RESUMEN
The area of the Garda Lake within the Trentino province (north of Italy) is the northernmost part of Europe where the Mediterranean species Olea europaea L. is traditionally cultivated. 'Casaliva' is claimed as the main variety traditionally grown in the Garda Trentino area (GT) from which a world renowned niche extra virgin olive oil is produced. Since a dominant presence of 'Casaliva' would link the fruit set success and yield to a self-pollination compatibility system, a deep genetic survey of the olive tree population in the GT has been performed with the aim of establishing the actual varietal composition and of understanding from which pollen donor the 'Casaliva' olives originate. Forty-four different genetic profiles were observed among the 205 leaf samples collected from 106 ancient trees through the analysis of 20 nuclear microsatellite markers. The varietal composition in modern orchards was also explored and the vast majority of the additional 151 trees analyzed showed the same genotype as the ancient accessions of 'Casaliva'. The results support the long historical link of 'Casaliva' with the GT and, besides a high varietal homogeneity, they also revealed the presence of olive genetic resources essential to fruit production. In fact, the parentage analysis of 550 embryos from drupes of 'Casaliva' evidenced that a cross-fertilization system is favored and a list of candidate cultivars most suitable as local pollinizers of 'Casaliva' was identified.
Asunto(s)
Frutas/genética , Genotipo , Repeticiones de Microsatélite , Olea/genética , Árboles/genética , Frutas/embriología , Olea/embriología , PolinizaciónRESUMEN
In this study, third-generation full-length (FL) transcriptome sequencing was performed of loquat using single-molecule real-time(SMRT) sequencing from the pooled cDNA of embryos of young loquat fruit under different low temperatures (three biological replicates for treatments of 1°C, -1°C, and -3°C, for 12 h or 24 h) and the control group(three biological replicates for treatments of room temperature), Illumina sequencing was used to correct FL transcriptome sequences. A total of 3 PacBio Iso-Seq libraries (1-2 kb, 2-3 kb and 3-6 kb) and 21 Illumina transcriptome libraries were constructed, a total of 13.41 Gb of clean reads were generated, which included 215,636 reads of insert (ROIs) and 121,654 FL, non-chimaric (FLNC) reads. Transcript clustering analysis of the FLNC reads revealed 76,586 consensus isoforms, and a total of 12,520 high-quality transcript sequences corrected with non-FL sequences were used for subsequent analysis. After the redundant reads were removed, 38,435 transcripts were obtained. A total of 27,905 coding DNA sequences (CDSs) were identified, and 407 long non-coding RNAs (lncRNAs) were ultimately predicted. Additionally, 24,832 simple sequence repeats (SSRs) were identified, and a total of 1,295 alternative splicing (AS) events were predicted. Furthermore, 37,993 transcripts were annotated in eight functional databases. This is the first study to perform SMRT sequencing of the FL transcriptome of loquat. The obtained transcriptomic data are conducive for further exploration of the mechanism of loquat freezing injury and thus serve as an important theoretical basis for generating new loquat material and for identifying new ways to improve loquat cold resistance.
Asunto(s)
Eriobotrya/genética , Empalme Alternativo , Frío , Respuesta al Choque por Frío/genética , Bases de Datos Genéticas , Eriobotrya/embriología , Frutas/embriología , Frutas/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Repeticiones de Microsatélite , Proteínas de Plantas/genética , ARN Largo no Codificante/genética , ARN de Planta/genética , Análisis de Secuencia de ARN , Factores de Transcripción/genética , TranscriptomaRESUMEN
The dead organs enclosing embryos (DOEEs) emerge as central components of the dispersal unit (DU) capable for long-term storage of active proteins and other substances that affect seed performance and fate. We studied the effect of maternal environment (salt and salt+heat) on progeny DU (dry indehiscent fruit) focusing on pericarp properties of Anastatica hierochuntica. Stressed plants displayed increased seed abortion and low level and rate of germination. Hydrated pericarps released antimicrobial factors and allelopathic substances that inhibit germination of heterologous species. Proteome analysis of dead pericarps revealed hundreds of proteins, among them nucleases, chitinases and proteins involved in reactive oxygen species detoxification and cell wall modification. Salt treatment altered the composition and level of proteins stored in the pericarp. We observed changes in protein profile released from seeds of salt-treated plants with a notable increase in a small anti-fungal protein, defensin. The levels of phytohormones including IAA, ABA and salicylic acid were reduced in dead pericarps of stressed plants. The data presented here highlighted the predominant effects of maternal environment on progeny DUs of the desert plant A. hierochuntica, particularly on pericarp properties, which in turn might affect seed performance and fate, soil fertility and consequently plant biodiversity.
