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1.
Cells ; 9(10)2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-33092216

RESUMO

Black spot disease, caused by Alternaria brassicicola in Brassica species, is one of the most devastating diseases all over the world, especially since there is no known fully resistant Brassica cultivar. In this study, the visualization of black spot disease development on Brassica oleracea var. capitata f. alba (white cabbage) leaves and subsequent ultrastructural, molecular and physiological investigations were conducted. Inter- and intracellular hyphae growth within leaf tissues led to the loss of host cell integrity and various levels of organelle disintegration. Severe symptoms of chloroplast damage included the degeneration of chloroplast envelope and grana, and the loss of electron denseness by stroma at the advanced stage of infection. Transcriptional profiling of infected leaves revealed that photosynthesis was the most negatively regulated biological process. However, in infected leaves, chlorophyll and carotenoid content did not decrease until 48 hpi, and several chlorophyll a fluorescence parameters, such as photosystem II quantum yield (Fv/Fm), non-photochemical quenching (NPQ), or plant vitality parameter (Rdf) decreased significantly at 24 and 48 hpi compared to control leaves. Our results indicate that the initial stages of interaction between B. oleracea and A. brassicicola are not uniform within an inoculation site and show a complexity of host responses and fungal attempts to overcome host cell defense mechanisms. The downregulation of photosynthesis at the early stage of this susceptible interaction suggests that it may be a part of a host defense strategy, or, alternatively, that chloroplasts are targets for the unknown virulence factor(s) of A. brassicicola. However, the observed decrease of photosynthetic efficiency at the later stages of infection is a result of the fungus-induced necrotic lesion expansion.


Assuntos
Alternaria/ultraestrutura , Brassica/genética , Brassica/microbiologia , Regulação para Baixo , Interações Hospedeiro-Patógeno/genética , Fotossíntese , Doenças das Plantas/microbiologia , Transcrição Genética , Alternaria/fisiologia , Brassica/fisiologia , Brassica/ultraestrutura , Clorofila A/metabolismo , Cloroplastos/metabolismo , Cloroplastos/ultraestrutura , Suscetibilidade a Doenças , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Células do Mesofilo/microbiologia , Células do Mesofilo/ultraestrutura , Fotossíntese/genética , Folhas de Planta/microbiologia , Folhas de Planta/ultraestrutura , Fatores de Tempo
2.
Nat Plants ; 6(4): 377-383, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32251374

RESUMO

The vast majority of eukaryotic cells contain mitochondria, essential powerhouses and metabolic hubs1. These organelles have a bacterial origin and were acquired during an early endosymbiosis event2. Mitochondria possess specialized gene expression systems composed of various molecular machines, including the mitochondrial ribosomes (mitoribosomes). Mitoribosomes are in charge of translating the few essential mRNAs still encoded by mitochondrial genomes3. While chloroplast ribosomes strongly resemble those of bacteria4,5, mitoribosomes have diverged significantly during evolution and present strikingly different structures across eukaryotic species6-10. In contrast to animals and trypanosomatids, plant mitoribosomes have unusually expanded ribosomal RNAs and have conserved the short 5S rRNA, which is usually missing in mitoribosomes11. We have previously characterized the composition of the plant mitoribosome6, revealing a dozen plant-specific proteins in addition to the common conserved mitoribosomal proteins. In spite of the tremendous recent advances in the field, plant mitoribosomes remained elusive to high-resolution structural investigations and the plant-specific ribosomal features of unknown structures. Here, we present a cryo-electron microscopy study of the plant 78S mitoribosome from cauliflower at near-atomic resolution. We show that most of the plant-specific ribosomal proteins are pentatricopeptide repeat proteins (PPRs) that deeply interact with the plant-specific rRNA expansion segments. These additional rRNA segments and proteins reshape the overall structure of the plant mitochondrial ribosome, and we discuss their involvement in the membrane association and mRNA recruitment prior to translation initiation. Finally, our structure unveils an rRNA-constructive phase of mitoribosome evolution across eukaryotes.


Assuntos
Brassica/ultraestrutura , Ribossomos Mitocondriais/ultraestrutura , RNA de Plantas/ultraestrutura , RNA Ribossômico/ultraestrutura , Brassica/genética , Microscopia Crioeletrônica , Evolução Molecular , Modelos Moleculares , Proteínas de Plantas/ultraestrutura , Proteínas Ribossômicas/ultraestrutura
3.
Food Chem ; 297: 124964, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253313

RESUMO

Broccoli undergoes yellowing in unfavorable conditions, thereby diminishing the sensory quality and commodity value. This study aimed to investigate systematically cellular and/or biomolecular changes involved in broccoli yellowing by analyzing changes in microstructural integrity, pigment content, and gene expression. On day-5 of storage at 20 °C, the buds turned yellow without blooming and showed structural damage; ultrastructural analysis revealed plastid transformation and abnormal chloroplast development. Genes regulating pigment content and chloroplast structure directly were identified. More specifically, BoCAO and BoNYC1 regulated chlorophyll turnover, affecting chlorophyll a and b contents. Changes in the ß-cryptoxanthin content were influenced by the combined action of up- (BoHYD) and downstream (BoZEP) genes. BoZEP and BoVDE were activated after cold-temperature induction. High BoHO1 expression delayed yellowing at low temperature, inducing BoZEP expression. Color intensity correlated significantly with the chlorophyll b, ß-cryptoxanthin, and ß-carotene contents, which were associated with increased yellowing of plant tissues.


