ10 supplementation effects, at least in women.

13.
Curr Opin Plant Biol ; 61: 102032, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33744743

RESUMO

Although flowering plants and mammals have distinct life cycles and developmental programs, epigenetic information in both plant and mammalian cells is faithfully inherited across mitotic cell division. In mammals, epigenetic reprograming is a prominent process that is re-established in the zygote and germ line during early development. By contrast, plants do not produce germ cells until later in development. This difference, along with the many examples of the transmission of stable epialleles in plants, suggests that epigenetic reprograming in plants and mammals occurs via distinct mechanisms. In this review, we highlight recent advances in genome-wide epigenetic analyses in plants. These analyses provide insight into dynamic epigenetic regulation in plants and reveal unique processes that maintain genome integrity during plant sexual reproduction.


Assuntos
Epigênese Genética , Genes de Plantas , Animais , Metilação de DNA , Plantas/genética , Reprodução/genética , Zigoto
14.
Plant Cell ; 33(1): 85-103, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33751094

RESUMO

In angiosperms, endosperm development comprises a series of developmental transitions controlled by genetic and epigenetic mechanisms that are initiated after double fertilization. Polycomb repressive complex 2 (PRC2) is a key component of these mechanisms that mediate histone H3 lysine 27 trimethylation (H3K27me3); the action of PRC2 is well described in Arabidopsis thaliana but remains uncertain in cereals. In this study, we demonstrate that mutation of the rice (Oryza sativa) gene EMBRYONIC FLOWER2a (OsEMF2a), encoding a zinc-finger containing component of PRC2, causes an autonomous endosperm phenotype involving proliferation of the central cell nuclei with separate cytoplasmic domains, even in the absence of fertilization. Detailed cytological and transcriptomic analyses revealed that the autonomous endosperm can produce storage compounds, starch granules, and protein bodies specific to the endosperm. These events have not been reported in Arabidopsis. After fertilization, we observed an abnormally delayed developmental transition in the endosperm. Transcriptome and H3K27me3 ChIP-seq analyses using endosperm from the emf2a mutant identified downstream targets of PRC2. These included >100 transcription factor genes such as type-I MADS-box genes, which are likely required for endosperm development. Our results demonstrate that OsEMF2a-containing PRC2 controls endosperm developmental programs before and after fertilization.


Assuntos
Oryza/genética , Proteínas de Plantas/metabolismo , Endosperma/metabolismo , Epigênese Genética/genética , Regulação da Expressão Gênica de Plantas/genética , Mutação/genética , Proteínas de Plantas/genética , Transcriptoma/genética
15.
Aging Clin Exp Res ; 33(11): 3099-3108, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32162239

RESUMO

AIMS: In this study, the effects of licorice flavonoid oil (LFO) supplementation on mobility functions were evaluated in middle-aged and older women who underwent daily physical exercise. METHODS: The 73 women aged 59-85 years (71.2 ± 5.2 years) were randomly assigned to the LFO group (n = 37) or the placebo group (n = 36). For 16 weeks, the LFO group consumed a daily capsule containing 300 mg of LFO, while the placebo group consumed a placebo capsule. All participants were instructed to complete a strength training program during the 16 weeks and to increase their daily step count by 1000. 10-m walking speed (with/no obstruction), one-leg standing time with eyes open, handgrip strength, isometric knee extension strength, and body composition were evaluated at baseline and every eight weeks. RESULTS: In the 10-m walking speeds (with/no obstruction), LFO supplementation did not show significant improvements. One-leg standing time was significantly prolonged with LFO intake (LFO: baseline 73.9 s vs 16 weeks 93.5, placebo: baseline 82.8 vs 16 weeks 87.1, p = 0.03). In addition, a significant decrease in BMI and body fat percentage with LFO was found (p = 0.01, p = 0.03, respectively). DISCUSSION: Since a lower BMI corresponds to a lighter physical load on the lower limb, in addition, since LFO might improve skeletal muscle function by antioxidant activity, participants could stand longer and body balance control was improved. CONCLUSION: LFO supplementation improved body balance control and may contribute to fall prevention in healthy middle-aged and older women having daily physical exercise. TRIAL REGISTRATION: UMIN Clinical Trial Registry No. 000029712.


