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1.
Gene ; 770: 145353, 2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33333227

RESUMO

Since domestication, rice has cultivated in a wide range of latitudes with different day lengths. Selection of diverse natural variations in heading date and photoperiod sensitivity is critical for adaptation of rice to different geographical environments. To unravel the genetic architecture underlying natural variation of rice flowering time, we conducted a genome wide association study (GWAS) using several association analysis strategies with a diverse worldwide collection of 529 O. sativa accessions. Heading date was investigated in three environments under long-day or short-day conditions, and photosensitivity was evaluated. By dividing the whole association panel into subpopulations and performing GWAS with both linear mixed models and multi-locus mixed-models, we revealed hundreds of significant loci harboring novel candidate genes as well as most of the known flowering time genes. In total, 127 hotspots were detected in at least two GWAS. Universal genetic heterogeneity was found across subpopulations. We further detected abundant interactions between GWAS loci, especially in indica. Functional gene families were revealed from enrichment analysis of the 127 hotspots. The results demonstrated a rich of genetic interactions in rice flowering time genes and such epistatic interactions contributed to the large portions of missing heritability in GWAS. It suggests the increased complexity of genetic heterogeneity might discount the power of increasing the sample sizes in GWAS.


Assuntos
Epistasia Genética/fisiologia , Flores , Regulação da Expressão Gênica de Plantas/fisiologia , Genes de Plantas/fisiologia , Oryza , Flores/genética , Flores/crescimento & desenvolvimento , Estudo de Associação Genômica Ampla , Oryza/genética , Oryza/crescimento & desenvolvimento
2.
BMC Plant Biol ; 20(1): 561, 2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33308141

RESUMO

BACKGROUND: Rice is a typical monocotyledonous plant and an important cereal crop. The structural units of rice flowers are spikelets and florets, and floral organ development and spike germination affect rice reproduction and yield. RESULTS: In this study, we identified a novel long sterile lemma (lsl2) mutant from an EMS population. First, we mapped the lsl2 gene between the markers Indel7-22 and Indel7-27, which encompasses a 25-kb region. The rice genome annotation indicated the presence of four candidate genes in this region. Through gene prediction and cDNA sequencing, we confirmed that the target gene in the lsl2 mutant is allelic to LONG STERILE LEMMA1 (G1)/ELONGATED EMPTY GLUME (ELE), hereafter referred to as lsl2. Further analysis of the lsl2 and LSL2 proteins showed a one-amino-acid change, namely, the mutation of serine (Ser) 79 to proline (Pro) in lsl2 compared with LSL2, and this mutation might change the function of the protein. Knockout experiments showed that the lsl2 gene is responsible for the long sterile lemma phenotype. The lsl2 gene might reduce the damage induced by spike germination by decreasing the seed germination rate, but other agronomic traits of rice were not changed in the lsl2 mutant. Taken together, our results demonstrate that the lsl2 gene will have specific application prospects in future rice breeding. CONCLUSIONS: The lsl2 gene is responsible for the long sterile lemma phenotype and might reduce the damage induced by spike germination by decreasing the seed germination rate.


Assuntos
Flores/crescimento & desenvolvimento , Genes de Plantas , Genes Recessivos , Germinação/genética , Oryza/genética , Clonagem Molecular , Flores/genética , Oryza/metabolismo
3.
BMC Plant Biol ; 20(1): 559, 2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33308168

RESUMO

BACKGROUND: The 29-member Arabidopsis AHL gene family is classified into three main classes based on nucleotide and protein sequence evolutionary differences. These differences include the presence or absence of introns, type and/or number of conserved AT-hook and PPC domains. AHL gene family members are divided into two phylogenetic clades, Clade-A and Clade-B. A majority of the 29 members remain functionally uncharacterized. Furthermore, the biological significance of the DNA and peptide sequence diversity, observed in the conserved motifs and domains found in the different AHL types, is a subject area that remains largely unexplored. RESULTS: Transgenic plants overexpressing AtAHL20 flowered later than the wild type under both short and long days. Transcript accumulation analyses showed that 35S:AtAHL20 plants contained reduced FT, TSF, AGL8 and SPL3 mRNA levels. Similarly, overexpression of AtAHL20's orthologue in Camelina sativa, Arabidopsis' closely related Brassicaceae family member species, conferred a late-flowering phenotype via suppression of CsFT expression. However, overexpression of an aberrant AtAHL20 gene harboring a missense mutation in the AT-hook domain's highly conserved R-G-R core motif abolished the late-flowering phenotype. Data from targeted yeast-two-hybrid assays showed that AtAHL20 interacted with itself and several other Clade-A Type-I AHLs which have been previously implicated in flowering-time regulation: AtAHL19, AtAHL22 and AtAHL29. CONCLUSION: We showed via gain-of-function analysis that AtAHL20 is a negative regulator of FT expression, as well as other downstream flowering time regulating genes. A similar outcome in Camelina sativa transgenic plants overexpressing CsAHL20 suggest that this is a conserved function. Our results demonstrate that AtAHL20 acts as a photoperiod-independent negative regulator of transition to flowering.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Flores/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo
4.
BMC Plant Biol ; 20(1): 562, 2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33317459

