Quantitative trait loci mapping and transcriptome analysis reveal candidate genes regulating the response to ozone in Arabidopsis thaliana

The formation of Reactive oxygen species (ROS) has been detected in all cellular departments and even in apoplastic space of plants. As multifaceted molecule, ROS are known to accumulate in response to various stresses, and ROS burst accompanied with transcriptomic reprogramming leading to defense response or programmed cell death. Acute ozone exposure has been used as a noninvasive tool to study ROS burst induced defense response and cell death for a long time. Moreover the variation of ozone sensitivity in different Arabidopsis accessions highlights the flexibility of complex genetic architecture to adapt to specific stresses. In this study, we combine classic Quantitative Trait Loci (QTL) mapping and RNA-seq to identify the cause QTLs and potential gene candidates in response to ozone. RNA sequencing was performed on both control and ozone treated 3 weeks old accessions C24 (ozone tolerant), Te (ozone sensitive) and on a RIL line CT101 (a hypersensitive line of RIL population from reciprocal cross between C24 and Te), in triplicate. We identified 69 potential genes candidates inside the QTL regions and about 200 potential genes outside QTL region in response to ozone by comparing control to treatment within same genotype or comparing control between genotypes. Overall design: Transcriptome profiling of ozone response using two arabidopsis accessions C24 and Te with different ozone sensitivity

活性氧（Reactive oxygen species, ROS）的形成已在植物的所有细胞区域乃至质外体空间中被检测到。作为一类多功能分子，ROS已知会在响应多种胁迫时积累，且活性氧爆发伴随转录组重编程，进而引发防御反应或程序性细胞死亡。长期以来，急性臭氧暴露被用作非侵入性工具，用以研究由活性氧爆发诱导的防御反应与细胞死亡。此外，不同拟南芥生态型间的臭氧敏感性差异，凸显了复杂遗传结构适应特定胁迫的灵活性。本研究结合经典数量性状位点（Quantitative Trait Loci, QTL）定位技术与RNA测序（RNA-seq），旨在鉴定响应臭氧胁迫的因果QTL及潜在候选基因。我们对3周龄的两个拟南芥生态型——臭氧耐受型C24、臭氧敏感型Te，以及由二者互交得到的重组自交系（Recombinant Inbred Line, RIL）群体中的超敏感株系CT101，分别设置对照组与臭氧处理组，并设置三次生物学重复，进行RNA测序。通过在同一基因型内比较对照组与处理组，或是在不同基因型间比较对照组，我们在QTL区域内鉴定出69个潜在候选基因，在QTL区域外鉴定出约200个响应臭氧胁迫的潜在候选基因。整体实验设计：采用臭氧敏感性存在差异的两个拟南芥生态型C24与Te，开展臭氧响应的转录组谱分析。