Assuntos
Brassica/fisiologia , Carotenoides/metabolismo , Clorofila/metabolismo , Armazenamento de Alimentos , beta-Criptoxantina/genética , beta-Criptoxantina/metabolismo , Vias Biossintéticas , Brassica/ultraestrutura , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plastídeos/genética , Plastídeos/metabolismo , Temperatura
4.
Plant Biol (Stuttg) ; 20(5): 894-901, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29883021

RESUMO

Quartet pollen, where pollen grains remain attached to each other post-meiosis, is useful for tetrad analysis, crossover assessment and centromere mapping. We observed the quartet pollen phenotype for the first time in the agriculturally significant Brassica genus, in an experimental population of allohexaploid Brassica hybrids derived from the cross (Brassica napus × B. carinata) × B. juncea followed by two self-pollination generations. Quartet pollen production was assessed in 144 genotypes under glasshouse conditions, following which a set of 16 genotypes were selected to further investigate the effect of environment (warm: 25 °C and cold: 10 °C temperatures) on quartet pollen production in growth cabinets. Under glasshouse phenotyping conditions, only 92 out of 144 genotypes produced enough pollen to score: of these, 30 did not produce any observable quartet pollen, while 62 genotypes produced quartet pollen at varying frequencies. Quartet pollen production appeared quantitative and did not clearly fall into phenotypic or qualitative categories indicative of major gene expression. No consistent effect of temperature on quartet pollen production was identified, with some genotypes producing more and some producing less quartet pollen under different temperature treatments. The genetic heterogeneity and frequent pollen infertility of this population prevents strong conclusions being made. However, it is clear that the quartet phenotype in this Brassica population does not show complete penetrance and shows variable (likely genotype-specific) response to temperature stress. In future, identification of quartet phenotypes in Brassica would perhaps best be carried out via screening of diploid (e.g. B. rapa) TILLING populations.


Assuntos
Brassica/fisiologia , Pólen/ultraestrutura , Brassica/ultraestrutura , Brassica napus/fisiologia , Brassica napus/ultraestrutura , Temperatura Baixa , Genótipo , Temperatura Alta , Mostardeira/fisiologia , Mostardeira/ultraestrutura , Fenótipo , Polinização , Autofertilização
5.
BMC Plant Biol ; 18(1): 130, 2018 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-29940850

RESUMO

BACKGROUND: Plastome mutants are ideal resources for elucidating the functions of plastid genes. Numerous studies have been conducted for the function of plastid genes in barley and tobacco; however, related information is limited in Chinese cabbage. RESULTS: A chlorophyll-deficient mutant of Chinese cabbage that was derived by ethyl methanesulfonate treatment on isolated microspores showed uniformly pale green inner leaves and slow growth compared with that shown by the wild type "Fukuda 50' ('FT'). Genetic analysis revealed that cdm was cytoplasmically inherited. Physiological and ultrastructural analyses of cdm showed impaired photosynthesis and abnormal chloroplast development. Utilizing next generation sequencing, the complete plastomes of cdm and 'FT' were respectively re-mapped to the reference genome of Chinese cabbage, and an A-to-C base substitution with a mutation ratio higher than 99% was detected. The missense mutation of plastid ribosomal protein S4 led to valine substitution for glycine at residue 193. The expression level of rps4 was analyzed using quantitative real-time PCR and found lower in than in 'FT'. RNA gel-blot assays showed that the abundance of mature 23S rRNA, 16S rRNA, 5S rRNA, and 4.5S rRNA significantly decreased and that the processing of 23S, 16S rRNA, and 4.5S rRNA was seriously impaired, affecting the ribosomal function in cdm. CONCLUSIONS: These findings indicated that cdm was a plastome mutant and that chlorophyll deficiency might be due to an A-to-C base substitution of the plastome-encoded rps4 that impaired the rRNA processing and affected the ribosomal function.


