Additional file 10: Figure S7. of Transcriptional analysis of sweet orange trees co-infected with ‘Candidatus Liberibacter asiaticus’ and mild or severe strains of Citrus tristeza virus

Expression of the actin gene estimated by RT-qPCR. HC, healthy control; B2/232, CTV-B2/CaLas-B232; B6/232, CTV-B6/CaLas-B232. Y-axis, Cq value. Bars with standard error of the mean expression level of the actin gene with three technical replicates for each biological replicate. (PDF 56 kb

Le Courrier

30 janvier 18391839/01/30 (N30)

Differentially expressed genes involved in starch metabolism (A) and photosynthesis (B).

<p>Colored squares indicate up- or down-regulated genes with log₂ fold change (FC) ≥ 1.00 or ≤ -1.00.</p

Comparative PageMan display of perturbed pathways in <i>C</i>Las-affected <i>C</i>. <i>hystrix</i> and <i>C</i>. <i>sinensis</i>.

<p>The log₂ fold change of gene expression (mock-inoculated controls versus CLas-inoculated plants) was input into PageMan and subjected to a Wilcoxon test. Results were shown as a false-color heat-map-like display. Significantly up-regulated pathways are colored in red, while those colored in green are significantly down-regulated. Pathways without significant changes are white. Names of pathways are indicated on the right panel. CH, CH-M-VS-CH-HLB; CS, CS-M-VS-CS-HLB.</p

Nucleotide diversity of <i>citrus bark cracking viroid</i> (CBCVd) sequences from Pakistan, China, and other countries^a.

<p>Nucleotide diversity of <i>citrus bark cracking viroid</i> (CBCVd) sequences from Pakistan, China, and other countries^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198022#t003fn001" target="_blank">a</a>}.</p

Gene ontology classification of differentially expressed genes in different citrus hosts in response to ‘<i>Candidatus</i> Liberibacter asiaticus’.

<p>BP, Biological Process; CC, Cell Component; MF, Molecular Function.</p

Statistic of differentially expressd genes (DEGs) of different citrus cultivars in response to <i>C</i>Las.

<p>CH, <i>Citrus hystrix</i>; CS, <i>C</i>. <i>sinensis</i>; M, Mock/healthy; HLB, Huanglongbing; CH-M-VS-CH-HLB, DEGs in HLB-infected <i>C</i>. <i>hystrix</i> compared with healthy control; CS-M-VS-CS-HLB, DEGs in HLB-infected <i>C</i>. <i>sinensis</i> compared with healthy control; CS-M-VS-CH-M, DEGs between healthy <i>C</i>. <i>hystrix</i> and healthy <i>C</i>. <i>sinensis</i>; CS-HLB-VS-CH-HLB, DEGs between HLB-infected <i>C</i>. <i>hystrix</i> and HLB-infected <i>C</i>. <i>sinensis</i>.</p

Primary and secondary structures of <i>citrus bark cracking viroid</i> (CBCVd) sequences from sub-clades A, B, C, D, E, and F and CBCVd reference sequence (NC003539).

<p>The mutations of CBCVd sequences from these sub-clades were shown in box.</p

Transcriptome sequencing reveals novel <i>Citrus bark cracking viroid</i> (CBCVd) variants from citrus and their molecular characterization - Fig 1

<p><b>Transcriptome reads mapped onto sequences of CBCVd-P3-1 (A) and P5-1 (B) in PCV-I and PCV-II libraries.</b> Dots represent mismatches of reads.</p

Comparative transcriptome analysis unveils the tolerance mechanisms of <i>Citrus hystrix</i> in response to ‘<i>Candidatus</i> Liberibacter asiaticus’ infection

<div><p>Citrus Huanglongbing (HLB), a highly devastating citrus disease, is associated with ‘<i>Candidatus</i> Liberibacter asiacitus’ (<i>C</i>Las), a member of phloem-inhabiting <i>α-proteobacteria</i>. HLB can affect all cultivated citrus and no cure is currently available. Previous studies showed that Kaffir lime (<i>Citrus hystrix</i>), primarily grown in South Asia and Southeast Asia, was tolerant to HLB but the molecular mechanism remains unknown. In this study, gene expression profiling experiments were performed on HLB-tolerant <i>C</i>. <i>hystrix</i> and HLB-susceptible <i>C</i>. <i>sinensis</i> three months after inoculation with <i>C</i>Las using RNA-seq data. Differentially expressed genes (DEGs) in the two citrus cultivars were mainly involved in diverse cellular functions including carbohydrate metabolism, photosynthesis, cell wall metabolism, secondary metabolism, hormone metabolism and oxidation/reduction processes. Notably, starch synthesis and photosynthesis process were not disturbed in <i>C</i>Las-infected <i>C</i>. <i>hystrix</i>. Most of the DEGs involved in cell wall metabolism and secondary metabolism were up-regulated in <i>C</i>. <i>hystrix</i>. In addition, the activation of peroxidases, Cu/Zn-SOD and POD4, may also enhance the tolerance of <i>C</i>. <i>hystrix</i> to <i>C</i>Las. This study provides an insight into the host response of HLB-tolerant citrus cultivar to <i>C</i>Las. <i>C</i>. <i>hystrix</i> is potentially useful for HLB-tolerant/resistant citrus breeding in the future.</p></div