RESUMO

BACKGROUND: Flower development directly affects fruit production in tomato. Despite the framework mediated by ABC genes have been established in Arabidopsis, the spatiotemporal precision of floral development in tomato has not been well examined. RESULTS: Here, we analyzed a novel tomato stamenless like flower (slf) mutant in which the development of stamens and carpels is disturbed, with carpelloid structure formed in the third whorl and ectopic formation of floral and shoot apical meristem in the fourth whorl. Using bulked segregant analysis (BSA), we assigned the causal mutation to the gene Solanum lycopersicum GT11 (SlGT11) that encodes a transcription factor belonging to Trihelix gene family. SlGT11 is expressed in the early stages of the flower and the expression becomes more specific to the primordium position corresponding to stamens and carpels in later stages of the floral development. Further RNAi silencing of SlGT11 verifies the defective phenotypes of the slf mutant. The carpelloid stamen in slf mutant indicates that SlGT11 is required for B-function activity in the third whorl. The failed termination of floral meristem and the occurrence of floral reversion in slf indicate that part of the C-function requires SlGT11 activity in the fourth whorl. Furthermore, we find that at higher temperature, the defects of slf mutant are substantially enhanced, with petals transformed into sepals, all stamens disappeared, and the frequency of ectopic shoot/floral meristem in fourth whorl increased, indicating that SlGT11 functions in the development of the three inner floral whorls. Consistent with the observed phenotypes, it was found that B, C and an E-type MADS-box genes were in part down regulated in slf mutants. CONCLUSIONS: Together with the spatiotemporal expression pattern, we suggest that SlGT11 functions in floral organ patterning and maintenance of floral determinacy in tomato.


Assuntos
Flores/crescimento & desenvolvimento , Lycopersicon esculentum/genética , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Flores/genética , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo
5.
PLoS One ; 15(10): e0239382, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33031442

RESUMO

Floral initiation plays a critical role for reproductive success in plants, especially fruit trees. However, little information is known on the mechanism of the initiation in loquat (Eriobotrya japonica Lindl.). Here, we used transcriptomic, expression and functional analysis to investigate the candidate genes in floral initiation in loquat. Comparative transcriptome analysis showed differentially expressed genes (DEGs) were mainly enriched in the metabolic pathways of plant hormone signal transduction. The DEGs were mainly involved in the gibberellin, auxin, cytokinin, abscisic acid, salicylic acid and ethylene signaling pathways. Meanwhile, some transcription factors, including MADS-box (MCM1, AGAMOUS, DEFICIENS and SRF), MYB (Myeloblastosis), TCP (TEOSINTE BRANCHED 1, CYCLOIDEA and PCF1), WOX (WUSCHEL-related homeobox) and WRKY (WRKY DNA-binding protein), were significantly differentially expressed. Among these key DEGs, we confirmed that an AGL17 ortholog EjAGL17 was significantly upregulated at the flower bud transition stage. Phylogenetic tree analysis revealed that EjAGL17 was grouped into an AGL17 clade of MADS-box transcription factors. Protein sequence alignment showed that EjAGL17 included a distinctive C-terminal domain. Subcellular localization of EjAGL17 was found only in the nucleus. Expression levels of EjAGL17 reached the highest at the development stage of flower bud transition. Moreover, ectopic expression of EjAGL17 in Arabidopsis significantly exhibited early flowering. Our study provides abundant resources of candidate genes for studying the mechanisms underlying the floral initiation in loquat and other Rosaceae species.


