Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, VIC, 3010, Australia.
Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, 116 Daley Rd, Canberra, ACT, 2601, Australia.
Theor Appl Genet. 2016 Jul;129(7):1333-1345. doi: 10.1007/s00122-016-2706-2. Epub 2016 Apr 15.
Significant differences in defence pathway-related gene expression were observed among chickpea cultivars following A. rabiei infection. Differential gene expression is indicative of diverse resistances, a theoretical tool for selective breeding. A high number of Ascochyta rabiei pathotypes infecting chickpea in Australia has severely hampered efforts towards breeding for sustained quantitative resistance in chickpea. Breeding for sustained resistance will be aided by detailed knowledge of defence responses to isolates with different aggressiveness. As an initial step, the conserved and differential expressions of a suit of previously characterised genes known to be involved in fungal defence mechanisms were assessed among resistant and susceptible host genotypes following inoculation with high or low aggressive A. rabiei isolates. Using quantitative Real-Time PCR (qRT-PCR), 15 defence-related genes, normalised with two reference genes, were temporally differentially expressed (P < 0.005) as early as 2 h post inoculation of Genesis090 (resistant) or Kaniva (susceptible). The highly aggressive isolate, 09KAL09, induced vastly different expression profiles of eight key defence-related genes among resistant and susceptible genotypes. Six of these same genes were differentially expressed among ten host genotypes, inclusive of the best resistance sources within the Australian chickpea breeding program, indicating potential use for discrimination and selection of resistance "type" in future breeding pursuits.
在豌豆感染 A. rabiei 后，不同品种的豌豆中防御途径相关基因的表达存在显著差异。差异基因表达表明存在不同的抗性，这是选择性育种的理论工具。澳大利亚感染豌豆的 A. rabiei 生理小种数量众多，严重阻碍了豌豆持续定量抗性的培育。详细了解对不同侵袭力的分离物的防御反应，将有助于持续抗性的培育。作为初始步骤，在接种高或低侵袭性 A. rabiei 分离物后，评估了先前鉴定的与真菌防御机制相关的一套保守和差异表达的基因在抗性和敏感宿主基因型中的表达情况。使用定量实时 PCR（qRT-PCR），在 Genesis090（抗性）或 Kaniva（敏感）接种后 2 小时内，15 个防御相关基因就表现出了时间上的差异表达（P<0.005）。高度侵袭性的分离物 09KAL09 在抗性和敏感基因型中诱导了 8 个关键防御相关基因的截然不同的表达谱。这 6 个相同的基因在包括澳大利亚豌豆育种计划中最佳抗性来源的 10 个宿主基因型中存在差异表达，表明在未来的育种研究中，这些基因可能具有用于抗性“类型”的鉴别和选择的潜力。
