Unravelling the regulatory network involved in heat-stress tolerance of potato plants (Pot-HotNet)

马铃薯（Solanum tuberosum）是世界上最重要的农作物之一。由于其相对容易种植和马铃薯块茎的高营养价值，其受欢迎程度稳步上升。然而，已经略微升高的温度对马铃薯块茎形成、产量和质量具有强烈的负面影响。此外，在中欧，预计马铃薯生长季节温暖期的频率较高，这表明迫切需要培育新的耐热品种，以确保产量稳定。更好地理解潜在的分子机制将为这些改进奠定基础。在以前的研究中，我们分析了敏感品种对温度升高的生理，代谢和分子变化，并确定了可能有助于增加温度适应的过程。在拟议的项目中，我们将探索欧洲品种的广谱，以阐明赋予耐热性的分子机制和调控网络。为此，我们计划在控制（20°C）和高温（30°C）下种植200种不同的（育种者选择的）马铃薯品种，并监测表型，形态和生化变化，以便根据其反应模式对基因型进行分组。初步试验表明，热介导的茎长增加与块茎产量呈负相关。芽长是一个容易确定的参数，将用于全基因组关联研究（GWAS）。为了促进这一点，所有栽培品种将序列（GBS）检测等位基因，对应于热胁迫耐受性。到目前为止，大多数GWAS是在二倍体物种中进行的。在这里，我们将使用和发展这种方法的四倍体马铃薯作物。本实验室已建立了相应的生物信息学工具。六个品种的试点实验揭示了适当的测序深度和变异性。除此之外，基因分型的目的是通过RNA测序来研究对比基因型中的转录变化，以鉴定在敏感和耐受品种中表达不同的基因。此外，转录组数据将允许分析先前鉴定的过程中基因表达的变化。此外，它们将使我们能够证明等位基因变异是否反映在转录水平上，从而缩小候选基因。为了检测基因组-转录组-表型组相互作用，所有数据将整合到网络分析中。候选基因将被独立验证，随后进行更详细的表征，并用于开发适合育种计划的诊断标记。

Potato (Solanum tuberosum) is one of the most important crops worldwide. Its popularity increases steadily due to its relatively easy cultivation and the high nutritional value of potato tubers. However, already slightly elevated temperatures have a strong negative impact on potato tuber formation, yield and quality. Also in Central Europe a higher frequency of warm periods is expected during the growing season of potato demonstrating that there is is an urgent need to breed new heat-stress tolerant cultivars to ensure yield stability. A better understanding of underlying molecular mechanisms will build the basis for these improvements. In previous studies, we analyzed the physiological, metabolic and molecular changes in response to elevated temperatures in a sensitive cultivar and identified processes that might contribute to increased temperature adaptation. Within the proposed project we will explore the broad spectrum of European cultivars to elucidate the molecular mechanisms and regulatory networks which confer heat tolerance. To this end, we plan to grow 200 different (breeder-selected) potato cultivars under control (20°C) and elevated temperatures (30°C) and to monitor phenotypic, morphological and biochemical changes allowing to group genotypes based on their response pattern. Preliminary experiments showed that the heat-mediated increase in shoot length negatively correlates with tuber yield. Shoot length is an easy to determine parameter which will be used for a genome-wide association study (GWAS). To facilitate this, all cultivars will be sequences (GBS) to detect alleles that correspond with heat stress tolerance. So far, most GWAS were performed in diploid species. Here, we will use and develop this approach for the tetraploid potato crop. Corresponding bioinformatic tools have been established in our lab. A pilot experiment with six cultivars revealed an appropriate sequencing depth and variability. Beside the genotyping will aim at investigating transcriptional changes in contrasting genotypes by RNA sequencing to identify genes that differ in their expression in sensitive and tolerant varieties. Furthermore, the transcriptome data will permit to analyze changes in gene expression in previously identified processes. Moreover, they will allow us to prove whether allelic variance is reflected at transcriptional level and thereby to narrow down candidate genes. In order to detect genome- transcriptome-phenome interactions all data will be integrated in a network analysis. Candidate genes will be verified independently and subsequently characterized in greater detail and used to develop diagnostic markers suitable for breeding programs.