利用叶绿素荧光成像技术监测 Heterobasidion parviporum 小分泌蛋白诱导的细胞死亡和植物体内防御基因表达的影响。

Chlorophyll fluorescence imaging for monitoring effects of Heterobasidion parviporum small secreted protein induced cell death and in planta defense gene expression.

机构信息

Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland; Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.

Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland.

出版信息

Fungal Genet Biol. 2019 May;126:37-49. doi: 10.1016/j.fgb.2019.02.003. Epub 2019 Feb 11.

DOI:10.1016/j.fgb.2019.02.003

PMID:30763724

Abstract

Heterobasidion parviporum Niemelä & Korhonen is a necrotrophic fungal pathogen of Norway spruce (Picea abies). The H. parviporum genome encodes numerous necrotrophic small secreted proteins (SSP) which might be important for promoting and sustaining the disease development. However, their transcriptional dynamics and plant defense response during infection are largely unknown. In this study, we identified a necrotrophic SSP named HpSSP35.8 and its coding gene was highly expressed in the pre-symptomatic phase of the host (Norway spruce) infection. We explored the impact of HpSSP35.8 on non-host Nicotiana benthamiana using Agrobacterium-mediated transient expression system under visible spectrum RGB imaging and chlorophyll fluorescence imaging. The results showed that HpSSP35.8 triggered a form of SSP-associated programmed cell death, accompanied by a decrease in the plant photosynthetic activity. Defense-related genes including WRKY12, ethylene response factor (ERF1α) and a chitinase gene PR4 were up-regulated in both HpSSP35.8-N. benthamiana interaction and H. parviporum-Norway spruce pathosystem. This study also highlighted the potential to use the chlorophyll fluorescence imaging approach to monitor both the indirect effects of SSP and also for the selection of other potential effector-like protein candidates.

摘要

短密木层孔菌（Heterobasidion parviporum）是云杉的一种专性坏死型真菌病原体。该菌基因组编码大量的坏死型小分泌蛋白（SSP），这些蛋白可能在促进和维持疾病发展方面发挥重要作用。然而，它们在感染过程中的转录动态和植物防御反应在很大程度上尚不清楚。在本研究中，我们鉴定了一种坏死型 SSP，命名为 HpSSP35.8，其编码基因在宿主（挪威云杉）感染的症状前阶段高度表达。我们使用 Agrobacterium 介导的瞬时表达系统，在可见光谱 RGB 成像和叶绿素荧光成像下，研究了 HpSSP35.8 对非宿主烟草（Nicotiana benthamiana）的影响。结果表明，HpSSP35.8 触发了一种与 SSP 相关的程序性细胞死亡形式，伴随着植物光合作用活性的降低。在 HpSSP35.8-N. benthamiana 互作和 H. parviporum-挪威云杉病理系统中，WRKY12、乙烯反应因子（ERF1α）和几丁质酶基因 PR4 等防御相关基因均上调。本研究还强调了使用叶绿素荧光成像方法来监测 SSP 的间接影响以及选择其他潜在效应子样蛋白候选物的潜力。