Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, China.
State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, 650091, China.
Sci Rep. 2017 Nov 22;7(1):16083. doi: 10.1038/s41598-017-16401-6.
Tobacco brown spot, caused by Alternaria species, is a devastating tobacco disease. To explore the role of a group III histidine kinase (AlHK1) on A. longipes pathogenesis, the invasion progress of A. longipes was monitored. We found that the wild-type strain C-00 invaded faster than the AlHK1-disrupted strain HK∆4 in the early and middle infection stages and the reverse trend occurred in the late infection stage. Then, eight invasion transcriptomes were performed using RNA-Seq and 205 shared, 505 C-00 and 222 HK∆4 specific differentially expressed genes (DEGs) were identified. The annotation results showed seven antioxidant activity genes were specifically identified in the HKΔ4 DEGs. A subsequent experiment confirmed that HKΔ4 was more resistant to low concentrations oxidative stress than C-00. In addition, the results from 1) statistics for the number of DEGs, GO enriched terms, DEGs in clusters with rising trends, and 2) analyses of the expression patterns of some DEGs relevant for osmoadaptation and virulence showed that changes in C-00 infection existed mainly in the early and middle stages, while HKΔ4 infection arose mainly in the late stage. Our results reveal firstly the pathogenesis of A. longipes regulated by AlHK1 and provide useful insights into the fungal-plant interactions.
烟草褐色斑点病由交链孢菌引起，是一种毁灭性的烟草病害。为了探索组 III 组氨酸激酶（AlHK1）在长交链孢菌致病机制中的作用，我们监测了长交链孢菌的入侵进展。结果发现，野生型菌株 C-00 在早期和中期感染阶段的入侵速度比 AlHK1 缺失突变体 HK∆4 快，而在后期感染阶段则出现相反的趋势。然后，使用 RNA-Seq 进行了 8 个入侵转录组分析，鉴定出 205 个共享、505 个 C-00 和 222 个 HK∆4 特异性差异表达基因（DEGs）。注释结果表明，在 HKΔ4 的 DEGs 中特异性鉴定出了 7 个抗氧化活性基因。随后的实验证实，HK∆4 比 C-00 更能抵抗低浓度的氧化应激。此外，通过 1）对 DEGs 数量、GO 富集术语、呈上升趋势的聚类中的 DEGs 以及 2）对与渗透适应和毒性相关的一些 DEGs 的表达模式的分析，结果表明 C-00 感染的变化主要发生在早期和中期，而 HK∆4 感染的变化主要发生在晚期。我们的结果首次揭示了 AlHK1 调控的长交链孢菌的致病机制，并为真菌-植物相互作用提供了有用的见解。