Assuntos
Brassica/genética , Clorofila/deficiência , Proteínas de Plantas/genética , Plastídeos/genética , Northern Blotting , Brassica/metabolismo , Brassica/ultraestrutura , Clorofila/genética , Clorofila/metabolismo , Cloroplastos/ultraestrutura , DNA de Cloroplastos/genética , Genes de Plantas/genética , Genes de Plantas/fisiologia , Microscopia Eletrônica de Transmissão , Mitocôndrias/ultraestrutura , Mutação de Sentido Incorreto/genética , Fotossíntese/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/fisiologia , RNA Ribossômico/genética , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA
6.
Food Sci Technol Int ; 24(3): 187-197, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29141452

RESUMO

The quality parameters of sauerkraut fermented using Lactobacillus paracasei in terms of its lactic acid bacteria count, texture, colour and biochemical properties were studied. As a starter culture L. paracasei grown in tofu whey was used for sauerkraut fermentation. The experiments were planned using central composite rotatable design of response surface methodology for input variables - culture volume (ml), fermentation time (days) and salt concentration (g/100 g). The linear and interactive effect of variables on responses was understood by statistically significant (p < 0.01) second-order models. Amongst all the input variables culture volume was found to have an overwhelming effect over all the responses. There was a significant (p < 0.01) increase in the lactic acid bacteria count of finished product; it was less hard but there was a departure in colour from the traditional product. The optimized condition for sauerkraut fermentation in terms of culture volume (ml), fermentation time (day) and salt concentration (g/100 g) was 30 ml, 28 days and 1 g/100 g, respectively. It was also observed that phenolics content was better in starter culture sauerkraut over the one traditionally prepared.


Assuntos
Brassica/química , Alimentos e Bebidas Fermentados/análise , Qualidade dos Alimentos , Alimentos em Conserva/análise , Lactobacillus paracasei/crescimento & desenvolvimento , Alimentos de Soja/microbiologia , Verduras/química , Antioxidantes/análise , Antioxidantes/metabolismo , Carga Bacteriana , Brassica/metabolismo , Brassica/microbiologia , Brassica/ultraestrutura , Fermentação , Alimentos e Bebidas Fermentados/economia , Alimentos e Bebidas Fermentados/microbiologia , Preferências Alimentares , Alimentos em Conserva/economia , Alimentos em Conserva/microbiologia , Indústria de Processamento de Alimentos/economia , Humanos , Concentração de Íons de Hidrogênio , Índia , Resíduos Industriais/análise , Resíduos Industriais/economia , Lactobacillus paracasei/isolamento & purificação , Lactobacillus paracasei/metabolismo , Microscopia Eletrônica de Varredura , Fenóis/análise , Fenóis/metabolismo , Pigmentos Biológicos/análise , Pigmentos Biológicos/biossíntese , Sensação , Cloreto de Sódio na Dieta/análise , Alimentos de Soja/economia , Fatores de Tempo , Verduras/metabolismo , Verduras/microbiologia , Verduras/ultraestrutura
7.
Food Res Int ; 93: 43-51, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28290279

RESUMO

Storage related changes in the cell wall composition potentially affect the texture of plant-based foods and the physiological effects of cell wall based dietary fiber components. Therefore, a detailed characterization of cell wall polysaccharides and lignins from broccoli stems was performed. Freshly harvested broccoli and broccoli stored at 20°C and 1°C for different periods of time were analyzed. Effects on dietary fiber contents, polysaccharide composition, and on lignin contents/composition were much more pronounced during storage at 20°C than at 1°C. During storage, insoluble dietary fiber contents of broccoli stems increased up to 13%. Storage related polysaccharide modifications include an increase of the portions of cellulose, xylans, and homogalacturonans and a decrease of the neutral pectic side-chains arabinans and galactans. Broccoli stem lignins are generally rich in guaiacyl units. Lignins from freshly harvested broccoli stems contain slightly larger amounts of p-hydroxyphenyl units than syringyl units. Syringyl units are predominantly incorporated into the lignin polymers during storage, resulting in increased acetyl bromide soluble lignin contents. NMR-based analysis of the interunit linkage types of broccoli stem lignins revealed comparably large portions of resinol structures for a guaiacyl rich lignin. Incorporation of syringyl units into the polymers over storage predominantly occurs through ß-O-4-linkages.


Assuntos
Brassica/química , Fibras na Dieta/análise , Armazenamento de Alimentos/métodos , Brassica/ultraestrutura , Configuração de Carboidratos , Parede Celular/química , Lignina/análise , Lignina/química , Espectroscopia de Ressonância Magnética , Caules de Planta/química , Caules de Planta/ultraestrutura , Polissacarídeos/análise , Polissacarídeos/química , Fatores de Tempo
8.
Plant Mol Biol ; 93(3): 313-326, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27909970