Asunto(s)
Brassicaceae , Frutas , Brassicaceae/embriología , Brassicaceae/metabolismo , Defensinas/metabolismo , Frutas/embriología , Frutas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Proteoma/análisis , Semillas/metabolismo , Estrés FisiológicoRESUMEN
The gynoecium, the female reproductive part of the flower, is key for plant sexual reproduction. During its development, inner tissues such as the septum and the transmitting tract tissue, important for pollen germination and guidance, are formed. In Arabidopsis, several transcription factors are known to be involved in the development of these tissues. One of them is NO TRANSMITTING TRACT (NTT), essential for transmitting tract formation. We found that the NTT protein can interact with several gynoecium-related transcription factors, including several MADS-box proteins, such as SEEDSTICK (STK), known to specify ovule identity. Evidence suggests that NTT and STK control enzyme and transporter-encoding genes involved in cell wall polysaccharide and lipid distribution in gynoecial medial domain cells. The results indicate that the simultaneous loss of NTT and STK activity affects polysaccharide and lipid deposition and septum fusion, and delays entry of septum cells to their normal degradation program. Furthermore, we identified KAWAK, a direct target of NTT and STK, which is required for the correct formation of fruits in Arabidopsis These findings position NTT and STK as important factors in determining reproductive competence.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/embriología , Frutas/embriología , Proteínas de Dominio MADS/metabolismo , Factores de Transcripción/metabolismo , Arabidopsis/genética , Arabidopsis/ultraestructura , Proteínas de Arabidopsis/genética , Pared Celular/genética , Pared Celular/metabolismo , Frutas/genética , Frutas/ultraestructura , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Redes Reguladoras de Genes , Metabolismo de los Lípidos/genética , Proteínas de Dominio MADS/genética , Mananos/metabolismo , Meristema/metabolismo , Mutación/genética , Tubo Polínico/embriología , Tubo Polínico/metabolismo , Tubo Polínico/ultraestructura , Unión Proteica , Reproducción , Transcripción GenéticaRESUMEN
KEY MESSAGE: We show that the calcium sensor, CML39, is important in various developmental processes from seeds to mature plants. This study bridges previous work on CML39 as a stress-induced gene and highlights the importance of calcium signalling in plant development. In addition to the evolutionarily-conserved Ca2+ sensor, calmodulin (CaM), plants possess a large family of CaM-related proteins (CMLs). Using a cml39 loss-of-function mutant, we investigated the roles of CML39 in Arabidopsis and discovered a range of phenotypes across developmental stages and in different tissues. In mature plants, loss of CML39 results in shorter siliques, reduced seed number per silique, and reduced number of ovules per pistil. We also observed changes in seed development, germination, and seed coat properties in cml39 mutants in comparison to wild-type plants. Using radicle emergence as a measure of germination, cml39 mutants showed more rapid germination than wild-type plants. In marked contrast to wild-type seeds, the germination of developing, immature cml39 seeds was not sensitive to cold-stratification. In addition, germination of cml39 seeds was less sensitive than wild-type to inhibition by ABA or by treatments that impaired gibberellic acid biosynthesis. Tetrazolium red staining indicated that the seed-coat permeability of cml39 seeds is greater than that of wild-type seeds. RNA sequencing analysis of cml39 seedlings suggests that changes in chromatin modification may underlie some of the phenotypes associated with cml39 mutants, consistent with previous reports that orthologs of CML39 participate in gene silencing. Aberrant ectopic expression of transcripts for seed storage proteins in 7-day old cml39 seedlings was observed, suggesting mis-regulation of early developmental programs. Collectively, our data support a model where CML39 serves as an important Ca2+ sensor during ovule and seed development, as well as during germination and seedling establishment.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/embriología , Arabidopsis/metabolismo , Calmodulina/metabolismo , Frutas/embriología , Germinación , Semillas/embriología , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Calmodulina/genética , Flores/embriología , Flores/genética , Frutas/genética , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Germinación/genética , Giberelinas/metabolismo , Mutación/genética , Permeabilidad , Latencia en las Plantas , Regiones Promotoras Genéticas/genética , Semillas/genética , Transcripción GenéticaRESUMEN
