Project description:The main objective of the present study was to identify citrus transcrition factors putatively involved in the juvenile to adult transition in citrus. A oligonucleotide microarray containing 1152 putative unigenes of citrus transcription factors was used. Pineapple sweet orange (C. sinensis (L.) was analyzed in two diferent developmental stages, junenile and adult. Four replicates for each sample category were generated and for each genotipe juvenile versus adult samples were compared . Comparative transcriptomic hybridization
Project description:We have used the citrus GeneChip array (GPL5731) to survey the transcription profiles of sweet orange in response to the bacterial pathogens Xanthomonas axonopodis pv. citri (Xac) and Xanthomonas axonopodis pv. aurantifolii (Xaa). Xac is the causal agent of the citrus canker disease on a wide range of citrus species, including sweet oranges (Citrus sinensis). On the other hand, Xaa is pathogenic to Mexican lime (Citrus aurantifolia) only, and in sweet orange it triggers a defense response. In order to identify the genes induced during the defense response (Xaa-responsive genes) or citrus canker development (Xac-responsive genes), we conducted microarrays hybridization experiments at 6 and 48 hours after bacterial infiltration (habi). The analysis revealed that genes commonly modulated by Xac and Xaa are associated with basal defenses normally triggered by pathogen-associated molecular patterns, including those involved in reactive oxygen species production and lignification. Significantly, Xac-infected leaves showed considerable changes in the transcriptional profiles of defense-, cell wall-, vesicle trafficking- and cell growth-related genes between 6 and 48 habi. This is consistent with the notion that Xac suppresses host defenses near the beginning of the infection and simultaneously changes the physiological status of the host to promote cell enlargement and division. Finally, Xaa triggered a MAP kinase signaling pathway involving WRKY and ethylene-responsive transcriptional factors known to activate downstream defense genes. Keywords: Comprehensive transcriptional analysis of the Citrus-Xanthomonas interaction Adult leaves of sweet orange were infiltrated with the bacterial suspensions or water (mock control). Two stages were selected after bacterial infiltration for RNA extraction and hybridization on Affymetrix microarrays. In total, these experiments consist of two biological replicates of six samples: water-infiltrated leaves, Xaa-infiltrated leaves and Xac-infiltrated leaves, at both 6 and 48 (habi).
Project description:The goal of the microarray experiment was to identify genes that were differentially expressed in NAD-treated and water-treated sweet orange leaf tissues. Results indicated that, compared with the water treatment, the NAD tretament triggered profound transcriptome changes in the citrus leaves, with about 1,200 genes being up-regulated or down-regulated by twofold or more.
Project description:Citrus greening or huanglongbing (HLB) is a devastating disease of citrus. HLB is associated with the phloem-limited fastidious prokaryotic alpha-proteobacterium Candidatus Liberibacter spp. In this report, we used sweet orange (Citrus sinensis) leaf tissue infected with 'Ca. Liberibacter asiaticus' and compared this with healthy controls. Investigation of the host response was examined with citrus microarray hybridization based on 30,171 sets expressed sequence tag sequences from several citrus species and hybrids. The microarray analysis indicated that HLB infection significantly affected expression of 624 genes whose encoded proteins were categorized according to function. The categories included genes associated with sugar metabolism, plant defense, phytohormone, and cell wall metabolism, as well as 14 other gene categories. Young, healthy Valencia sweet orange (C. sinensis) plants were graft inoculated with budwood from Ca. L. asiaticus-infected citrus plants. Prior to the innocualtion, the plants were confirmed to be Ca. L. asiaticus-free in ordinary and quantitative PCR tests. The presence of the bacteria in the inoculated plants was confirmed in both conventional and quantitative PCR with specific primers to Ca. L. asiaticus. The stem and root samples used for RNA extraction and hybridization on Affymetrix microarrays were obtained from three symptomatic and three healthy control trees of similar size, approximately 1 year after inoculation.