RESUMO

KEY MESSAGE: We identified and cloned the two precursors of miR158 and its target gene in Brassica campestris ssp. chinensis, which both had high relative expression in the inflorescences. Further study revealed that over-expression of miR158 caused reduced pollen varbility, which was caused by the degradation of pollen contents from the binucleate microspore stage. These results first suggest the role of miR158 in pollen development of Brassica campestris ssp. chinensis. MicroRNAs (miRNAs) play crucial roles in many important growth and development processes both in plants and animals by regulating the expression of their target genes via mRNA cleavage or translational repression. In this study, miR158, a Brassicaceae specific miRNA, was functionally characterized with regard to its role in pollen development of non-heading Chinese cabbage (Brassica campestris ssp. chinensis). Two family members of miR158 in B. campestris, namely bra-miR158a1 and bra-miR158a2, and their target gene bra027656, which encodes a pentatricopeptide repeat (PPR) containing protein, were identified. Then, qRT-PCR analysis and GUS-reporter system revealed that both bra-miR158 and its target gene had relatively high expression levels in the inflorescences. Further study revealed that over-expression of miR158 caused reduced pollen varbility and pollen germination ratio, and the degradation of pollen contents from the binucleate microspore stage was also found in those deformed pollen grains, which led to pollen shrinking and collapse in later pollen development stage. These results first shed light on the importance of miR158 in pollen development of Brassica campestris ssp. chinensis.


Assuntos
Brassica/genética , Regulação da Expressão Gênica de Plantas , MicroRNAs/metabolismo , Pólen/genética , Sequência de Bases , Brassica/crescimento & desenvolvimento , Brassica/ultraestrutura , Genes de Plantas , Germinação/genética , MicroRNAs/genética , Especificidade de Órgãos/genética , Plantas Geneticamente Modificadas , Pólen/crescimento & desenvolvimento , Pólen/ultraestrutura , Sobrevivência de Tecidos
9.
PLoS One ; 10(11): e0142202, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26536356

RESUMO

Cabbage belonging to Brassicaceae family is one of the most important vegetables cultivated worldwide. The economically important part of cabbage crop is head, formed by leaves which may be of splitting and non-splitting types. Cabbage varieties showing head splitting causes huge loss to the farmers and therefore finding the molecular and structural basis of splitting types would be helpful to breeders. To determine which anatomical characteristics were related to head-splitting in cabbage, we analyzed two contrasting cabbage lines and their offspring using a field emission scanning electron microscope. The inbred line "747" is an early head-splitting type, while the inbred line "748" is a head-splitting-resistant type. The petiole cells of "747" seems to be larger than those of "748" at maturity; however, there was no significant difference in petiole cell size at both pre-heading and maturity stages. The lower epidermis cells of "747" were larger than those of "748" at the pre-heading and maturity stages. "747" had thinner epidermis cell wall than "748" at maturity stage, however, there was no difference of the epidermis cell wall thickness in the two lines at the pre-heading stage. The head-splitting plants in the F1 and F2 population inherited the larger cell size and thinner cell walls of epidermis cells in the petiole. In the petiole cell walls of "747" and the F1 and F2 plants that formed splitting heads, the cellulose microfibrils were loose and had separated from each other. These findings verified that anomalous cellulose microfibrils, larger cell size and thinner-walled epidermis cells are important genetic factors that make cabbage heads prone to splitting.


Assuntos
Brassica/anatomia & histologia , Brassica/genética , Brassica/crescimento & desenvolvimento , Brassica/ultraestrutura , Parede Celular/ultraestrutura , Endogamia , Microscopia Eletrônica de Varredura
10.
Plant Mol Biol ; 87(6): 541-54, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25711971

RESUMO

The tapetum plays an important role in anther development by providing necessary enzymes and nutrients for pollen development. However, it is difficult to identify tapetum-specific genes on a large-scale because of the difficulty of separating tapetum cells from other anther tissues. Here, we reported the identification of tapetum-specific genes by comparing the gene expression patterns of four male sterile (MS) lines of Brassica oleracea. The abortive phenotypes of the four MS lines revealed different defects in tapetum and pollen development but normal anther wall development when observed by transmission electron microscopy. These tapetum displayed continuous defective characteristics throughout the anther developmental stages. The transcriptome from flower buds, covering all anther developmental stages, was analyzed and bioinformatics analyses exploring tapetum development-related genes were performed. We identified 1,005 genes differentially expressed in at least one of the MS lines and 104 were non-pollen expressed genes (NPGs). Most of the identified NPGs were tapetum-specific genes considering that anther walls were normally developed in all four MS lines. Among the 104 NPGs, 22 genes were previously reported as being involved in tapetum development. We further separated the expressed NPGs into different developmental stages based on the MS defects. The data obtained in this study are not only informative for research on tapetum development in B. oleracea, but are also useful for genetic pathway research in other related species.