The plant hormone auxin is a major regulator of plant development and response to environmental cues. Auxin plays a particularly central role in flower development, but the knowledge of its role of flower development in crop plants with fleshy fruits, such as tomato, is still scarce. Mutations in the Aux/IAA gene ENTIRE/Indole Acetic Acid 9 (E/IAA9) lead to the precocious development of young gynoecia into parthenocarpic fruits. Here, we compared the distribution of the auxin response sensor DR5::VENUS and the auxin efflux transporter PIN1 between the wild type and entire during successive stages of flower and fruit development. Up-regulation of the DR5::VENUS signal in the shoot apical meristem (SAM) was observed upon the transition to flowering, implicating a possible role for auxin in the transition from a vegetative SAM into an inflorescence meristem. DR5::VENUS was expressed in all initiating floral organs. Additionally, DR5::VENUS was highly expressed during gametogenesis, in both male and female organs, and in the developing seeds during embryogenesis. DR5::VENUS is expressed in functional cell layers such as the anther stomium and tapetum, suggesting that auxin plays a role in flower organ development and function. The entire mutation affected DR5::VENUS expression patterns during inflorescence formation and flower organ development, which correlated with phenotypic alterations. We also show dynamic distribution and localization of the auxin transporter PIN1 during flower and fruit organ development. These results emphasize the dynamic auxin response in inflorescence and flower development and suggest multiple roles of auxin in these processes.
Asunto(s)
Flores/embriología , Genes de Plantas , Ácidos Indolacéticos/metabolismo , Mutación/genética , Solanum lycopersicum/embriología , Solanum lycopersicum/genética , Transporte Biológico , Flores/genética , Fluorescencia , Frutas/embriología , Organogénesis , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , ReproducciónRESUMEN
Cells respond to many signals with a limited number of signaling components. Heterotrimeric G proteins and MAPK cascades are universally used by eukaryotic cells to transduce signals in various developmental processes or stress responses by activating different effectors. MAPK cascade is integrated with G proteins by scaffold protein during plant immunity. However, the molecular relationship between G proteins and MAPK modules in plant development is still unclear. In this study, we demonstrate that Arabidopsis Gß protein AGB1 interacts with MPK3 and 6, MKK4 and 5, as well as the regulatory domains of YODA (YDA), the upstream MEKK of MKK4/5. Remarkably, YDA interacts with the plasma membrane associated SHORT SUSPENSOR (SSP) through its N- and C-terminal region in vitro and in vivo. Additionally, genetic analysis shows that AGB1 functions together with MPK3/6 signaling cascade during the asymmetric division of the zygote. These data indicate that Gß may function likely as a scaffold, through direct physical interaction with the components of the MPK signaling module in plant development. Our results provide new insights into the molecular functions of G protein and will advance the understanding of the complex mechanism of kinase signaling cascades.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/embriología , Arabidopsis/enzimología , Subunidades beta de la Proteína de Unión al GTP/metabolismo , Sistema de Señalización de MAP Quinasas , Cigoto/crecimiento & desarrollo , Cigoto/metabolismo , Arabidopsis/anatomía & histología , Arabidopsis/genética , Proteínas de Arabidopsis/química , Fluorescencia , Frutas/embriología , Subunidades beta de la Proteína de Unión al GTP/química , Fenotipo , Unión Proteica , Dominios Proteicos , Subunidades de Proteína/metabolismoRESUMEN
Carotenoid dioxygenases, including 9-cis-epoxycarotenoid dioxygenases (NCEDs) and carotenoid cleavage dioxygenases (CCDs), can selectively cleave carotenoids into various apocarotenoid products that play important roles in fleshy fruit development and abiotic stress response. In this study, we identified 12 carotenoid dioxygenase genes in diploid strawberry Fragaria vesca, and explored their evolution with orthologous genes from nine other species. Phylogenetic analyses suggested that the NCED and CCDL groups moderately expanded during their evolution, whereas gene numbers of the CCD1, CCD4, CCD7, and CCD8 groups maintained conserved. We characterized the expression profiles of FveNCED and FveCCD genes during flower and fruit development, and in response to several abiotic stresses. FveNCED1 expression positively responded to osmotic, cold, and heat stresses, whereas FveNCED2 was only induced under cold stress. In contrast, FveNCED2 was the unique gene highly and continuously increasing in receptacle during fruit ripening, which co-occurred with the increase in endogenous abscisic acid (ABA) content previously reported in octoploid strawberry. The differential expression patterns suggested that FveNCED1 and FveNCED2 were key genes for ABA biosynthesis in abiotic stress responses and fruit ripening, respectively. FveCCD1 exhibited the highest expression in most stages of flower and fruit development, while the other FveCCDs were expressed in a subset of stages and tissues. Our study suggests distinct functions of FveNCED and FveCCD genes in fruit development and stress responses and lays a foundation for future study to understand the roles of these genes and their metabolites, including ABA and other apocarotenoid products, in the growth and development of strawberry.
