Abstract
Fusarium verticillioides is the most commonly reported fungal species responsible for ear rot of maize which substantially reduces grain yield. It also results in a substantial accumulation of mycotoxins that give rise to toxic response when ingested by animals and humans. For inefficient control by chemical and agronomic measures, it thus becomes more desirable to select more resistant varieties. However, the molecular mechanisms underlying the infection process remain poorly understood, which hampers the application of quantitative resistance in breeding programs. Here, we reveal the disease-resistance mechanism of the maize inbred line of BT-1 which displays high resistance to ear rot using RNA high throughput sequencing. By analyzing RNA-seq data from the BT-1 kernels before and after F. verticillioides inoculation, we found that transcript levels of genes associated with key pathways are dramatically changed compared with the control treatment. Differential gene expression in ear rot resistant and susceptible maize was confirmed by RNA microarray and qRT-PCR analyses. Further investigation suggests that the small heat shock protein family, some secondary metabolites, and the signaling pathways of abscisic acid, jasmonic acid, or salicylic acids (SA) may be involved in the pathogen-associated molecular pattern-triggered immunity against F. verticillioides. These data will not only provide new insights into the molecular resistant mechanisms against fungi invading, but may also result in the identification of key molecular factors associated with ear rot resistance in maize.
Highlights
Fusarium verticillioides is an important pathogenic fungus, which causes stalk rot and ear rot in maize (White, 1999)
The results showed that the pattern-triggered immunity (PTI) process and signal pathways of abscisic acid (ABA), jasmonic acid (JA), and salicylic acids (SA) were respectively activated in the later stage after inoculation with BT-1, and that sHSP families as well as some secondary metabolites may be involved in this process, and leading to variable resistance levels in different maize materials
Four genes were selected for further analysis, in which GRMZM5G847466 (CaM) and GRMZM2G449681 (FPKM53) are associated with the PTI mechanism, and another two genes of GRMZM2G010855 for protein phosphatase 2C and GRMZM5G857693 for HSP20 are involved in ABA and sHSP pathways, respectively
Summary
Fusarium verticillioides is an important pathogenic fungus, which causes stalk rot and ear rot in maize (White, 1999). Symptoms of ear rot are related to genotype, environment and the degree of infection (Bacon et al, 2008). Another by-product of F. verticillioides infection is the production of deoxynivalenol and fumonisin, which causes food poisoning and cancer. Chemical and agronomic methods preventing ear rot are not very efficient because F. verticillioides can systemically infect maize without producing symptoms and can spread from seeds to kernels For these reasons, host resistance is the most reliable and economical way to reduce the damage caused by ear rot
Sign-in/Register to view highlights & summary 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.