Assuntos
Eriobotrya/crescimento & desenvolvimento , Eriobotrya/genética , Flores/crescimento & desenvolvimento , Flores/genética , Perfilação da Expressão Gênica , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Eriobotrya/citologia , Eriobotrya/metabolismo , Filogenia , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/genética , Transporte Proteico , Transdução de Sinais
6.
Nat Commun ; 11(1): 5118, 2020 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-33046692

RESUMO

Plants monitor seasonal cues to optimize reproductive success by tuning onset of reproduction and inflorescence architecture. TERMINAL FLOWER 1 (TFL1) and FLOWERING LOCUS T (FT) and their orthologs antagonistically regulate these life history traits, yet their mechanism of action, antagonism and targets remain poorly understood. Here, we show that TFL1 is recruited to thousands of loci by the bZIP transcription factor FD. We identify the master regulator of floral fate, LEAFY (LFY) as a target under dual opposite regulation by TFL1 and FT and uncover a pivotal role of FT in promoting flower fate via LFY upregulation. We provide evidence that the antagonism between FT and TFL1 relies on competition for chromatin-bound FD at shared target loci. Direct TFL1-FD regulated target genes identify this complex as a hub for repressing both master regulators of reproductive development and endogenous signalling pathways. Our data provide mechanistic insight into how TFL1-FD sculpt inflorescence architecture, a trait important for reproductive success, plant architecture and yield.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Ligação Proteica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
7.
Nat Commun ; 11(1): 5269, 2020 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-33077749

RESUMO

Azaleas (Ericaceae) comprise one of the most diverse ornamental plants, renowned for their cultural and economic importance. We present a chromosome-scale genome assembly for Rhododendron simsii, the primary ancestor of azalea cultivars. Genome analyses unveil the remnants of an ancient whole-genome duplication preceding the radiation of most Ericaceae, likely contributing to the genomic architecture of flowering time. Small-scale gene duplications contribute to the expansion of gene families involved in azalea pigment biosynthesis. We reconstruct entire metabolic pathways for anthocyanins and carotenoids and their potential regulatory networks by detailed analysis of time-ordered gene co-expression networks. MYB, bHLH, and WD40 transcription factors may collectively regulate anthocyanin accumulation in R. simsii, particularly at the initial stages of flower coloration, and with WRKY transcription factors controlling progressive flower coloring at later stages. This work provides a cornerstone for understanding the underlying genetics governing flower timing and coloration and could accelerate selective breeding in azalea.


Assuntos
Cromossomos de Plantas/genética , Genoma de Planta , Proteínas de Plantas/genética , Rhododendron/genética , Antocianinas/biossíntese , Vias Biossintéticas , Carotenoides/metabolismo , Cromossomos de Plantas/metabolismo , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Família Multigênica , Proteínas de Plantas/metabolismo , Rhododendron/crescimento & desenvolvimento , Rhododendron/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
8.
PLoS One ; 15(9): e0239417, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32966329

RESUMO

In order to successfully reproduce, plants must sense changes in their environment and flower at the correct time. Many plants utilize day length and vernalization, a mechanism for verifying that winter has occurred, to determine when to flower. Our study used available temperature and day length data from different climates to provide a general understanding how this information processing of environmental signals could have evolved in plants. For climates where temperature fluctuation correlations decayed exponentially, a simple stochastic model characterizing vernalization was able to reconstruct the switch-like behavior of the core flowering regulatory genes. For these and other climates, artificial neural networks were used to predict flowering gene expression patterns. For temperate plants, long-term cold temperature and short-term day length measurements were sufficient to produce robust flowering time decisions from the neural networks. Additionally, evolutionary simulations on neural networks confirmed that the combined signal of temperature and day length achieved the highest fitness relative to neural networks with access to only one of those inputs. We suggest that winter temperature memory is a well-adapted strategy for plants' detection of seasonal changes, and absolute day length is useful for the subsequent triggering of flowering.


