Abstract
Botrytis cinerea is an important necrotrophic fungal pathogen with a broad host range and the ability to causing great economic losses in cucumber. However, the resistance mechanism against this pathogen in cucumber was not well understood. In this study, the microscopic observation of the spore growth, redox status measurements and transcriptome analysis were carried out after Botrytis cinerea infection in the resistant genotype No.26 and its susceptible mutant 26M. Results revealed shorter hypha, lower rate of spore germination, less acceleration of H2O2, O2 -, and lower total glutathione content (GSH+GSSG) in No.26 than that in 26M, which were identified by the staining result of DAB and NBT. Transcriptome data showed that after pathogen infection, a total of 3901 and 789 different expression genes (DEGs) were identified in No.26 and 26M respectively. These DEGs were highly enriched in redox regulation pathway, hormone signaling pathway and plant-pathogen interaction pathway. The glutathione S-transferase genes, putative peroxidase gene, and NADPH oxidase were up-regulated in No.26 whereas these genes changed little in 26M after Botrytis cinerea infection. Jasmonic acid and ethylene biosynthesis and signaling pathways were distinctively activated in No.26 comparing with 26M upon infection. Much more plant defense related genes including mitogen-activated protein kinases, calmodulin, calmodulin-like protein, calcium-dependent protein kinase, and WRKY transcription factor were induced in No.26 than 26M after pathogen infection. Finally, a model was established which elucidated the resistance difference between resistant cucumber genotype and susceptible mutant after B. cinerea infection.
Highlights
Gray mold caused by B. cinerea, which is a plant fungal pathogen with a typically necrotrophic lifestyle
Csa7G049170 and Csa2G406060 WRKY genes had an opposite expression patterns in both cucumber genotypes, which were induced in No.26 and down-regulated in 26M respectively. These results showed that WRKY transcription factor might be a key factor in resistance to B. cinerea, which may regulated the gray mold either negatively or positively in cucumber
The role of reactive oxygen species (ROS), jasmonic acid (JA), and ET in response to necrotrophic pathogens was revealed combined ROS content with differential expression genes involved in hormonal synthesis and signal transduction (Figure 8)
Summary
Gray mold caused by B. cinerea, which is a plant fungal pathogen with a typically necrotrophic lifestyle. To increase the production and economic efficiency, most of the farmers grow their vegetables continuously in greenhouse that may cause continuous cropping obstacle and the accumulation of pathogens such as B. cinerea (Li et al, 2016). High humidity with 20–30°C temperature inside the greenhouse is suitable for the epidemic B. cinerea (Kozhar and Peever, 2018). This fungus can kill the host cells through the production of toxins and acquire nutrients from death cells, a parasitic relationship starts with infection process
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
