title: Digital Gene Expression Analysis of Ponkan Mandarin (Citrus reticulata Blanco) in Response to Asia Citrus Psyllid-Vectored Huanglongbing Infection.
abstract: Citrus Huanglongbing (HLB), the most destructive citrus disease, can be transmitted by psyllids and diseased budwoods. Although the final symptoms of the two main HLB transmission ways were similar and hard to distinguish, the host responses might be different. In this study, the global gene changes in leaves of ponkan (Citrus reticulata) mandarin trees following psyllid-transmission of HLB were analyzed at the early symptomatic stage (13 weeks post inoculation, wpi) and late symptomatic stage (26 wpi) using digital gene expression (DGE) profiling. At 13 wpi, 2452 genes were downregulated while only 604 genes were upregulated in HLB infected ponkan leaves but no pathway enrichment was identified. Gene function analysis showed impairment in defense at the early stage of infection. At late stage of 26 wpi, however, differentially expressed genes (DEGs) involved in carbohydrate metabolism, plant defense, hormone signaling, secondary metabolism, transcription regulation were overwhelmingly upregulated, indicating that the defense reactions were eventually activated. The results indicated that HLB bacterial infection significantly influenced ponkan gene expression, and a delayed response of the host to the fast growing bacteria might be responsible for its failure in fighting against the bacteria.
authors.affiliation: Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China. zhongyun99cn@163.com.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China. ld0532cheng@126.com.|Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou 350002, China. ld0532cheng@126.com.
authors.forename: Chunzhen
authors.initials: C
authors.lastname: Cheng
authors.affiliation: Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China. jb-clinnic@webmail.hzau.edu.cn.|Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization Ministry of Agriculture, Guangzhou 510640, China. jb-clinnic@webmail.hzau.edu.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China. jiangnonghui2002@163.com.|Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization Ministry of Agriculture, Guangzhou 510640, China. jiangnonghui2002@163.com.
authors.forename: Nonghui
authors.initials: N
authors.lastname: Jiang
authors.affiliation: Institute of Horticultural Biotechnology, Fujian Agriculture and Forestry University, Fuzhou 350002, China. zhyy0425@126.com.
authors.forename: Yongyan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China. fanshu2005@163.com.|Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization Ministry of Agriculture, Guangzhou 510640, China. fanshu2005@163.com.
authors.forename: Minlun
authors.initials: M
authors.lastname: Hu
authors.affiliation: Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China. gy_zhong@163.com.|Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization Ministry of Agriculture, Guangzhou 510640, China. gy_zhong@163.com.
authors.forename: Guangyan
authors.initials: G
authors.lastname: Zhong
mesh_terms: D020561:Alphaproteobacteria; D000818:Animals; D002957:Citrus / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D006430:Hemiptera / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000378:metabolism* / Q000382:microbiology
keywords: Asian citrus psyllids (ACP); Citrus Huanglongbing (HLB); differentially expressed genes (DEGs); digital gene expression (DGE); ponkan mandarin