Asunto(s)
Dioxigenasas/genética , Fragaria , Frutas/embriología , Proteínas de Plantas/genética , Carotenoides/metabolismo , Fragaria/enzimología , Fragaria/genética , Fragaria/crecimiento & desarrollo , Frutas/genética , Regulación de la Expresión Génica de las Plantas , Oxigenasas/genética , FilogeniaRESUMEN
Understanding how plants cope with changing habitats is a timely and important topic in plant research. Phenotypic plasticity describes the capability of a genotype to produce different phenotypes when exposed to different environmental conditions. In contrast, the constant production of a set of distinct phenotypes by one genotype mediates bet hedging, a strategy that reduces the temporal variance in fitness at the expense of a lowered arithmetic mean fitness. Both phenomena are thought to represent important adaptation strategies to unstable environments. However, little is known about the underlying mechanisms of these phenomena, partly due to the lack of suitable model systems. We used phylogenetic and comparative analyses of fruit and seed anatomy, biomechanics, physiology, and environmental responses to study fruit and seed heteromorphism, a typical morphological basis of a bet-hedging strategy of plants, in the annual Brassicaceae species Aethionema arabicum Our results indicate that heteromorphism evolved twice within the Aethionemeae, including once for the monophyletic annual Aethionema clade. The dimorphism of Ae. arabicum is associated with several anatomic, biomechanical, gene expression, and physiological differences between the fruit and seed morphs. However, fruit ratios and numbers change in response to different environmental conditions. Therefore, the life-history strategy of Ae. arabicum appears to be a blend of bet hedging and plasticity. Together with the available genomic resources, our results pave the way to use this species in future studies intended to unravel the molecular control of heteromorphism and plasticity.
Asunto(s)
Brassicaceae/embriología , Frutas/embriología , Semillas/embriología , Brassicaceae/anatomía & histología , Brassicaceae/genética , Brassicaceae/ultraestructura , Regulación hacia Abajo/genética , Frutas/genética , Frutas/ultraestructura , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Genes del Desarrollo , Genes de Plantas , Germinación/genética , Modelos Biológicos , Fenotipo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Dispersión de Semillas , Semillas/genética , Semillas/ultraestructura , Homología de Secuencia de AminoácidoRESUMEN
The transcriptomes of five pear cultivars, 'Hosui' (P. pyrifolia), 'Yali' (P. bretschneideri), 'Kuerlexiangli' (P. sinkiangensis), 'Nanguoli' (P. ussuriensis), and 'Starkrimson' (P. communis) were sequenced at seven key fruit developmental stages, from fruit setting to maturation and fruit senescence after harvesting. In total, 33,136 genes that could be mapped by reads, were analyzed. Most gene expression cluster models showed a steadily decreasing trend. Gene expression patterns had obvious differences according to maturity type, that is, post-ripening cultivars were still vigorous at maturity, and showed a higher proportion of up-regulated genes; non post-ripening cultivars had a gradually decreasing tendency during fruit maturation. Meanwhile, differentially expressed genes related to fruit quality and development, such as stone cells, sugar, acid and hormones, were identified. Co-expression analysis revealed that several ethylene synthesis genes and polyphenoloxidase-related genes interacted with each other directly, and an indirect relationship was reflected between ethylene synthesis genes and ethylene response genes. In addition, the highly diverse SNPs represented the great differences between oriental and occidental pears. Understanding how RNA-seq based gene-expression patterns and differential gene expression contribute to fruit quality allows us to build models for gene-expression for fruit development of Pyrus species.
