Transcriptome profiling of citrus fruit response to huanglongbing disease.
Huanglongbing (HLB) or "citrus greening" is the most destructive citrus disease worldwide. In this work, we studied host responses of citrus to infection with Candidatus Liberibacter asiaticus (CaLas) using next-generation sequencing technologies. A deep mRNA profile was obtained from peel of healthy and HLB-affected fruit. It was followed by pathway and protein-protein network analysis and quantitative real time PCR analysis of highly regulated genes. We identified differentially regulated pathways and constructed networks that provide a deep insight into the metabolism of affected fruit. Data mining revealed that HLB enhanced transcription of genes involved in the light reactions of photosynthesis and in ATP synthesis. Activation of protein degradation and misfolding processes were observed at the transcriptomic level. Transcripts for heat shock proteins were down-regulated at all disease stages, resulting in further protein misfolding. HLB strongly affected pathways involved in source-sink communication, including sucrose and starch metabolism and hormone synthesis and signaling. Transcription of several genes involved in the synthesis and signal transduction of cytokinins and gibberellins was repressed while that of genes involved in ethylene pathways was induced. CaLas infection triggered a response via both the salicylic acid and jasmonic acid pathways and increased the transcript abundance of several members of the WRKY family of transcription factors. Findings focused on the fruit provide valuable insight to understanding the mechanisms of the HLB-induced fruit disorder and eventually developing methods based on small molecule applications to mitigate its devastating effects on fruit production.
Plant Sciences Department, University of California Davis, Davis, California, United States of America.
Federico
F
Martinelli
Sandra L
SL
Uratsu
Ute
U
Albrecht
Russell L
RL
Reagan
My L
ML
Phu
Monica
M
Britton
Vincent
V
Buffalo
Joseph
J
Fass
Elizabeth
E
Leicht
Weixiang
W
Zhao
Dawei
D
Lin
Raissa
R
D'Souza
Cristina E
CE
Davis
Kim D
KD
Bowman
Abhaya M
AM
Dandekar
D000704:Analysis of Variance; D050260:Carbohydrate Metabolism / Q000235:genetics; D002957:Citrus / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D019295:Computational Biology; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D059014:High-Throughput Nucleotide Sequencing; D008954:Models, Biological; D010788:Photosynthesis / Q000235:genetics; D010935:Plant Diseases / Q000235:genetics* / Q000276:immunology / Q000382:microbiology*; D010937:Plant Growth Regulators / Q000378:metabolism; D017510:Protein Folding; D055550:Protein Stability; D012230:Rhizobiaceae; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics; D059467:Transcriptome
D010937:Plant Growth Regulators; D014157:Transcription Factors