Assuntos
Flores/crescimento & desenvolvimento , Modelos Biológicos , Evolução Biológica , Tomada de Decisões , Redes Neurais de Computação , Temperatura , Fatores de Tempo
9.
PLoS One ; 15(9): e0239123, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32925982

RESUMO

Cultivated diversity is considered an insurance against major climatic variability. However, since the 1980s, several studies have shown that climate variability and agricultural changes may already have locally eroded crop genetic diversity. We studied pearl millet diversity in Senegal through a comparison of pearl millet landraces collected 40 years apart. We found that more than 20% of villages visited in 1976 had stopped growing pearl millet. Despite this, its overall genetic diversity has been maintained but differentiation between early- and late-flowering accessions has been reduced. We also found stronger crop-to-wild gene flow than wild-to-crop gene flow and that wild-to-crop gene flow was weaker in 2016 than in 1976. In conclusion, our results highlight genetic homogenization in Senegal. This homogenization within cultivated pearl millet and between wild and cultivated forms is a key factor in genetic erosion and it is often overlooked. Improved assessment and conservation strategies are needed to promote and conserve both wild and cultivated pearl millet diversity.


Assuntos
Produção Agrícola/tendências , Produtos Agrícolas/genética , Evolução Molecular , Variação Genética , Pennisetum/genética , Conservação dos Recursos Naturais , Produção Agrícola/história , Produção Agrícola/estatística & dados numéricos , DNA de Plantas/genética , DNA de Plantas/isolamento & purificação , Flores/crescimento & desenvolvimento , Fluxo Gênico , História do Século XX , História do Século XXI , Senegal
10.
Plant Mol Biol ; 104(4-5): 529-548, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32876816

RESUMO

KEY MESSAGE: This research provides comprehensive insight into the molecular networks and molecular mechanisms underlying D. officinale flower development. Flowers are complex reproductive organs and play a crucial role in plant propagation, while also providing sustenance for insects and natural bioactive metabolites for humans. However, knowledge about gene regulation and floral metabolomes in flowers is limited. In this study, we used an important orchid species (Dendrobium officinale), whose flowers can be used to make herbal tea, to perform transcriptome sequencing and metabolic profiling of early- and medium-stage flower buds, as well as opened flowers, to provide comprehensive insight into the molecular mechanisms underlying flower development. A total of 8019 differentially expressed genes (DEGs) and 239 differentiated metabolites were found. The transcription factors that were identified and analyzed belong exclusively to the MIKC-type MADS-box proteins and auxin responsive factors that are known to be involved in flower development. The expression of genes involved in chlorophyll and carotenoid biosynthesis strongly matched the metabolite accumulation patterns. The genes related to flavonoid and polysaccharide biosynthesis were active during flower development. Interestingly, indole-3-acetic acid and abscisic acid, whose trend of accumulation was inverse during flower development, may play an important role in this process. Collectively, the identification of DEGs and differentiated metabolites could help to illustrate the regulatory networks and molecular mechanisms important for flower development in this orchid.


Assuntos
Dendrobium/crescimento & desenvolvimento , Dendrobium/genética , Dendrobium/metabolismo , Flores/crescimento & desenvolvimento , Ácido Abscísico/metabolismo , Carotenoides/metabolismo , Clorofila/metabolismo , Flavonoides/metabolismo , Flores/genética , Flores/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Proteínas de Domínio MADS/genética , Filogenia , Proteínas de Plantas/genética , Polissacarídeos/metabolismo
11.
PLoS One ; 15(8): e0236351, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785293

RESUMO

Hybrid performance during wheat breeding can be improved by analyzing genetic distance (GD) among wheat genotypes and determining its correlation with heterosis. This study evaluated the GD between 16 wheat genotypes by using 60 simple sequence repeat (SSR) markers to classify them according to their relationships and select those with greater genetic diversity, evaluate the correlation of the SSR marker distance with heterotic performance and specific combining ability (SCA) for heat stress tolerance, and identify traits that most influence grain yield (GY). Eight parental genotypes with greater genetic diversity and their 28 F1 hybrids generated using diallel crossing were evaluated for 12 measured traits in two seasons. The GD varied from 0.235 to 0.911 across the 16 genotypes. Cluster analysis based on the GD estimated using SSRs classified the genotypes into three major groups and six sub-groups, almost consistent with the results of principal coordinate analysis. The combined data indicated that five hybrids showed 20% greater yield than mid-parent or better-parent. Two hybrids (P2 × P4) and (P2 × P5), which showed the highest performance of days to heading (DH), grain filling duration (GFD), and GY, and had large genetic diversity among themselves (0.883 and 0.911, respectively), were deemed as promising heat-tolerant hybrids. They showed the best mid-parent heterosis and better-parent heterosis (BPH) for DH (-11.57 and -7.65%; -13.39 and -8.36%, respectively), GFD (12.74 and 12.17%; 12.09 and 10.59%, respectively), and GY (36.04 and 20.04%; 44.06 and 37.73%, respectively). Correlation between GD and each of BPH and SCA effects based on SSR markers was significantly positive for GFD, hundred kernel weight, number of kernels per spike, harvest index, GY, and grain filling rate and was significantly negative for DH. These correlations indicate that the performance of wheat hybrids with high GY and earliness could be predicted by determining the GD of the parents by using SSR markers. Multivariate analysis (stepwise regression and path coefficient) suggested that GFD, hundred kernel weight, days to maturity, and number of kernels per spike had the highest influence on GY.