Asunto(s)
Frutas/embriología , Regulación de la Expresión Génica de las Plantas/genética , Pyrus/genética , Etilenos/biosíntesis , Frutas/genética , Expresión Génica/genética , Perfilación de la Expresión Génica , Proteínas de Plantas/metabolismo , Polimorfismo de Nucleótido Simple/genética , Pyrus/embriología , Receptores de Superficie Celular/metabolismo , Transcriptoma/genéticaRESUMEN
The role of polygalacturonase (PG) in the development, ripening, and softening of fruit from two strawberry cultivars with different flesh firmness and softening characteristics was compared. Changes in PG activity and gene expression during development, ripening and softening were measured. The PG genes from each cultivar were cloned and analyzed, and were classified with other PG genes using phylogenetic analysis. In Toyonoka fruit, PG activity increased gradually, reaching a peak during the pink stage, and remained at this level during post-harvest softening. Changes in PG gene expression were consistent with PG activity in these softer fruits. In the firmer Sweet Charlie fruits, PG activity was detected during the initial development stage, reaching a peak at the white stage, thereafter decreasing gradually with ripening and remaining at this lower level throughout softening. Changes in PG gene expression and PG activity were not consistent in these fruit. For both Toyonoka and Sweet Charlie PG genes (FaTPG and FaSCPG, respectively), the open reading frame was 1218 bp, encoding 405 amino acids. Five different nucleotide sites were observed between the two sequences, leading to two amino acid sequence mutations. FaTPG, FaSCPG, and PG genes from the Fragaria vesca genome were classified into three clades using phylogenetic analysis. The clade containing PG genes involved in fruit softening had functional similarity but there were no functional differences between FaTPG and FaSCPG. Differences in PG activity, gene sequence, and gene expression may have led to different roles of PG during ripening and softening in strawberries with different textures.
Asunto(s)
Fragaria/enzimología , Frutas/embriología , Poligalacturonasa/metabolismo , Fragaria/genética , Fragaria/fisiología , Frutas/genética , Frutas/fisiología , Regulación de la Expresión Génica de las Plantas/genéticaRESUMEN
Irradiated pollen technique is the most successful haploidization technique within Cucurbitaceae. After harvesting of fruits pollinated with irradiated pollen, classical method called as "inspecting the seeds one by one" is used to find haploid embryos in the seeds. In this study, different methods were used to extract the embryos more easily, quickly, economically, and effectively. "Inspecting the seeds one by one" was used as control treatment. Other four methods tested were "sowing seeds direct nutrient media," "inspecting seeds in the light source," "floating seeds on liquid media," and "floating seeds on liquid media after surface sterilization." Y2 and Y3 melon genotypes selected from the third backcross population of Yuva were used as plant material. Results of this study show that there is no statistically significant difference among methods "inspecting the seeds one by one," "sowing seeds direct CP nutrient media," and "inspecting seeds in the light source," although the average number of embryos per fruit is slightly different. No embryo production was obtained from liquid culture because of infection. When considered together with labor costs and time required for embryo rescue, the best methods were "sowing seeds directly in the CP nutrient media" and "inspecting seeds in the light source."
