Transcription profiling of barley anthers: effect of mannitol treatment on microspore embryogenesis
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ABSTRACT: we analyzed the anther transcriptome before and after 4 days of mannitol treatment using the 22k Barley1 GeneChip Experiment Overall Design: one genotype (DH line 46), two treatments (4 days of mannitol treatment and control) and three repeats each treatment
Project description:Arabidopsis is a host to the fungal powdery mildew pathogen, Erysiphe cichoracearum, and a nonhost to Blumeria graminis f.sp. hordei, the powdery mildew pathogenic on barley. A screen for mutants that allowed increased entry by this inappropriate or nonhost pathogen on Arabidopsis led to the identification of PEN3. While pen3 mutants permitted both increased penetration and increased hyphal growth by B. g. hordei, they were unexpectedly resistant to E. cichoracearum. This resistance was correlated with the appearance of chlorotic patches and was salicylic acid-dependent. Consistent with this observation, microarray analysis revealed that the salicylic acid defense pathway was hyper-induced in pen3 relative to wild type following inoculation with either E. cichoracearum or B. g. hordei. The pen3 phenotypes result from a loss of function of AtPDR8, a ubiquitously and highly expressed ATP binding cassette transporter. PEN3 protein tagged with green fluorescent protein localized to the plasma membrane in uninfected cells. In infected leaves, the protein concentrated to high levels at infection sites and surrounded fungal penetration pegs. We hypothesize that PEN3 may be involved in exporting toxic substrates to sites of infection and that accumulation of these substrates intracellularly in the pen3 mutant may secondarily activate the salicylic acid pathway. Experiment Overall Design: Three week-old wild-type Col and mutant pen3 Arabidopsis thaliana plants were inoculated with Erysiphe cichoracearum, Blumeria graminis hordei, or not inoculated. 1 day post inoculation 16 rosettes were harvested per replicate. 4 replicates were perfomerd per treatment.
Project description:In this study we used the Affymetrix Barley 1 GeneChip to investigate transcriptome responses of barley cv. Morex to ABA treatment, at two time points, each including triplicated measurements Experiment Overall Design: Plants were grown at 20ºC for seven days.
Project description:In this study we used the Affymetrix Barley 1 GeneChip to investigate transcriptome responses of barley cv. Dicktoo to low temperature, including triplicated measurements of cold, freeze/thaw cycles and de-acclimation over 33 days. Experiment Overall Design: Plants were grown at 20ºC for seven days and subject to a symmetrical cycle of acclimation, cold, freeze-thaw, and deacclimation. Chilling began by decreasing the temperature overnight from 20ºC to 4ºC at a rate of 1.3ºC�h-1 and maintaining temperatures of 4 ºC in the day and 2ºC at night for 5 days. Freeze-thaw cycling lasted 12 days with day temperatures of 4ºC and night temperatures gradually decreasing from -2ºC the first night to -4ºC for three nights and -10ºC for four nights, then recovering to -4ºC for three nights and -2ºC for one night. This treatment was designed to allow daily freeze-thaw cycling and protein synthesis. Chilling conditions (4ºC day, 2ºC night) were resumed for five days, followed by deacclimation with increasing temperature to 20ºC overnight and maintaining for three days. Sampling was done at four different times, each at the 11th hour of light to avoid circadian effects: 1) before chilling treatment, 2) five days after initiation of chilling treatment, 3) eight days into freeze-thaw treatment and 4) three days into de-acclimation.
Project description:In mandarin (Citrus reticulata Blanco), rind separation is an essential trait for marketing, as it confers easy-peeling, an inheritable trait whose genetic basis has not yet been characterized. To this end, we used the 30 K Affymetrix Citrus GeneChip to compare gene expression in albedo tissues of an easy-peeling genotype (Clementine Nules) to a less easy-peeling hybrid genotype (Lee x Nova, USDA 88-2) at three time points: before, at and after the onset of rind separation. A high percent of genes were detected reliably by the chip (76.1 %), and Principal Component Analysis (PCA) based on these genes showed that three replicates were well clustered, indicating the reliability of the data set. Functional analysis of genes showing >5-fold difference in expression between Clementine Nules and Lee x Nova across three developmental points suggested that the transcriptome of the two varieties diverges as the maturation process advances. A pectin methylesterase was expressed at levels more than 100-fold higher in Clementine Nules than in Lee x Nova at all three time points and two genes encoding for pectinases were more than 10-fold higher in Clementine Nules than in Lee x Nova during the last sampling time. Different hydrolases, a glucanase and a carbohydrate kinase were higher in Nules than in Lee x Nova. Higher expression of two cellulose synthases, an expansin and an aquaporin was observed in the easy peel genotype Clementine Nules. The difference between Clementine Nules and Lee x Nova at the transcript level suggests that three main molecular mechanisms are involved in the easy peeling trait: 1) lower cell adhesion, 2) pronounced degradation of albedo cell wall polysaccharides, and 3) high and extended cell expansion rate of the rind. We used the 30 K Affymetrix Citrus GeneChip to compare gene expression in albedo tissues of an easy-peeling genotype (Clementine Nules) to a less easy-peeling hybrid genotype (Lee x Nova, USDA 88-2) at three time points (16 arrays): before, at and after the onset of rind separation.