Assuntos
Resposta ao Choque Térmico/genética , Vigor Híbrido/genética , Seleção Genética/genética , Triticum/genética , Pão , Cruzamento , Grão Comestível/genética , Grão Comestível/crescimento & desenvolvimento , Flores/genética , Flores/crescimento & desenvolvimento , Genótipo , Humanos , Hibridização Genética/genética , Repetições de Microssatélites/genética , Fenótipo , Triticum/crescimento & desenvolvimento
12.
Proc Natl Acad Sci U S A ; 117(35): 21747-21756, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32817425

RESUMO

Arabidopsis AINTEGUMENTA (ANT), an AP2 transcription factor, is known to control plant growth and floral organogenesis. In this study, our transcriptome analysis and in situ hybridization assays of maize embryonic leaves suggested that maize ANT1 (ZmANT1) regulates vascular development. To better understand ANT1 functions, we determined the binding motif of ZmANT1 and then showed that ZmANT1 binds the promoters of millet SCR1, GNC, and AN3, which are key regulators of Kranz anatomy, chloroplast development, and plant growth, respectively. We generated a mutant with a single-codon deletion and two frameshift mutants of the ANT1 ortholog in the C4 millet Setaria viridis by the CRISPR/Cas9 technique. The two frameshift mutants displayed reduced photosynthesis efficiency and growth rate, smaller leaves, and lower grain yields than wild-type (WT) plants. Moreover, their leaves sporadically exhibited distorted Kranz anatomy and vein spacing. Conducting transcriptomic analysis of developing leaves in the WT and the three mutants we identified differentially expressed genes (DEGs) in the two frameshift mutant lines and found many down-regulated DEGs enriched in photosynthesis, heme, tetrapyrrole binding, and antioxidant activity. In addition, we predicted many target genes of ZmANT1 and chose 13 of them to confirm binding of ZmANT1 to their promoters. Based on the above observations, we proposed a model for ANT1 regulation of cell proliferation and leaf growth, vascular and vein development, chloroplast development, and photosynthesis through its target genes. Our study revealed biological roles of ANT1 in several developmental processes beyond its known roles in plant growth and floral organogenesis.


Assuntos
Translocador 1 do Nucleotídeo Adenina/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/genética , Translocador 1 do Nucleotídeo Adenina/fisiologia , Sistemas de Transporte de Aminoácidos Neutros/genética , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Cloroplastos/metabolismo , Flores/genética , Flores/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Milhetes/genética , Milhetes/metabolismo , Organogênese Vegetal/genética , Fotossíntese/genética , Fotossíntese/fisiologia , Desenvolvimento Vegetal/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Fatores de Transcrição/metabolismo , Transcriptoma
13.
PLoS One ; 15(7): e0235397, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32628713

RESUMO

Appropriate flowering and maturity time are important for soybean production. Four maturity genes E1, E2, E3 and E4 have been molecularly identified and found to play major roles in the control of flowering and maturity of soybean. Here, to further investigate the effect of different allele combinations of E1-E4, we performed Kompetitive Allele Specific PCR (KASP) assays based on single nucleotide polymorphisms (SNPs) at these four E loci, and genotyped E1-E4 genes across 308 Chinese cultivars with a wide range of maturity groups. In total, twenty-one allele combinations for E1-E4 genes were identified across these Chinese cultivars. Various combinations of mutations at four E loci gave rise to the diversity of flowering and maturity time, which were associated with the adaptation of soybean cultivars to diverse geographic regions and farming systems. In particular, the cultivars with mutations at all four E loci reached flowering and maturity very early, and adapted to high-latitude cold regions. The allele combinations e1-as/e2-ns/e3-tr/E4, E1/e2-ns/E3/E4 and E1/E2/E3/E4 played important roles in the Northeast China, Huang-Huai-Hai (HHH) Rivers Valley and South China regions, respectively. Notably, E1 and E2, especially E2, affected flowering and maturity time of soybean significantly. Our study will be beneficial for germplasm evaluation, cultivar improvement and regionalization of cultivation in soybean production.


