Project description:To date, little is known about molecular mechanisms by which woody plants engage symbiosis with arbuscular mycorrhizal (AM) fungi. Here we investigated transcriptome changes in the roots of Poncirus trifoliata (the most common citrus rootstock) that are induced during colonization of an AM fungus Glomus versiforme (Gv). A total of 282 Poncirus genes were differentially expressed in response to Gv colonization, of which 138 could identify homologous genes from the model legume Medicago truncatula that also exhibit similar AM-induced transcriptional changes, while the remaining 144 do not. A high proportion of the AM-responsive Poncirus genes are predicted to be involved in transcription regulation, transport process, cellular organization and protein degradation, implicating these processes in the establishment of AM symbiosis. Promoter-GUS analysis of six AM-induced Poncirus genes [encoding an exocyst subunit (PtrEXO70I), two transcription factors (PtNAC1 and PtPALM1), one chitinase (PtrChit2), one plastid movement associated protein (PtrPMI2) and one lipase (PtrLipase3)] showed that all of them exhibit specific expression in arbuscule-containing root cortical cells, suggesting their potential involvement in establishing AM symbiosis. Notably, down-regulation of the ortholog of PtrExo70I in Medicago by RNAi significantly impaired arbuscule development, indicating that Exo70I is an important host component required for arbuscule development in root cortical cells. This study not only helps identify conserved host genes engaged in AM symbiosis but should also guide future mechanistic studies of potentially Poncirus-specific events during its symbiosis with AM fungi.
Project description:Genome-wide screening and characterization of long non-coding RNAs involved in flowering development of citrus (Poncirus trifoliata L. Raf.) by RNA sequencing
Project description:Deep sequencing-based characterization of transcriptome and transcriptional profiling of trifoliate orange (Poncirus trifoliata (L.) Raf.) in response to cold stress
Project description:Salt stress, especially saline-alkali stress, has seriously negative effect on citrus production. Ziyang xiangcheng (Citrus junos Sieb.) (Cj) has been reported as a saline-alkali stress and iron deficiency tolerant citrus rootstock. However, the molecular mechanism of its saline-alkali stress tolerance is still not clear. Two citrus rootstocks and one navel orange scion, Cj, Poncirus trifoliate (Poncirus trifoliata (L.) Raf.) (Pt) and ‘Lane Late’ navel orange (Citrus sinensis (L.) Osb.) (LL), were used in this study. The grafted materials Cj+LL and Pt+LL grown in calcareous soil were used to identify genes and pathways responsive to saline-alkali stress using RNA-seq. The seedlings of Cj and Pt grown in the solutions with different gradient pH value were used to perform a supplement experiment. Comprehensively analyzing the data of RNA-seq, physiology and biochemistry, agronomic traits and mineral elements of Cj+LL, Pt+LL, Cj and Pt, several candidate pathways and genes were identified to be highly regulated under saline-alkali stress. Here, we propose citrate is important for the tolerance to iron deficiency and the jasmonate (JA) biosynthesis and signal transduction pathway may play a crucial role in tolerance to saline-alkali stress in citrus by interacting with other plant hormones, calcium signaling, ROS scavenging system and lignin biosynthesis.
Project description:A microarray containing 62,876 unigenes selected from CitEST database and prepared by Nimblegen Systems was used for identifying candidate resistance genes against P. parasitica at 48 hours after inoculation Four resistant and four susceptible F1 hybrids were selected from the population derived from the cross between Citrus sunki Hort. ex. Tan. and Poncirus trifoliate (L.) Raf cv. Rubidoux, respectively susceptible and resistant to P. parasitica. It was proposed that differentially expressed genes between resistant and susceptible hybrids and their parents provide essential candidates for identifying transcripts involved in disease resistance A total of 62,876 unigenes (18,712 unigenes of Citrus sinensis; 31,583 unigenes of Citrus reticulata and 12,581 unigenes of Poncirus trifoliate) selected from CitEST database assembled from the EST submitted to NCBI (Genebank accession number EY649559 to EY842485) were used to construct genome-wide oligonucleotide cDNA microarrays by Roche NimbleGen Systems using a multi-step approach to select probes with optimal predicted hybridization characteristics. Three probes were selected per unigene, comprising a probe set, and each probe set is represented on the final array by two replicates. All probes were designed as ‘‘perfect match’’ (PM) oligonucleotides (oligos).
Project description:Identification and comparative profiling of microRNAs in an early flowering mutant of trifoliate orange (Poncirus trifoliata (L.) Raf.) and its wild type by genome-wide high throughput sequencing