Transcriptional analysis and histochemistry reveal that hypersensitive cell death and H2O2 have crucial roles in the resistance of tea plant (Camellia sinensis (L.) O. Kuntze) to anthracnose. Issue 1 (1st April 2018)

• Record Type: Journal Article
• Authors: Wang, Yuchun; Hao, Xinyuan; Lu, Qinhua; Wang, Lu; Qian, Wenjun; Li, Nana; Ding, Changqing; Wang, Xinchao; Yang, Yajun
• Is Part Of: Horticulture research. Volume 5:Issue 1(2018)
• Publication Date: 2018-04-01
• Subjects: Plant immunity -- Plant stress responses; Horticulture -- Research -- Periodicals; 635.072
• DOI: 10.1038/s41438-018-0025-2
• Languages: English
• ISSNs: 2052-7276

Abstract

Abstract: Anthracnose causes severe losses of tea production in China. Although genes and biological processes involved in anthracnose resistance have been reported in other plants, the molecular response to anthracnose in tea plant is unknown. We used the susceptible tea cultivar Longjing 43 and the resistant cultivar Zhongcha 108 as materials and compared transcriptome changes in the leaves of both cultivars following Colletotrichum fructicola inoculation. In all, 9015 and 8624 genes were differentially expressed between the resistant and susceptible cultivars and their controls (0 h), respectively. In both cultivars, the differentially expressed genes (DEGs) were enriched in 215 pathways, including responses to sugar metabolism, phytohormones, reactive oxygen species (ROS), biotic stimuli and signalling, transmembrane transporter activity, protease activity and signalling receptor activity, but DEG expression levels were higher in Zhongcha 108 than in Longjing 43. Moreover, functional enrichment analysis of the DEGs showed that hydrogen peroxide (H2 O2 ) metabolism, cell death, secondary metabolism, and carbohydrate metabolism are involved in the defence of Zhongcha 108, and 88 key genes were identified. Protein–protein interaction (PPI) network demonstrated that putative mitogen-activated protein kinase (MAPK) cascades are activated by resistance (R) genes and mediate downstream defence responses. Histochemical analysis subsequently validated the strong hypersensitive response (HR) and H2 O2 accumulation that occurred around the hyphal infection sites in Zhongcha 108. Overall, our results indicate that the HR and H2 O2 are critical mechanisms in tea plant defence against anthracnose and may be activated by R genes via MAPK cascades. Plant defence: pathways for tea protection: A comparison of gene activity in resistant and susceptible tea cultivars provides insights into mechanisms of defence against one of the most devastating tea diseases: anthracnose. Tea ( Camellia sinensis ) is an important crop in many tropical countries; however, yields can be devastated by the fungus Colletotrichum, the causal agent of anthracnose. Xinchao Wang and Yajun Yang, of the Chinese Academy of Sciences' Tea Research Institute in Hangzhou, explored the defence response in tea cultivars infected with Colletotrichum . Discrepancies in the genes activated in resistant and susceptible cultivars suggest resistance is mediated by specific molecular signalling pathways, known resistance (R) genes, and involves the production of hydrogen peroxide and initiation of programmed cell death around sites of infection. These mechanisms could be harnessed to develop tea cultivars with greater resistance to anthracnose.