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.

2013-10-01 | E-GEOD-33003 | biostudies-arrayexpress

Citrus sinensis cultivar:X 639

Project description:Seasonal citrus X 639 rootstock transcriptome in response to HLB

| PRJNA739187 | ENA

Expression data of sweet orange in response to Candidatus Liberibacter asiaticus infection at advanced stage

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.

2011-07-06 | E-GEOD-29633 | biostudies-arrayexpress

Transcription profiling of petioles and laminar abscission zone enriched tissues from Citrus clementina following ethylene treatment

Project description:Transcription profiling of the ethylene-induced abscission process in laminar abscission zone enriched tissues and petiole of debladed mature citrus leaf explants. Samples taken at 0, 6, 12, 24 and 36h after ethylene treatment (10 ul/l) were compared.

2008-12-31 | E-MEXP-1428 | biostudies-arrayexpress

Comparative analysis of stylar canal cells transcriptome in clementine mandarin (Citrus clementina)

Project description:Compared to what is known in model species, reproductive biology in citrus is still poorly understood. Although in recent years several efforts have been made to study pollen-pistil interaction and self-incompatibility, little information is available about the molecular mechanisms regulating these processes. We performed microarray analysis for the identification of candidate genes involved in pollen-pistil interaction and self-incompatibility in clementine (Citrus clementina Hort. ex Tan.). The analysis was performed comparing the transcriptome of laser-microdissected stylar canal cells isolated from two clementine genotypes differing for self-incompatibility response (‘Comune’, self-incompatible; and ‘Monreal’, a self compatible mutation of ‘Comune’).

2012-02-15 | GSE33014 | GEO

Transcriptional response of susceptible and tolerant citrus to infection with Candidatus Liberibacter asiaticus

Project description:Candidatus Liberibacter asiaticus (Las), a non-culturable phloem-limited bacterium, is the suspected causal agent of Huanglongbing (HLB) in Florida. HLB is one of the most devastating diseases of citrus and no resistant cultivars have been identified to date, though tolerance has been suggested in the genus Poncirus. A recent study conducted in our laboratory demonstrated tolerance of US-897, a hybrid of Poncirus trifoliata (L. Raf.) and the susceptible ‘Cleopatra’ mandarin (Citrus reticulata Blanco), to Ca. L. asiaticus, the presumed causal agent of HLB in Florida (Albrecht & Bowman, HortScience 46 (2011) 16-22). This study compares transcriptional changes in tolerant US-897 and susceptible ‘Cleopatra’ mandarin seedlings in response to infection with Las using the Affymetrix GeneChip citrus array with the main objective of identifying genes associated with tolerance to HLB. Such genes may be suitable as potential targets for biotechnology approaches, providing one strategy to possibly control this destructive disease of citrus.

2011-10-04 | GSE30502 | GEO

Transcriptome profiling of Candidatus Liberibacter asiaticus in citrus and psyllids

Project description:Candidatus Liberibacter asiaticus (Las) is an emergent bacterial pathogen associated with the devastating citrus Huanglongbing (HLB), also known as the greening disease. Vectored by the Asian Citrus Psyllid (Diaphorina citri), Las colonizes the phloem tissue of citrus. So far, efforts of cultivating Las in vitro have not been successful and dual-transcriptome analyses could only detect ~100 Las genes due to the low abundance of bacterial RNA in infected citrus/psyllid tissues. Therefore, the biology of this pathogen is poorly understood. Here, we established a procedure to enrich Las RNA for transcriptome analysis in order to obtain insights into the interactions of Las with its two hosts. We were able to confidently determine the expression profiles of >400 Las genes, including 106 that were differentially expressed between citrus and psyllids. Genes related to transcription/translation and defense were found to be upregulated in citrus; whereas genes upregulated in psyllids are involved in metabolic pathways related to tricarboxylic acid (TCA) cycle. Genes encoding the succinate dehydrogenase and NADH quinone oxidoreductase complexes, as well as the flagellar system are also expressed to higher levels in psyllids. We also analyzed the relative expression levels of Sec-delivered effectors, which are considered key virulence factors of Las. This work advances our understanding of the HLB biology and offers novel insight into the HLB pathogenesis.

2021-09-01 | GSE180624 | GEO

Citrus clementina

Project description:Citrus clementina Transcriptome or Gene expression

| PRJNA212010 | ENA