Assuntos
Gorduras Insaturadas na Dieta , Glycyrrhiza , Treinamento Resistido , Idoso , Composição Corporal , Suplementos Nutricionais , Método Duplo-Cego , Flavonoides , Força da Mão , Humanos , Japão , Pessoa de Meia-Idade , Força Muscular , Músculo Esquelético
16.
Work ; 67(2): 323-329, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33044213

RESUMO

BACKGROUND: Many overworked employees need tools to improve their depressive mood or sleep disorder. In Finland, a new device of bright light therapy was developed. OBJECTIVE: Our objective was to evaluate the effect of bright light treatment via ear canals on improving the depressive mood and sleep disorder. METHODS: We conducted a randomized, controlled, crossover designed, open-label trial. We examined 27 participants aged 23-52 years, assigned to either Early treatment or Later treatment groups. The Early treatment group used the device on weekdays for the first 4 weeks, followed by a 4-week observation period. The Later treatment group had an observation period for the first 4 weeks, followed by device treatment for the subsequent 4 weeks. Every Friday, the participants were asked to answer questionnaires: A Self-rating Depression Scale (SDS), an Athens Insomnia Scale (AIS), and a Profile of Mood States (POMS) Brief Form. RESULTS: While no significant effect was found on the SDS following treatment (p = 0.16), the AIS showed a significant improvement (p = 0.004), and the scores for the Depression (D) and Vigor (V) of POMs decreased significantly (p = 0.045, p = 0.006, respectively). CONCLUSIONS: Bright light treatment via ear canals may improve sleep quality and depressive mood.


Assuntos
Depressão , Meato Acústico Externo , Depressão/terapia , Finlândia , Humanos , Sono , Resultado do Tratamento
17.
Food Funct ; 10(12): 8129-8136, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31738351

RESUMO

Probiotics have been expected to enhance human immune function. The aim of this study was to evaluate the effects of dietary intake of yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 (OLL1073R-1) on the prevention of influenza during winter and on the activation of immunological markers among women healthcare workers. 961 women aged 20-71 years were randomly assigned to either the yogurt group (n = 479) or the control group (n = 482). Participants in the yogurt group consumed a 112 mL yogurt drink fermented with OLL1073R-1 every day for 16 weeks, whereas those in the control group consumed no yogurt during this period. All participants were instructed not to consume any other kinds of yogurt or fermented dairy products throughout this trial. The cumulative incidence rate of influenza was measured, and immunological markers were examined at the baseline and after 16 weeks. No significant difference in the incidence rate of influenza was found between the two groups (cumulative incidence rates of flu: yogurt 7.5% and control 7.7%). Natural killer (NK) cell activity did not show a significant intervention effect (p = 0.11), whereas the intervention effect on serum interferon gamma (IFN-γ) production was significant (p = 0.03). Other immunological markers did not show significant intervention effects. Consumption of OLL1073R-1 yogurt did not show a significant preventive effect against influenza or a significant enhancement in NK cell activity. However, intake of this yogurt showed an increase in IFN-γ production.


Assuntos
Influenza Humana/prevenção & controle , Interferon gama/sangue , Probióticos/administração & dosagem , Iogurte/microbiologia , Adulto , Idoso , Feminino , Fermentação , Pessoal de Saúde , Humanos , Incidência , Influenza Humana/sangue , Influenza Humana/epidemiologia , Influenza Humana/imunologia , Células Matadoras Naturais/imunologia , Lactobacillus delbrueckii/metabolismo , Pessoa de Meia-Idade , Iogurte/análise , Adulto Jovem
18.
Plant Cell Physiol ; 60(8): 1656-1665, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31076767

RESUMO

Karyogamy is a prerequisite event for plant embryogenesis, in which dynamic changes in nuclear architecture and the establishment of appropriate gene expression patterns must occur. However, the precise role of the male and female gametes in the progression of karyogamy still remains elusive. Here, we show that the sperm cell possesses the unique property to drive steady and swift nuclear fusion. When we fertilized egg cells with sperm cells in vitro, the immediate fusion of the male and female nuclei in the zygote progressed. This rapid nuclear fusion did not occur when two egg cells were artificially fused. However, the nuclear fusion of two egg nuclei could be accelerated by additional sperm entry or the exogenous application of calcium, suggesting that possible increase of cytosolic Ca2+ level via sperm entry into the egg cell efficiently can facilitate karyogamy. In contrast to zygotes, the egg-egg fusion cells failed to proliferate beyond an early developmental stage. Our transcriptional analyses also revealed the rapid activation of zygotic genes in zygotes, whereas there was no expression in fused cells without the male contribution. Thus, the male sperm cell has the ability to cause immediate karyogamy and to establish appropriate gene expression patterns in the zygote.