Asunto(s)
Cucumis melo/embriología , Frutas/economía , Frutas/embriología , Haploidia , Polen/embriología , Técnicas de Cultivo de Tejidos/economía , Técnicas de Cultivo de Tejidos/métodos , Polen/efectos de la radiación , Polinización/efectos de la radiación , Semillas , TurquíaRESUMEN
Common juniper (Juniperus communis L.) populations in northwest European lowlands are currently declining in size and number. An important cause of this decline is a lack of natural regeneration. Low seed viability seems to be one of the main bottlenecks in this process. Previous research revealed a negative relation between seed viability and both temperature and nitrogen deposition. Additionally, the seeds of common juniper have a variable ripening time, which possibly influences seed viability. However, the underlying mechanisms remain unresolved. In order to elucidate this puzzle, it is important to understand in which phases of seed production the main defects are situated, together with the influence of ripening time. In this study, we compared seed viability of populations with and without successful recruitment. We examined three seed phases: (i) gamete development; (ii) fertilisation and early-embryo development; and (iii) late-embryo development. After the first two phases, we found no difference in the percentage viable seeds between populations with or without recruitment. After late-embryo development, populations without recruitment showed a significantly lower percentage of viable seeds. These results suggest that late-embryo development is a bottleneck in seed development. However, the complex interaction between seed viability and ripening time suggest that the causes should be in the second seed phase, as the accelerated development of male and female gametophytes may disturb the male-female synchrony for successful mating.
Asunto(s)
Juniperus/crecimiento & desarrollo , Polinización , Semillas/crecimiento & desarrollo , Animales , Clima , Fertilización , Frutas/embriología , Frutas/crecimiento & desarrollo , Frutas/parasitología , Frutas/fisiología , Geografía , Células Germinativas de las Plantas , Germinación , Himenópteros/fisiología , Juniperus/embriología , Juniperus/parasitología , Juniperus/fisiología , Ácaros/fisiología , Nitrógeno/metabolismo , Enfermedades de las Plantas/parasitología , Polen/embriología , Polen/crecimiento & desarrollo , Polen/parasitología , Polen/fisiología , Semillas/embriología , Semillas/parasitología , Semillas/fisiología , Temperatura , Factores de Tiempo , ÁrbolesRESUMEN
Seedlessness is an important economic trait of lemon. Understanding the cellular and molecular mechanisms of seedlessness in 'Xiangshui' lemon requires detailed data on pollen and embryo sac fertility, embryo development and compatibility mechanisms governing self- and cross-pollination. The results of the current study indicate that the fertility of pollen and mature embryo sac remains normal. When flowers were self- or cross-pollinated, pollen grains of 'Xiangshui' were able to germinate on the stigma. In the case of self-pollination, pollen tubes became twisted, tube tips enlarged and tubes ruptured in the bottom of stigma. Following cross-pollination, tubes were able to grow normally in the style and ovary and enter the embryo sac, where double fertilization took place. Embryonic development resulting from cross-pollination was normal. After cross-pollination, the zygote began to divide at 2 weeks post-pollination, with early globular embryos observed after 3 weeks, globular and heart-shaped embryos at 4 weeks, torpedo-shaped embryos at 5 weeks, cotyledonary embryos at 6 weeks and thereafter germinable seeds. After self-pollination, however, ovules began to abort at 2 weeks post-pollination, with ovules disappearing at 5 weeks, ultimately producing seedless fruits. Emasculated unpollinated flowers also developed into seedless fruits, indicating that seedlessness contributes to parthenocarpy. However, gametophytic self-incompatibility has a major role in seedlessness in 'Xiangshui' lemon by blocking fertilization at the bottom of the stigma.