Project description:We have used the citrus GeneChip array (GPL5731) to survey the transcription profiles of sweet orange in response to the bacterial pathogens Xanthomonas axonopodis pv. citri (Xac) and Xanthomonas axonopodis pv. aurantifolii (Xaa). Xac is the causal agent of the citrus canker disease on a wide range of citrus species, including sweet oranges (Citrus sinensis). On the other hand, Xaa is pathogenic to Mexican lime (Citrus aurantifolia) only, and in sweet orange it triggers a defense response. In order to identify the genes induced during the defense response (Xaa-responsive genes) or citrus canker development (Xac-responsive genes), we conducted microarrays hybridization experiments at 6 and 48 hours after bacterial infiltration (habi). The analysis revealed that genes commonly modulated by Xac and Xaa are associated with basal defenses normally triggered by pathogen-associated molecular patterns, including those involved in reactive oxygen species production and lignification. Significantly, Xac-infected leaves showed considerable changes in the transcriptional profiles of defense-, cell wall-, vesicle trafficking- and cell growth-related genes between 6 and 48 habi. This is consistent with the notion that Xac suppresses host defenses near the beginning of the infection and simultaneously changes the physiological status of the host to promote cell enlargement and division. Finally, Xaa triggered a MAP kinase signaling pathway involving WRKY and ethylene-responsive transcriptional factors known to activate downstream defense genes. Keywords: Comprehensive transcriptional analysis of the Citrus-Xanthomonas interaction
Project description:Citrus greening or huanglongbing (HLB) is a devastating disease of citrus. HLB is associated with the phloem-limited fastidious prokaryotic alpha-proteobacterium Candidatus Liberibacter spp. In this report, we used sweet orange (Citrus sinensis) leaf tissue infected with 'Ca. Liberibacter asiaticus' and compared this with healthy controls. Investigation of the host response was examined with citrus microarray hybridization based on 30,171 sets expressed sequence tag sequences from several citrus species and hybrids. The microarray analysis indicated that HLB infection significantly affected expression of 624 genes whose encoded proteins were categorized according to function. The categories included genes associated with sugar metabolism, plant defense, phytohormone, and cell wall metabolism, as well as 14 other gene categories.
Project description:Citrus Huanglongbing (HLB, or greening) is one of the most severe diseases of citrus. Plant disease symptom development is considered to be the consequence of a number of molecular, cellular and physiological changes, and may also be associated with host defense responses. Understanding citrus host response to HLB may contribute to the development of new strategies to control this destructive disease. We performed microarray analysis to identify the differentially expressed genes in sweet orange in response to HLB infection using the Affymetrix GeneChipM-BM-. citrus genome array. Two-year-old seedlings of M-bM-^@M-^XMadam VinousM-bM-^@M-^Y sweet orange (Citrus sinensis L. Osbeck) were inoculated by grafting with bud sticks from HLB-diseased, PCR positive sweet orange plants. For mock-inoculated controls, the same types of plants were grafted with bud sticks from HLB-free, PCR negative sweet orange. At 7 months after inoculation, mature leaves were sampled from 3 individual HLB-diseased plants, and healthy leaves from 3 mock-inoculated plants as control. Total RNA was extracted from leaf samples and hybridized on Affymetrix microarrays.
Project description:• To dissect how the genes are dynamically and differentially expressed during fruit development in sweet orange, a comprehensive transcriptomic study was performed in a pleiotropic mutant (MT) and its wild type (WT). • The detection of the fruit transcriptomic changes was conducted at five stages of fruit development by deep sequencing; the obtained millions of reliable tags were mapped on orange unigenes and subjected to cluster analysis and functional categorization. Sugar and organic acid contents were determined based on the prediction of differential biological processes. • The global clustering analysis revealed a total of 14 expression patterns for the genes involved in fruit development of sweet orange. More than 94% of the genes showed differential expression during fruit development. Comparative transcripts profiling between WT and MT revealed that between 410 and 634 genes were significantly differentially expressed at the five stages. Functional categorization indicated that TCA cycle, carotenoid biosynthesis, and pentose phosphate pathway (OPP) were among the most regulated pathways. • This study provided a dynamic-view of the transcriptome changes during fruit ripening in sweet orange; the results highlighted a set of molecular processes involved in the formation of the mutation trait in the orange fruits. Investigate the transcriptome changes during five fruit developmental stages of two sweet orange genotypes
Project description:• To dissect how the genes are dynamically and differentially expressed during fruit development in sweet orange, a comprehensive transcriptomic study was performed in a pleiotropic mutant (MT) and its wild type (WT). • The detection of the fruit transcriptomic changes was conducted at five stages of fruit development by deep sequencing; the obtained millions of reliable tags were mapped on orange unigenes and subjected to cluster analysis and functional categorization. Sugar and organic acid contents were determined based on the prediction of differential biological processes. • The global clustering analysis revealed a total of 14 expression patterns for the genes involved in fruit development of sweet orange. More than 94% of the genes showed differential expression during fruit development. Comparative transcripts profiling between WT and MT revealed that between 410 and 634 genes were significantly differentially expressed at the five stages. Functional categorization indicated that TCA cycle, carotenoid biosynthesis, and pentose phosphate pathway (OPP) were among the most regulated pathways. • This study provided a dynamic-view of the transcriptome changes during fruit ripening in sweet orange; the results highlighted a set of molecular processes involved in the formation of the mutation trait in the orange fruits.