1. Identification and application of a candidate gene AhAftr1 for aflatoxin production resistance in peanut seed (Arachis hypogaea L.).
- Author
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Yu, Bolun, Liu, Nian, Huang, Li, Luo, Huaiyong, Zhou, Xiaojing, Lei, Yong, Yan, Liying, Wang, Xin, Chen, Weigang, Kang, Yanping, Ding, Yingbin, Jin, Gaorui, Pandey, Manish K., Janila, Pasupuleti, Kishan Sudini, Hari, Varshney, Rajeev K., Jiang, Huifang, Liu, Shengyi, and Liao, Boshou
- Abstract
[Display omitted] • A major QTL for aflatoxin production resistance was identified in a 1.98 Mbp genomic region by both NGS-based QTL-seq approach and genetic linkage analysis. • A gene namely AhAftr1 , annotated as "NB-LRRs protein gene" with structural variation (SV) in the LRRs domain between parental lines was identified by fine-mapping using a secondary segregation mapping population. • Transgenic experiments confirmed that the SV of AhAftr1 confers aflatoxin production resistance. • RNA-Seq and differential gene expression analysis indicated that AhAftr1 might be involved in disease resistance via the ETI pathway. • Thirty-six lines were identified from a special panel of germplasm accessions and breeding lines by using AFTR.Del.A07, which was developed based on the SV, and their aflatoxin content were decreased by over 77.67% compared to the susceptible control Zhonghua12. Peanut is susceptible to infection of Aspergillus fungi and conducive to aflatoxin contamination, hence developing aflatoxin-resistant variety is highly meaningful. Identifying functional genes or loci conferring aflatoxin resistance and molecular diagnostic marker are crucial for peanut breeding. This work aims to (1) identify candidate gene for aflatoxin production resistance, (2) reveal the related resistance mechanism, and (3) develop diagnostic marker for resistance breeding program. Resistance to aflatoxin production in a recombined inbred line (RIL) population derived from a high-yielding variety Xuhua13 crossed with an aflatoxin-resistant genotype Zhonghua 6 was evaluated under artificial inoculation for three consecutive years. Both genetic linkage analysis and QTL-seq were conducted for QTL mapping. The candidate gene was further fine-mapped using a secondary segregation mapping population and validated by transgenic experiments. RNA-Seq analysis among resistant and susceptible RILs was used to reveal the resistance pathway for the candidate genes. The major effect QTL qAFTRA07.1 for aflatoxin production resistance was mapped to a 1.98 Mbp interval. A gene, AhAftr1 (Arachis hypogaea Aflatoxin resistance 1), was detected structure variation (SV) in leucine rich repeat (LRR) domain of its production, and involved in disease resistance response through the effector-triggered immunity (ETI) pathway. Transgenic plants with overexpression of AhAftr1 (ZH6) exhibited 57.3% aflatoxin reduction compared to that of AhAftr1 (XH13). A molecular diagnostic marker AFTR.Del.A07 was developed based on the SV. Thirty-six lines, with aflatoxin content decrease by over 77.67% compared to the susceptible control Zhonghua12 (ZH12), were identified from a panel of peanut germplasm accessions and breeding lines through using AFTR.Del.A07. Our findings would provide insights of aflatoxin production resistance mechanisms and laid meaningful foundation for further breeding programs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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