Asunto(s)
Citrus/fisiología , Polen/fisiología , Polinización/fisiología , Autoincompatibilidad en las Plantas con Flores/fisiología , Supervivencia Celular , Citrus/citología , Citrus/embriología , Citrus/genética , Cruzamientos Genéticos , Flores/citología , Flores/embriología , Flores/genética , Flores/fisiología , Frutas/citología , Frutas/embriología , Frutas/genética , Frutas/fisiología , Meiosis , Óvulo Vegetal/citología , Óvulo Vegetal/embriología , Óvulo Vegetal/genética , Óvulo Vegetal/fisiología , Polen/citología , Polen/embriología , Polen/genética , Semillas/citología , Semillas/embriología , Semillas/genética , Semillas/fisiología , AutofecundaciónRESUMEN
BACKGROUND AND AIMS: Cytokinins are a major group of plant hormones and are associated with various developmental processes. Developing caryopses of maize have high levels of cytokinins, but little is known about their spatial and temporal distribution. The localization and quantification of cytokinins was investigated in maize (Zea mays) caryopsis from 0 to 28 d after pollination together with the expression and localization of isopentenyltransferase ZmIPT1 involved in cytokinin biosynthesis and ZmCNGT, the gene putatively involved in N9-glucosylation. METHODS: Biochemical, cellular and molecular approaches resolved the overall cytokinin profiles, and several gene expression assays were used for two critical genes to assess cytokinin cell-specific biosynthesis and conversion to the biologically inactive form. Cytokinins were immunolocalized for the first time in maize caryopses. KEY RESULTS: During the period 0-28 d after pollination (DAP): (1) large quantities of cytokinins were detected in the maternal pedicel region relative to the filial tissues during the early stages after fertilization; (2) unpollinated ovules did not accumulate cytokinins; (3) the maternal nucellar region showed little or no cytokinin signal; (4) the highest cytokinin concentrations in filial endosperm and embryo were detected at 12 DAP, predominantly zeatin riboside and zeatin-9-glucoside, respectively; and (5) a strong cytokinin immuno-signal was detected in specific cell types in the pedicel, endosperm and embryo. CONCLUSIONS: The cytokinins of developing maize caryopsis may originate from both local syntheses as well as by transport. High levels of fertilization-dependent cytokinins in the pedicel suggest filial control on metabolism in the maternal tissue; they may also trigger developmental programmed cell death in the pedicel.
Asunto(s)
Citocininas/biosíntesis , Frutas/embriología , Frutas/metabolismo , Zea mays/anatomía & histología , Zea mays/metabolismo , Endospermo/citología , Endospermo/metabolismo , Frutas/genética , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Hibridación in Situ , Óvulo Vegetal/citología , Óvulo Vegetal/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Semillas/citología , Semillas/metabolismo , Factores de Tiempo , Zea mays/embriología , Zea mays/genéticaRESUMEN
The decrease of strawberry (Fragariaxananassa Duch.) fruit firmness observed during ripening is partly attributed to pectolytic enzymes: polygalacturonases, pectate lyases and pectin methylesterases (PMEs). In this study, PME activity and pectin content and esterification degree were measured in cell walls from ripening fruits. Small green, large green, white, turning, red and over-ripe fruits from the Elsanta cultivar were analyzed. Using the 2F4 antibody directed against the calcium-induced egg box conformation of pectin, we show that calcium-bound acidic pectin was nearly absent from green and white fruits, but increased abruptly at the turning stage, while the total pectin content decreased only slightly as maturation proceeded. Isoelectrofocalisation performed on wall protein extracts revealed the expression of at least six different basic PME isoforms. Maximum PME activity was detected in green fruits and steadily decreased to reach a minimum in senescent fruits. The preliminary role of PMEs and subsequent pectin degradation by pectolytic enzymes is discussed.
Asunto(s)
Hidrolasas de Éster Carboxílico/metabolismo , Fragaria/enzimología , Fragaria/fisiología , Frutas/enzimología , Frutas/fisiología , Pectinas/metabolismo , Ácidos/metabolismo , Hidrolasas de Éster Carboxílico/aislamiento & purificación , Esterificación , Fragaria/embriología , Frutas/embriología , Focalización Isoeléctrica , Isoenzimas/aislamiento & purificación , Isoenzimas/metabolismoRESUMEN
Sorbitol, the primary photosynthate and translocated carbohydrate in apple (Malusxdomestica Borkh.), is converted to fructose by sorbitol dehydrogenase (SDH; EC 1.1.1.14) which is active in apple fruit throughout development. In the apple genome, nine SDH genes have been isolated and their sequences characterized, but their individual expression patterns during apple fruit set and development have not been determined. The objective of this work was to ascertain if SDH genes are differentially expressed and how their patterns of expression may relate to SDH activity in apple seed and cortex during early fruit development. Seed SDH activity was found to be much higher than cortex SDH activity per mg and g fresh weight (FW), and seed SDH activity contributed significantly to whole fruit SDH activity during weeks 2-5 after bloom. Five of the nine SDH genes present in the apple genome were expressed in apple fruit. Two SDH genes, SDH1 and SDH3, were expressed in both seed and cortex tissues. SDH2 expression was limited to cortex, while SDH6 and SDH9 were expressed in seed tissues only. SDH isomeric proteins of different pI values were detected in apple fruit. SDH isomers with pI values of 4.2, 4.8, 5.5, and 6.3 were found in seeds, and SDH isomers with pI values of 5.5, 6.3, 7.3, and 8.3 were found in cortex. The present work is the first to show that SDH is highly active in apple seed and that SDH genes are differentially expressed in seed and cortex during early development.