Assuntos
Adaptação Fisiológica/genética , Regulação da Expressão Gênica de Plantas , Genes Controladores do Desenvolvimento , Locos de Características Quantitativas , Soja/fisiologia , Alelos , China , Produção Agrícola , Fazendas , Flores/crescimento & desenvolvimento , Genes de Plantas , Variação Genética , Genótipo , Geografia , Fotoperíodo , Fatores de Tempo
14.
Mol Genet Genomics ; 295(6): 1459-1476, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32683543

RESUMO

Polyploidy promotes morphological, physiological, and reproductive diversity in plants. The imminent effect of chromosome doubling in plants is the enlargement of organs such as flowers and fruits, which increases the commercial value of crops. Flowering plays a vital role in the growth and development of angiosperms. Here, we prepared an isolated microspore culture of 'FT', a doubled haploid (DH) line of Chinese cabbage (Brassica rapa L. ssp. pekinensis), and obtained diploid and autotetraploid plants with the same genetic background. Compared with diploids, the autotetraploids were characterized by large floral organs, dark petals, delayed flowering, and reduced fertility. The indole-3-acetic acid (IAA) and jasmonic acid (JA) levels in autotetraploid petals were significantly higher and the abscisic acid (ABA) level was significantly lower than those in the diploid petals. The lutein level in autotetraploid petals was nearly two times higher than that in the diploid petals. A comparative transcriptome analysis revealed 14,412 differentially expressed genes (DEGs) between the diploids and autotetraploids, and they were enriched in 117 Gene Ontology terms and 110 Kyoto Encyclopedia of Genes and Genomes pathways. We detected 231 DEGs related to phytohormone signal transduction and 29 DEGs involved in carotenoid biosynthesis. An miRNA-target mRNA analysis showed that 32 DEGs regulated by 16 DEMs were associated with flowering timing (BraA03000336, BraA09004319, and BraA09000515), petal development (BraA05002408, BraA01004006, BraA09004069, and BraA04000966), flower opening (BraA07000350), and pollen development (BraA01000720, BraA09005727, and BraA01000253). This study provides information to help elucidate the molecular mechanisms underlying phenotypic variations induced by autopolyploidy in Chinese cabbage.


Assuntos
Brassica rapa/genética , Diploide , Flores/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Pequeno RNA não Traduzido/genética , Tetraploidia , Brassica rapa/crescimento & desenvolvimento , Flores/classificação , Flores/crescimento & desenvolvimento , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/genética , RNA-Seq , Transcriptoma
15.
Plant Mol Biol ; 104(1-2): 187-201, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32681357

RESUMO

KEY MESSAGE: The mutation of FAX1 (Fatty Acid Export 1) disrupts ROS homeostasis and suppresses transcription activity of DYT1-TDF1-AMS-MS188 genetic network, leading to atypical tapetum PCD and defective pollen formation in Arabidopsis. Fatty acids (FAs) have multiple important biological functions and exert diverse cellular effects through modulating Reactive Oxygen Species (ROS) homeostasis. Arabidopsis FAX1 (Fatty Acid Export 1) mediates the export of de novo synthesized FA from chloroplast and loss of function of FAX1 impairs male fertility. However, mechanisms underlying the association of FAX1-mediated FA export with male sterility remain enigmatic. In this study, by using an integrated approach that included morphological, cytological, histological, and molecular analyses, we revealed that loss of function of FAX1 breaks cellular FA/lipid homeostasis, which disrupts ROS homeostasis and suppresses transcriptional activation of the DYT1-TDF1-AMS-MS188 genetic network of anther development, impairing tapetum development and pollen wall formation, and resulting in male sterility. This study provides new insights into the regulatory network for male reproduction in plants, highlighting an important role of FA export-mediated ROS homeostasis in the process.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ácidos Graxos/metabolismo , Proteínas de Membrana/metabolismo , Pólen/metabolismo , Arabidopsis/citologia , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Flores/citologia , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Redes Reguladoras de Genes , Proteínas de Membrana/genética , Mutação , Fenótipo , Pólen/genética , Reprodução , Fatores de Transcrição
16.
PLoS Genet ; 16(7): e1008882, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32673315