Project description:In this study we used the Affymetrix Barley 1 GeneChip to investigate transcriptome responses of barley cv. Morex to drought over 21 days based on five triplicated stress treatments and a wide range of soil water content treatments. Experiment Overall Design: Three control were collected at 91% SWC. Five soil water content conditions (SWC) were examined (approximately 68% SWC, 38% SWC, 20% SWC, 11% SWC and 9% SWC) and three samples were analysed for each of these.
Project description:In this study we used the Affymetrix Barley 1 GeneChip to investigate transcriptome responses of barley cv. Morex to low temperature, including triplicated measurements of cold, freeze/thaw cycles and de-acclimation over 33 days. Experiment Overall Design: Plants were grown at 20ºC for seven days and subject to a symmetrical cycle of acclimation, cold, freeze-thaw, and deacclimation. Chilling began by decreasing the temperature overnight from 20ºC to 4ºC at a rate of 1.3ºCâ¢h-1 and maintaining temperatures of 4 ºC in the day and 2ºC at night for 5 days. Freeze-thaw cycling lasted 12 days with day temperatures of 4ºC and night temperatures gradually decreasing from -2ºC the first night to -4ºC for three nights and -10ºC for four nights, then recovering to -4ºC for three nights and -2ºC for one night. This treatment was designed to allow daily freeze-thaw cycling and protein synthesis. Chilling conditions (4ºC day, 2ºC night) were resumed for five days, followed by deacclimation with increasing temperature to 20ºC overnight and maintaining for three days. Sampling was done at four different times, each at the 11th hour of light to avoid circadian effects: 1) before chilling treatment, 2) five days after initiation of chilling treatment, 3) eight days into freeze-thaw treatment and 4) three days into de-acclimation.
Project description:Using the ATH1 Affymetrix microarrays consisting of about 23,000 genes, we examined the response of Arabidopsis seedlings to chito-tetramers, chito-octamers and hydrolyzed chitin after 30 min of treatment.
Project description:Burkholderia multivorans was grown on agar plates containing mannitol as substrate and compared to growth on control plates containing mannose
Project description:Saccharomyces cerevisiae normally cannot assimilate mannitol, a promising brown macroalgal carbon source for bioethanol production. To date, the molecular mechanisms underlying this inability remain unknown. Here, we found that cells acquiring mannitol-assimilating ability appeared from wild-type S. cerevisiae strain during prolonged culture in mannitol medium. Our microarray analysis revealed that genes for putative mannitol dehydrogenase and hexose transporters were up-regulated in cells acquiring mannitol-assimilating ability. Take account of our other results including complementation analysis and cell growth data, we demonstrated that this acquisition of mannitol-assimilating ability was due to the spontaneous mutation in the gene encoding Tup1 or Cyc8. Tup1-Cyc8 is the general corepressor complex involved in the repression of many kinds of genes. Thus, it is suggested that the inability of wild-type S. cerevisiae to assimilate mannitol can be attributed to the transcriptional repression of a set of genes involved in mannitol utilization by Tup1-Cyc8 corepressor. In other words, Tup1-Cyc8 is a key regulator of mannitol metabolism in S. cerevisiae. We also showed that S. cerevisiae strain which carries mutant allele of TUP1 or CYC8 produced ethanol from mannitol efficiently. Especially, strain carrying mutant allele of CYC8 showed high tolerance to salt, which is superior to other ethanologenic microorganisms. This characteristic is highly beneficial to produce bioethanol from marine biomass. Taken together, Tup1-Cyc8 can be an ideal target to develop a yeast-algal bioethanol production system. To figure out how Mtl+ strains (cells acquiring ability to grow in mannitol medium) had acquired the ability to assimilate mannitol, we performed genome-wide analysis by using Nimblegen microarrays.