Assuntos
Brassica/genética , Regulação da Expressão Gênica no Desenvolvimento , Infertilidade das Plantas/genética , Proteínas de Plantas/genética , Brassica/crescimento & desenvolvimento , Brassica/ultraestrutura , Flores/genética , Flores/crescimento & desenvolvimento , Flores/ultraestrutura , Expressão Gênica , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Hibridização In Situ , Microscopia Eletrônica de Transmissão , Anotação de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Especificidade de Órgãos , Fenótipo , Proteínas de Plantas/metabolismo , Pólen/genética , Pólen/crescimento & desenvolvimento , Pólen/ultraestrutura , RNA de Plantas/genética , Especificidade da Espécie
11.
Ecotoxicol Environ Saf ; 114: 179-89, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25638524

RESUMO

The beneficial role of selenium (Se) in alleviation of chromium (Cr)-induced oxidative stress is well established. However, little is known about the underlying mechanism. The impacts of exogenous Se (0.1mg/L) on Cr(1mg/L)-induced oxidative stress and antioxidant systems in leaves of cabbage (Brassica campestris L. ssp. Pekinensis) were investigated by using cellular and biochemical approaches. The results showed that supplementation of the medium with Se was effective in reducing Cr-induced increased levels of lipid peroxides and superoxide free radicals (O(-)2(·)), as well as increasing activities of superoxide dismutase (SOD) and peroxidase (POD). Meanwhile, 1mg/L Cr induced loss of plasma membrane integrity, growth inhibition, as well as ultrastructural changes of leaves were significantly reversed due to Se supplementation in the medium. In addition, Se application significantly altered the subcellular distribution of Cr which transported from mitochondria, nucleus and the cell-wall material to the soluble fraction and chloroplasts. However, Se application did no significant alteration of Cr effects on osmotic adjustment accumulating products. The study suggested that Se is able to protect leaves of cabbage against Cr toxicity by alleviation of Cr induced oxidative stress, and re-distribution of Cr in the subcellular of the leaf. Furthermore, free radicals, lipid peroxides, activity of SOD and POD, and subcellular distribution of Cr can be considered the efficient biomarkers to indicate the efficiency of Se to detoxification Cr.


Assuntos
Brassica/efeitos dos fármacos , Cromo/toxicidade , Poluentes Ambientais/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Selênio/farmacologia , Antioxidantes/metabolismo , Brassica/crescimento & desenvolvimento , Brassica/metabolismo , Brassica/ultraestrutura , Relação Dose-Resposta a Droga , Peróxidos Lipídicos/metabolismo , Peroxidase/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/ultraestrutura , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo
12.
Plant Sci ; 229: 66-75, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25443834

RESUMO

Brassica campestris pectate lyase-like 9 (BcPLL9) was previously identified as a differentially expressed gene both in buds during late pollen developmental stage and in pistils during fertilization in Chinese cabbage. To characterize the gene's function, antisense-RNA lines of BcPLL9 (bcpll9) were constructed in Chinese cabbage. Self- and cross-fertilization experiments harvested half seed yields when bcpll9 lines were used as pollen donors. In vivo and in vitro pollen germination assays showed that nearly half of the pollen tubes in bcpll9 were irregular with shorter length and uneven surface. Aniline blue staining identified abnormal accumulation of a specific bright blue unknown material in the bcpll9 pollen portion. Scanning electron microscopy observation verified the abnormal outthrust material to be near the pollen germinal furrows. Transmission electron microscopy observation revealed the internal endintine layer was overdeveloped and predominantly occupied the intine. This abnormally formed intine likely induced the wavy structure and growth arrest of the pollen tube in half of the bcpll9 pollen grains, which resulted in less seed yields. Collectively, this study presented a novel PLL gene that has an important function in B. campestris intine formation.


Assuntos
Brassica/enzimologia , Proteínas de Plantas/metabolismo , Pólen/crescimento & desenvolvimento , Polissacarídeo-Liases/metabolismo , Brassica/citologia , Brassica/genética , Brassica/ultraestrutura , Regulação da Expressão Gênica de Plantas , Germinação , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Pólen/metabolismo , Pólen/ultraestrutura , Tubo Polínico/crescimento & desenvolvimento , Polissacarídeo-Liases/genética , Sementes/genética
13.
Plant Reprod ; 27(4): 225-37, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25398253

RESUMO

Interspecific hybridizations promote gene transfer between species and play an important role in plant speciation and crop improvement. However, hybrid sterility that commonly found in the first generation of hybrids hinders the utilization of interspecific hybridization. The combination of divergent parental genomes can create extensive transcriptome variations, and to determine these gene expression alterations and their effects on hybrids, an interspecific Brassica hybrid of B. carinata × B. napus was generated. Scanning electron microscopy analysis indicated that some of the hybrid pollen grains were irregular in shape and exhibited abnormal exine patterns compared with those from the parents. Using the Illumina HiSeq 2000 platform, 39,598, 32,403 and 42,208 genes were identified in flower buds of B. carinata cv. W29, B. napus cv. Zhongshuang 11 and their hybrids, respectively. The differentially expressed genes were significantly enriched in pollen wall assembly, pollen exine formation, pollen development, pollen tube growth, pollination, gene transcription, macromolecule methylation and translation, which might be associated with impaired fertility in the F1 hybrid. These results will shed light on the mechanisms underlying the low fertility of the interspecific hybrids and expand our knowledge of interspecific hybridization.