RESUMO

Expansion of the maize growing area was central for food security in temperate regions. In addition to the suppression of the short-day requirement for floral induction, it required breeding for a large range of flowering time that compensates the effect of South-North gradients of temperatures. Here we show the role of a novel florigen gene, ZCN12, in the latter adaptation in cooperation with ZCN8. Strong eQTLs of ZCN8 and ZCN12, measured in 327 maize lines, accounted for most of the genetic variance of flowering time in platform and field experiments. ZCN12 had a strong effect on flowering time of transgenic Arabidopsis thaliana plants; a path analysis showed that it directly affected maize flowering time together with ZCN8. The allelic composition at ZCN QTLs showed clear signs of selection by breeders. This suggests that florigens played a central role in ensuring a large range of flowering time, necessary for adaptation to temperate areas.


Assuntos
Adaptação Fisiológica/genética , Florígeno/metabolismo , Proteínas de Plantas/genética , Zea mays/genética , Aclimatação/genética , Temperatura Baixa , Flores/genética , Flores/crescimento & desenvolvimento , Humanos , Fotoperíodo , Proteínas de Plantas/metabolismo , Locos de Características Quantitativas/genética , Zea mays/crescimento & desenvolvimento
17.
PLoS Genet ; 16(7): e1008812, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32658893

RESUMO

In Arabidopsis, CONSTANS (CO) integrates light and circadian clock signals to promote flowering under long days (LD). In the grasses, a duplication generated two paralogs designated as CONSTANS1 (CO1) and CONSTANS2 (CO2). Here we show that in tetraploid wheat plants grown under LD, combined loss-of-function mutations in the A and B-genome homeologs of CO1 and CO2 (co1 co2) result in a small (3 d) but significant (P<0.0001) acceleration of heading time both in PHOTOPERIOD1 (PPD1) sensitive (Ppd-A1b, functional ancestral allele) and insensitive (Ppd-A1a, functional dominant allele) backgrounds. Under short days (SD), co1 co2 mutants headed 13 d earlier than the wild type (P<0.0001) in the presence of Ppd-A1a. However, in the presence of Ppd-A1b, spikes from both genotypes failed to emerge by 180 d. These results indicate that CO1 and CO2 operate mainly as weak heading time repressors in both LD and SD. By contrast, in ppd1 mutants with loss-of-function mutations in both PPD1 homeologs, the wild type Co1 allele accelerated heading time >60 d relative to the co1 mutant allele under LD. We detected significant genetic interactions among CO1, CO2 and PPD1 genes on heading time, which were reflected in complex interactions at the transcriptional and protein levels. Loss-of-function mutations in PPD1 delayed heading more than combined co1 co2 mutations and, more importantly, PPD1 was able to perceive and respond to differences in photoperiod in the absence of functional CO1 and CO2 genes. Similarly, CO1 was able to accelerate heading time in response to LD in the absence of a functional PPD1. Taken together, these results indicate that PPD1 and CO1 are able to respond to photoperiod in the absence of each other, and that interactions between these two photoperiod pathways at the transcriptional and protein levels are important to fine-tune the flowering response in wheat.


Assuntos
Epistasia Genética/genética , Fotoperíodo , Proteínas de Plantas/genética , Triticum/genética , Alelos , Arabidopsis , Relógios Circadianos/genética , Ritmo Circadiano/genética , Flores/genética , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas/genética , Genótipo , Fatores de Transcrição/genética , Triticum/crescimento & desenvolvimento
18.
Mol Genet Genomics ; 295(5): 1187-1195, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32476049