Assuntos
Oryza/fisiologia , Sementes/fisiologia , Zigoto/fisiologia , Fertilização/fisiologia
19.
Int J Mol Sci ; 20(10)2019 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-31130712

RESUMO

Salinity critically limits rice metabolism, growth, and productivity worldwide. Improvement of the salt resistance of locally grown high-yielding cultivars is a slow process. The objective of this study was to develop a new salt-tolerant rice germplasm using speed-breeding. Here, we precisely introgressed the hst1 gene, transferring salinity tolerance from "Kaijin" into high-yielding "Yukinko-mai" (WT) rice through single nucleotide polymorphism (SNP) marker-assisted selection. Using a biotron speed-breeding technique, we developed a BC3F3 population, named "YNU31-2-4", in six generations and 17 months. High-resolution genotyping by whole-genome sequencing revealed that the BC3F2 genome had 93.5% similarity to the WT and fixed only 2.7% of donor parent alleles. Functional annotation of BC3F2 variants along with field assessment data indicated that "YNU31-2-4" plants carrying the hst1 gene had similar agronomic traits to the WT under normal growth condition. "YNU31-2-4" seedlings subjected to salt stress (125 mM NaCl) had a significantly higher survival rate and increased shoot and root biomasses than the WT. At the tissue level, quantitative and electron probe microanalyzer studies indicated that "YNU31-2-4" seedlings avoided Na+ accumulation in shoots under salt stress. The "YNU31-2-4" plants showed an improved phenotype with significantly higher net CO2 assimilation and lower yield decline than WT under salt stress at the reproductive stage. "YNU31-2-4" is a potential candidate for a new rice cultivar that is highly tolerant to salt stress at the seedling and reproductive stages, and which might maintain yields under a changing global climate.


Assuntos
Oryza/genética , Tolerância ao Sal , Cruzamentos Genéticos , Genes de Plantas , Oryza/fisiologia , Melhoramento Vegetal , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/fisiologia , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas
20.
Proc Natl Acad Sci U S A ; 116(19): 9652-9657, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-31000601

RESUMO

Epigenetic reprogramming is required for proper regulation of gene expression in eukaryotic organisms. In Arabidopsis, active DNA demethylation is crucial for seed viability, pollen function, and successful reproduction. The DEMETER (DME) DNA glycosylase initiates localized DNA demethylation in vegetative and central cells, so-called companion cells that are adjacent to sperm and egg gametes, respectively. In rice, the central cell genome displays local DNA hypomethylation, suggesting that active DNA demethylation also occurs in rice; however, the enzyme responsible for this process is unknown. One candidate is the rice REPRESSOR OF SILENCING1a (ROS1a) gene, which is related to DME and is essential for rice seed viability and pollen function. Here, we report genome-wide analyses of DNA methylation in wild-type and ros1a mutant sperm and vegetative cells. We find that the rice vegetative cell genome is locally hypomethylated compared with sperm by a process that requires ROS1a activity. We show that many ROS1a target sequences in the vegetative cell are hypomethylated in the rice central cell, suggesting that ROS1a also demethylates the central cell genome. Similar to Arabidopsis, we show that sperm non-CG methylation is indirectly promoted by DNA demethylation in the vegetative cell. These results reveal that DNA glycosylase-mediated DNA demethylation processes are conserved in Arabidopsis and rice, plant species that diverged 150 million years ago. Finally, although global non-CG methylation levels of sperm and egg differ, the maternal and paternal embryo genomes show similar non-CG methylation levels, suggesting that rice gamete genomes undergo dynamic DNA methylation reprogramming after cell fusion.


Assuntos
DNA Glicosilases , Metilação de DNA/fisiologia , DNA de Plantas , Oryza , Proteínas de Plantas , Pólen , Arabidopsis/enzimologia , Arabidopsis/genética , DNA Glicosilases/genética , DNA Glicosilases/metabolismo , DNA de Plantas/genética , DNA de Plantas/metabolismo , Oryza/enzimologia , Oryza/genética , Óvulo Vegetal/enzimologia , Óvulo Vegetal/genética , Desenvolvimento Vegetal/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Pólen/enzimologia , Pólen/genética
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