Assuntos
Brassica/genética , Regulação da Expressão Gênica de Plantas , Genoma de Planta/genética , Transcriptoma , Brassica/fisiologia , Brassica/ultraestrutura , Brassica napus/genética , Brassica napus/fisiologia , Brassica napus/ultraestrutura , Quimera , Análise por Conglomerados , Flores/genética , Flores/fisiologia , Flores/ultraestrutura , Regulação da Expressão Gênica no Desenvolvimento , Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Hibridização Genética , Microscopia Eletrônica de Varredura , Anotação de Sequência Molecular , Pólen/genética , Pólen/fisiologia , Pólen/ultraestrutura , RNA de Plantas/química , RNA de Plantas/genética , Análise de Sequência de RNA
14.
Funct Integr Genomics ; 14(4): 731-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25147023

RESUMO

Cytoplasmic male sterility (CMS) is a common trait in higher plants, and several transcription factors regulate pollen development. Previously, we obtained a basic helix-loop-helix transcription factor, BcbHLHpol, via suppression subtractive hybridization in non-heading Chinese cabbage. However, the regulatory function of BcbHLHpol during anther and pollen development remains unclear. In this study, BcbHLHpol was cloned, and its tissue-specific expression profile was analyzed. The results of real-time polymerase chain reaction showed that BcbHLHpol was highly expressed in maintainer buds and that the transcripts of BcbHLHpol significantly decreased in the buds of pol CMS. A virus-induced gene silencing vector that targets BcbHLHpol was constructed and transformed into Brassica campestris plants to further explore the function of BcbHLHpol. Male sterility and short stature were observed in BcbHLHpol-silenced plants. The degradation of tapetal cells was inhibited in BcbHLHpol-silenced plants, and nutrients were insufficiently supplied to the microspore. These phenomena resulted in pollen abortion. This result indicates that BcbHLHpol functions as a positive regulator in pollen development. Yeast two-hybrid and bimolecular fluorescence complementation assays revealed that BcbHLHpol interacted with BcSKP1 in the nucleus. This finding suggests that BcbHLHpol and BcSKP1 are positive coordinating regulators of pollen development. Quantitative real-time PCR indicated that BcbHLHpol and BcSKP1 can be induced at low temperatures. Thus, we propose that BcbHLHpol is necessary for meiosis. This study provides insights into the regulatory functions of the BcbHLHpol network during anther development.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Brassica/crescimento & desenvolvimento , Brassica/metabolismo , Proteínas de Plantas/metabolismo , Pólen/crescimento & desenvolvimento , Pólen/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Brassica/genética , Brassica/ultraestrutura , Temperatura Baixa , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Fenótipo , Infertilidade das Plantas/genética , Proteínas de Plantas/genética , Vírus de Plantas/metabolismo , Pólen/citologia , Pólen/ultraestrutura , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Técnicas do Sistema de Duplo-Híbrido
15.
J Integr Plant Biol ; 56(11): 1095-105, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24773757

RESUMO

PECTATE LYASE-LIKE10 (PLL10) was previously identified as one of the differentially expressed genes both in microspores during the late pollen developmental stages and in pistils during the fertilization process in Chinese cabbage (Brassica campestris ssp. chinensis). Here, antisense-RNA was used to study the functions of BcPLL10 in Chinese cabbage. Abnormal pollen was identified in the transgenic lines (bcpll10-4, -5, and -6). In fertilization experiments, fewer seeds were harvested when the antisense-RNA lines were used as pollen donor. In vivo and in vitro pollen germination assays less germinated pollen tubes were observed in bcpll10 lines. Scanning electron microscopy observation verified that the tryphine materials were over accumulated around the pollen surface and sticked them together in bcpll10. Moreover, transmission electron microscopy observation revealed that the internal endintine was overdeveloped and predominantly occupied the intine, and disturbed the normal proportional distribution of the two layers in the non-germinal furrow region; and no obvious demarcation existed between them in the germinal furrow region in the bcpll10 pollen. Collectively, this study presented a novel PLL gene that played an important role during the pollen wall development in B. campestris, which may also possess potential importance for male sterility usage in agriculture.


Assuntos
Brassica/enzimologia , Brassica/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Pólen/crescimento & desenvolvimento , Polissacarídeo-Liases/metabolismo , Brassica/genética , Brassica/ultraestrutura , Regulação da Expressão Gênica de Plantas , Germinação , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Pólen/ultraestrutura , Polissacarídeo-Liases/genética , RNA Antissenso/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sementes/genética , Sementes/crescimento & desenvolvimento
16.
Plant Physiol ; 164(2): 710-20, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24351684