RESUMO

Cowpea (Vigna unguiculate (L.) Walp.) is a worldwide important multifunctional legume crop for food grain, vegetable, fodder, and cover crop. Nevertheless, only limited research has been conducted on agronomic traits. Here, we report quantitative trait locus (QTL) analysis of the days to flowering (DTF) and plant height (PH) using a dense SNP linkage map recently developed from a recombinant inbred line (RIL) population derived from a cross between Golden Eye Cream and IT98K-476-8. The population was phenotyped for DTF and PH through field and greenhouse trials under two environments. The QTLs controlling these traits were mapped using multiple-environment combined and individual trial phenotypic data. The combined data analysis identified one major QTL (qDTF9.1) for DTF, and one major QTL (qPH9.1) and a minor QTL (qPH4.1) for PH. qDTF9.1 and qPH9.1 were adjacent to each other on Chromosome 9 and each explained 29.3% and 29.5% of the phenotypic variation (PVE), respectively. The individual trial data analysis identified a minor QTL (qDTF2.1) on Chromosome 2 for DTF and two minor QTLs (qPH4.1 and qPH4.2) on Chromosome 4 for PH, while the major QTLs, qDTF9.1 and qPH9.1, were consistently identified in all trials conducted. Epistasis analysis revealed that qDTF9.1 interacted with one locus on Chromosome 4, contributed 50% of the PVE, and qPH9.1 interacted with one locus on each of Chromosomes 4 and 6, contributing 30% and 23% of the PVE, respectively, suggesting that epistasis plays an important role in the trait performance. These results, therefore, provide a deeper understanding of the genetic architecture of plant DTF and PH, and molecular tools necessary for cloning the genes and for enhanced cowpea breeding.


Assuntos
Mapeamento Cromossômico/métodos , Locos de Características Quantitativas , Vigna/fisiologia , Cromossomos de Plantas/genética , Cruzamentos Genéticos , Epistasia Genética , Flores/genética , Flores/crescimento & desenvolvimento , Fenótipo , Polimorfismo de Nucleotídeo Único , Vigna/anatomia & histologia , Vigna/genética
19.
Nat Commun ; 11(1): 3115, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32561756

RESUMO

Reproduction-specific small RNAs are vital regulators of germline development in animals and plants. MicroRNA2118 (miR2118) is conserved in plants and induces the production of phased small interfering RNAs (phasiRNAs). To reveal the biological functions of miR2118, we describe here rice mutants with large deletions of the miR2118 cluster. Our results demonstrate that the loss of miR2118 causes severe male and female sterility in rice, associated with marked morphological and developmental abnormalities in somatic anther wall cells. Small RNA profiling reveals that miR2118-dependent 21-nucleotide (nt) phasiRNAs in the anther wall are U-rich, distinct from the phasiRNAs in germ cells. Furthermore, the miR2118-dependent biogenesis of 21-nt phasiRNAs may involve the Argonaute proteins OsAGO1b/OsAGO1d, which are abundant in anther wall cell layers. Our study highlights the site-specific differences of phasiRNAs between somatic anther wall and germ cells, and demonstrates the significance of miR2118/U-phasiRNA functions in anther wall development and rice reproduction.


Assuntos
Flores/crescimento & desenvolvimento , MicroRNAs/metabolismo , Oryza/crescimento & desenvolvimento , RNA de Plantas/metabolismo , RNA Interferente Pequeno/biossíntese , Proteínas Argonauta/genética , Proteínas Argonauta/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , Mutação , Organogênese Vegetal/genética , Oryza/genética , Epiderme Vegetal/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas
20.
PLoS One ; 15(5): e0232835, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32384101

RESUMO

Many plant species harbor communities of symbionts that release nutrients used by their host plants. However, the importance of these nutrients to plant growth and reproductive effort is not well understood. Here, we evaluate the relationship between the communities that colonize pitcher plant phytotelmata and the pitcher plants' vegetative growth and flower production to better understand the symbiotic role played by phytotelma communities. We focus on the mountain variety purple pitcher plant (Sarracenia purpurea var. montana), which occurs in small and isolated populations in Western North Carolina. We found that greater symbiont community diversity is associated with higher flower production the following season. We then examined geographic variation in communities and found that smaller plant populations supported less diverse symbiont communities. We relate our observations to patterns of community diversity predicted by community ecology theory.


Assuntos
Artrópodes/fisiologia , Biota/fisiologia , Sarraceniaceae/crescimento & desenvolvimento , Simbiose/fisiologia , Animais , Biodiversidade , Chironomidae/crescimento & desenvolvimento , Chironomidae/metabolismo , Copépodes/metabolismo , Culicidae/metabolismo , Flores/crescimento & desenvolvimento , Larva , Ácaros/metabolismo , Ciclo do Nitrogênio , Dispersão Vegetal , Folhas de Planta/crescimento & desenvolvimento , Reprodução , Sarraceniaceae/metabolismo
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