Proteomics analysis reveals novel host molecular mechanisms associated with thermotherapy of ‘Ca. Liberibacter asiaticus’-infected citrus plants

BMC Plant Biology

Research Article

Chika C. Nwugo¹  Hong Lin¹  Yong-ping Duan²  Melissa S. Doud² 

[1] USDA, Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, 9611 South Riverbend Avenue, 93648, Parlier, CA, USA;USDA, Agricultural Research Service, U.S. Horticultural Research Laboratory, 34945, Fort Pierce, FL, USA;

关键词: Citrus;    Proteomics;    Huanglongbing;    Host response;    Protein extraction;    Chaperones;    Defense-related proteins;    Heat treatment;    Photosynthesis-related proteins;   

DOI  :  10.1186/s12870-016-0942-x

 received in 2016-06-20, accepted in 2016-11-02,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundCitrus Huanglongbing (HLB), which is linked to the bacterial pathogen ‘Ca. Liberibacter asiaticus’ (Las), is the most devastating disease of citrus plants, and longer-term control measures via breeding or genetic engineering have been unwieldy because all cultivated citrus species are susceptible to the disease. However, the degree of susceptibility varies among citrus species, which has prompted efforts to identify potential Las resistance/tolerance-related genes in citrus plants for application in breeding or genetic engineering programs. Plant exposure to one form of stress has been shown to serendipitously induce innate resistance to other forms of stress and a recent study showed that continuous heat treatment (40 to 42 °C) reduced Las titer and HLB-associated symptoms in citrus seedlings. The goal of the present study was to apply comparative proteomics analysis via 2-DE and mass spectrometry to elucidate the molecular processes associated with heat-induced mitigation of HLB in citrus plants. Healthy or Las-infected citrus grapefruit plants were exposed to room temperature or to continuous heat treatment of 40 °C for 6 days.ResultsAn exhaustive total protein extraction process facilitated the identification of 107 differentially-expressed proteins in response to Las and/or heat treatment, which included a strong up-regulation of chaperones including small (23.6, 18.5 and 17.9 kDa) heat shock proteins, a HSP70-like protein and a ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO)-binding 60 kDa chaperonin, particularly in response to heat treatment. Other proteins that were generally down-regulated due to Las infection but up-regulated in response to heat treatment include RuBisCO activase, chlorophyll a/b binding protein, glucosidase II beta subunit-like protein, a putative lipoxygenase protein, a ferritin-like protein, and a glutathione S-transferase.ConclusionsThe differentially-expressed proteins identified in this study highlights a premier characterization of the molecular mechanisms potentially involved in the reversal of Las-induced pathogenicity processes in citrus plants and are hence proposed targets for application towards the development of cisgenic Las-resistant/tolerant citrus plants.

【 授权许可】

CC BY   
© The Author(s). 2016