RESUMO

Leafy heads of cabbage (Brassica oleracea), Chinese cabbage (Brassica rapa), and lettuce (Lactuca sativa) are composed of extremely incurved leaves. The shape of these heads often dictates the quality, and thus the commercial value, of these crops. Using quantitative trait locus mapping of head traits within a population of 150 recombinant inbred lines of Chinese cabbage, we investigated the relationship between expression levels of microRNA-targeted Brassica rapa ssp. pekinensis TEOSINTE BRANCHED1, cycloidea, and PCF transcription factor4 (BrpTCP4) genes and head shape. Here, we demonstrate that a cylindrical head shape is associated with relatively low BrpTCP4-1 expression, whereas a round head shape is associated with high BrpTCP4-1 expression. In the round-type Chinese cabbage, microRNA319 (miR319) accumulation and BrpTCP4-1 expression decrease from the apical to central regions of leaves. Overexpression of BrpMIR319a2 reduced the expression levels of BrpTCP4 and resulted in an even distribution of BrpTCP4 transcripts within all leaf regions. Changes in temporal and spatial patterns of BrpTCP4 expression appear to be associated with excess growth of both apical and interveinal regions, straightened leaf tips, and a transition from the round to the cylindrical head shape. These results suggest that the miR319a-targeted BrpTCP gene regulates the round shape of leafy heads via differential cell division arrest in leaf regions. Therefore, the manipulation of miR319a and BrpTCP4 genes is a potentially important tool for use in the genetic improvement of head shape in these crops.


Assuntos
Brassica/anatomia & histologia , Brassica/genética , Divisão Celular/genética , Genes de Plantas/genética , MicroRNAs/genética , Folhas de Planta/citologia , Folhas de Planta/genética , Sequência de Bases , Brassica/citologia , Brassica/ultraestrutura , Tamanho Celular , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Endogamia , MicroRNAs/metabolismo , Dados de Sequência Molecular , Tamanho do Órgão , Fenótipo , Filogenia , Epiderme Vegetal/citologia , Folhas de Planta/anatomia & histologia , Folhas de Planta/ultraestrutura , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Recombinação Genética/genética , Fatores de Tempo
17.
J Plant Res ; 126(6): 823-32, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23887833

RESUMO

The Orange (Or) gene is a gene mutation that can increase carotenoid content in plant tissues normally devoid of pigments. It affects plastid division and is involved in the differentiation of proplastids or non-colored plastids into chromoplasts. In this study, the de-etiolation process of the wild type (WT) cauliflower (Brassica oleracea L. var. botrytis) and Or mutant seedlings was investigated. We analyzed pigment content, plastid development, transcript abundance and protein levels of genes involved in the de-etiolation process. The results showed that Or can increase the carotenoid content in green tissues, although not as effectively as in non-green tissues, and this effect might be caused by the changes in biosynthetic pathway genes at both transcriptional and post-transcriptional levels. There was no significant difference in the plastid development process between the two lines. However, the increased content of antheraxanthin and anthocyanin, and higher expression levels of violaxanthin de-epoxidase gene (VDE) suggested a stress situation leading to photoinhibition and enhanced photoprotection in the Or mutant. The up-regulated expression levels of the reactive oxygen species (ROS)-induced genes, ZAT10 for salt tolerance zinc finger protein and ASCORBATE PEROXIDASE2 (APX2), suggested the existence of photo-oxidative stress in the Or mutant. In summary, abovementioned findings provide additional insight into the functions of the Or gene in different tissues and at different developmental stages.


Assuntos
Brassica/fisiologia , Regulação da Expressão Gênica de Plantas , Pigmentos Biológicos/metabolismo , Proteínas de Plantas/genética , Espécies Reativas de Oxigênio/metabolismo , Antocianinas/metabolismo , Brassica/genética , Brassica/efeitos da radiação , Brassica/ultraestrutura , Carotenoides/metabolismo , Clorofila/metabolismo , Cloroplastos/metabolismo , Cloroplastos/ultraestrutura , Cotilédone/genética , Cotilédone/fisiologia , Cotilédone/efeitos da radiação , Cotilédone/ultraestrutura , Estiolamento , Luz , Mutação , Especificidade de Órgãos , Estresse Oxidativo , Folhas de Planta/genética , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Folhas de Planta/ultraestrutura , Proteínas de Plantas/metabolismo , Plastídeos/metabolismo , Plastídeos/ultraestrutura , Plântula/genética , Plântula/fisiologia , Plântula/efeitos da radiação , Plântula/ultraestrutura , Regulação para Cima
18.
J Agric Food Chem ; 61(20): 4715-22, 2013 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-23621278