Asunto(s)
Frutas/enzimología , L-Iditol 2-Deshidrogenasa/metabolismo , Malus/enzimología , Proteínas de Plantas/metabolismo , Northern Blotting , Western Blotting , Electroforesis en Gel Bidimensional , Frutas/embriología , Frutas/crecimiento & desarrollo , L-Iditol 2-Deshidrogenasa/genética , Malus/embriología , Malus/crecimiento & desarrollo , Proteínas de Plantas/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Semillas/metabolismoRESUMEN
Regeneration of the Brazilian Caatinga forest may be restricted by the naturally low diversity and density of fruit-eating animals, which has been aggravated by local faunal extinction induced by human activities. We made a preliminary evaluation of the potential seed-dispersal role of capuchin (Cebus apella libidinosus) and howler monkeys (Alouatta caraya) in Serra da Capivara National Park. The monkeys dispersed at least 26 species. Alouatta dispersed larger seeds than Cebus, and the two species apparently dispersed seeds in different local habitats. Seed dispersal by monkeys potentially makes a significant contribution to Caatinga regeneration.
Asunto(s)
Alouatta/fisiología , Cebus/fisiología , Conducta Alimentaria , Semillas/crecimiento & desarrollo , Árboles/crecimiento & desarrollo , Animales , Brasil , Conservación de los Recursos Naturales , Heces , Frutas/embriología , Semillas/anatomía & histologíaRESUMEN
Using proteomic analysis including 2-DE, image analysis, and protein identification with LC-MS/MS, an investigation aimed at a better understanding of the differentially expressed proteins and/or gene products was carried out with total cell extracts from placental tissues in nonpungent (Capsicum annuum cv. Saeng-Ryeog #213) and pungent peppers (C. annuum cv. Saeng-Ryeog #211). Mobilization of the most abundant proteins, which were on the gels of pH ranges of 4-7, 4.5-5.5, 5.5-6.7, and 6-9, and showed very similar profiles in the two tissues, revealing approximately 2600 protein spots consisting of 1200 on pH 4-7, 600 on 4.5-5.5, 550 on 5.5-6.7, 250 on 6-9. Of these, 37 protein spots, which appeared in only pungent tissues but not in nonpungent tissues or markedly increased in their staining intensities on the gels from pungent tissue, were selected, excised, in-gel trypsin digested, and analyzed by LC-ESI-MS/MS. Peptide MS/MS data were searched against publicly available protein and EST databases, and 22 proteins were identified. Based on this result, we tested and compared the differential expression during fruit development on the 2-DE gels with total cell extracts from placental tissues of pungent and nonpungent peppers at an interval of 10 days from 10 to 40 days after flowering. In addition, this differential protein expression was further confirmed for some subsets of candidates by Northern-blot analysis with RNA samples from placental tissues harvested from each pepper fruit at the same sampling intervals. In this study, the physiological implications, revealed from the experimental data in the levels of proteome and transcripts, are discussed in the context of a complex biosynthesis network of capsaicinoids in pepper cells responsive to pungency.
Asunto(s)
Capsaicina/metabolismo , Capsicum/metabolismo , Frutas/metabolismo , Proteínas de Plantas/biosíntesis , Proteoma/biosíntesis , Secuencia de Aminoácidos , Capsicum/embriología , Capsicum/crecimiento & desarrollo , Electroforesis en Gel Bidimensional , Frutas/embriología , Frutas/crecimiento & desarrollo , Datos de Secuencia Molecular , Proteínas de Plantas/análisis , Proteínas de Plantas/química , Proteoma/análisis , Proteoma/química , VolatilizaciónRESUMEN
A facile method for enzymatic glycosylation of 4-substituted benzyl alcohols and tyrosol with glucose in a monophasic aqueous-dioxane medium was reported, using a crude meal of apple seed as a new catalyst. The corresponding beta-d-glucosides were synthesized in moderate yields (13.1-23.1%), among which the salidroside was obtained in 15.8% yield.