Data from: Proteomics analysis reveals novel host molecular mechanisms associated with thermotherapy of 'Ca. Liberibacter asiaticus'-infected citrus plants

Background
Citrus Huanglongbing (HLB), which is linked to the bacterial Candidatus 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.
Results
An 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.
Conclusions
The 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. Resources in this dataset:Resource Title: Appendix 1. Mascot match results and peptide sequences of the 130 differentially-expressed spots - Download Excel. File Name: 12870_2016_942_MOESM1_ESM.xlsx, url: https://static-content.springer.com/esm/art:10.1186/s12870-016-0942-x/MediaObjects/12870_2016_942_MOESM1_ESM.xlsx

背景
柚类黄龙病（HLB），与细菌性病原体‘Candidatus Liberibacter asiaticus’（Las）相关联，是柚类植物最为毁灭性的疾病。由于所有栽培的柚类物种均易感染此病，因此通过育种或基因工程采取的长期控制措施难以实施。然而，柚类物种对疾病的易感性存在差异，这促使研究者们努力识别柚类植物中与Las抗性/耐受性相关的潜在基因，以便应用于育种或基因工程计划中。研究表明，植物暴露于一种形式的应激可能会意外诱导对其他形式应激的先天抗性，最近的研究表明，连续的热处理（40至42°C）可以降低柚类幼苗中的Las滴度和HLB相关症状。本研究的目的是通过二维电泳和质谱进行比较蛋白质组学分析，阐明与柑橘植物中热诱导的HLB缓解相关的分子过程。健康或Las感染的柚类葡萄柚植物分别暴露于室温或40°C的连续热处理6天。
结果
通过彻底的蛋白质提取过程，识别出107种在Las和/或热处理下差异表达的蛋白质，包括强上调的伴侣蛋白，包括小（23.6、18.5和17.9 kDa）热休克蛋白、一种HSP70样蛋白和一种与核糖-1,5-二磷酸羧化酶氧合酶（RuBisCO）结合的60 kDa伴侣蛋白，特别是在热处理后的反应中。其他蛋白质因Las感染而普遍下调，但在热处理下上调，包括RuBisCO活化酶、叶绿素a/b结合蛋白、葡萄糖苷酶IIβ亚基样蛋白、一种假定的脂氧合酶蛋白、一种铁蛋白样蛋白和一种谷胱甘肽S转移酶。
结论
本研究中鉴定的差异表达蛋白突显了柑橘植物中Las诱导致病性过程逆转可能涉及的分子机制的初步表征，因此被提议作为开发抗Las或耐受Las的转因柚类植物的靶点。本数据集中包含的资源：资源标题：附录1. 130个差异表达点的Mascot匹配结果和肽序列 - 下载Excel。文件名：12870_2016_942_MOESM1_ESM.xlsx，网址：https://static-content.springer.com/esm/art:10.1186/s12870-016-0942-x/MediaObjects/12870_2016_942_MOESM1_ESM.xlsx