RESUMO

Differential centrifugation and synchrotron radiation X-ray fluorescence spectroscopy (SRXRF) microprobe were used to study the distribution of the elements in tissue cross sections of pakchoi ( Brassica chinensis L.) under stress of elevated Pb and Cr. Subcellular fractionation of the different tissues grown in a nutrient solution containing 200 mg L(-1) Pb or 5 mg L(-1) Cr showed that 86.7 and 76.3% of the Pb that accumulated in the roots and shoots, respectively, was contained in the cell wall and vacuoles in those areas. Whereas 75.0% of the Cr that accumulated in the root was contained in the cell wall, 63.1% of the Cr that accumulated in the shoot was found in the vacuoles and cell wall. SRXRF analysis revealed that, when pakchoi seedlings were placed under excess Pb stress, the Pb, Ca, Cu, and Zn were concentrated in the cortex and vascular bundle of the root and mixed Fe-Mn plaques were seen on the surface of the pakchoi root. In the Cr treatment group, Cr, Ca, Mn, and Zn were mainly located in the cortex of the root, whereas in the stem, only Ca, Cu, and Zn were detected at higher levels in the cortex area. Thus, this study provides evidence that, in response to Pb and Cr stress, pakchoi uses cell walls and vacuoles to reduce the transport of these heavy metals through the plant, as well as restrict transport from the root to the stem.


Assuntos
Brassica/ultraestrutura , Cromo/administração & dosagem , Chumbo/administração & dosagem , Metais/análise , Frações Subcelulares/química , Brassica/efeitos dos fármacos , Brassica/crescimento & desenvolvimento , Cálcio/análise , Parede Celular/química , Cromo/análise , Cobre/análise , Manganês/análise , Raízes de Plantas/química , Raízes de Plantas/ultraestrutura , Brotos de Planta/química , Brotos de Planta/ultraestrutura , Espectrometria por Raios X , Estresse Fisiológico , Vacúolos/química , Zinco/análise
19.
Genet Mol Res ; 11(4): 4145-56, 2012 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-23079967

RESUMO

Cytoplasmic male sterile line RC(7) of Chinese cabbage produces mature anthers without pollen. To understand the mechanisms involved, we examined the ultrastructural changes during development of the microspores. Development of microspores was not affected at the early tetrad stage. During the ring-vacuolated period, some large vacuoles appeared in the tapetum cells, making them larger, extending to the anther sac center during the monocyte period. At the same time, the tapetum degenerated as the microspores aborted, resulting in pollen-deficient anthers. As a result, the locules collapsed and the anthers shriveled. The callose was degraded in the pollen walls; abnormal deposits of electrodense material gave rise to irregular spike-shaped structures, rather than the characteristic rod-like shape of the B7 bacula. The internal intine wall of RC(7) was thinner than that of the B7 type. At the mitosis I microspore stage, the tapetum cells contained multiple plastids, with numerous small spherical plastoglobuli, and lipid bodies. Based on these observations, we suggest that RC(7) abortion may be due to mutated genes that normally regulate development of the pollen wall and cell walls in the RC(7) line.


Assuntos
Brassica/ultraestrutura , Pólen/ultraestrutura , Apoptose , Brassica/genética , Parede Celular/ultraestrutura , Citoplasma , Flores/genética , Flores/ultraestrutura , Microscopia Eletrônica de Transmissão , Infertilidade das Plantas , Pólen/genética
20.
Plant J ; 71(3): 503-16, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22679928

RESUMO

Interploidy crosses fail in many plant species due to abnormalities in endosperm development. In the inbreeding species Arabidopsis thaliana, both paternal and maternal excess interploidy crosses usually result in viable seed that exhibit parent-of-origin effects on endosperm development and final seed size. Paternal excess crosses result in extended proliferation of the endosperm and larger seeds, while conversely maternal excess crosses result in early endosperm cellularisation and smaller seeds. Investigations into the effect of parental gene dosage on seed development have revealed that MADS box transcription factors, particularly the AGAMOUS-like family, play important roles in controlling endosperm proliferation. The important crop genus Brassica contains self-incompatible outbreeding species and has a larger and more complex genome than the closely related Arabidopsis. Here we show that although Brassica oleracea displays strong parent-of-origin effects on seed development, triploid block due to lethal disruption of endosperm development was restricted to paternal excess, with maternal excess crosses yielding viable seed. In addition, transcriptome analyses of Brassica homologues of Arabidopsis genes linked to parent-of-origin effects revealed conservation of some mechanisms controlling aspects endosperm behaviour in the two species. However, there were also differences that may explain the failure of the paternal excess cross in B. oleracea.


Assuntos
Brassica/genética , Endosperma/genética , Dosagem de Genes/genética , Genoma de Planta/genética , Impressão Genômica/genética , Proteínas de Domínio MADS/genética , Arabidopsis/embriologia , Arabidopsis/genética , Arabidopsis/ultraestrutura , Brassica/embriologia , Brassica/ultraestrutura , Cruzamentos Genéticos , Endosperma/embriologia , Endosperma/ultraestrutura , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/genética , Modelos Moleculares , Fenótipo , Proteínas de Plantas/genética , Plântula/embriologia , Plântula/genética , Plântula/ultraestrutura , Sementes/embriologia , Sementes/genética , Sementes/ultraestrutura , Fatores de Transcrição/genética , Triploidia
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