Rose Teresa, Wilkinson Mark, Lowe Claudia, Xu Jiemeng, Hughes David, Hassall Kirsty L, Hassani-Pak Keywan, Amberkar Sandeep, Noleto-Dias Clarice, Ward Jane, Heuer Sigrid
Rothamsted Research Harpenden UK.
Institute of Systems, Molecular and Integrative Biology University of Liverpool Liverpool UK.
Plant Environ Interact. 2022 Dec 26;3(6):264-289. doi: 10.1002/pei3.10096. eCollection 2022 Dec.
To prevent yield losses caused by climate change, it is important to identify naturally tolerant genotypes with traits and related pathways that can be targeted for crop improvement. Here we report on the characterization of contrasting vegetative heat tolerance in two UK bread wheat varieties. Under chronic heat stress, the heat-tolerant cultivar Cadenza produced an excessive number of tillers which translated into more spikes and higher grain yield compared to heat-sensitive Paragon. RNAseq and metabolomics analyses revealed that over 5000 genotype-specific genes were differentially expressed, including photosynthesis-related genes, which might explain the observed ability of Cadenza to maintain photosynthetic rate under heat stress. Around 400 genes showed a similar heat-response in both genotypes. Only 71 genes showed a genotype × temperature interaction. As well as known heat-responsive genes such as heat shock proteins (HSPs), several genes that have not been previously linked to the heat response, particularly in wheat, have been identified, including dehydrins, ankyrin-repeat protein-encoding genes, and lipases. Contrary to primary metabolites, secondary metabolites showed a highly differentiated heat response and genotypic differences. These included benzoxazinoid (DIBOA, DIMBOA), and phenylpropanoids and flavonoids with known radical scavenging capacity, which was assessed via the DPPH assay. The most highly heat-induced metabolite was (glycosylated) propanediol, which is widely used in industry as an anti-freeze. To our knowledge, this is the first report on its response to stress in plants. The identified metabolites and candidate genes provide novel targets for the development of heat-tolerant wheat.
为防止气候变化导致产量损失，识别具有可用于作物改良的性状及相关途径的天然耐受基因型非常重要。在此，我们报告了对英国两个面包小麦品种营养期耐热性差异的表征。在长期热胁迫下，耐热品种卡丹察（Cadenza）产生了过多的分蘖，与热敏感品种帕拉贡（Paragon）相比，这转化为更多的穗数和更高的籽粒产量。RNA测序和代谢组学分析表明，超过5000个基因型特异性基因存在差异表达，包括与光合作用相关的基因，这可能解释了卡丹察在热胁迫下维持光合速率的能力。约400个基因在两个基因型中表现出相似的热响应。只有71个基因表现出基因型×温度互作。除了热休克蛋白（HSPs）等已知的热响应基因外，还鉴定出了几个以前未与热响应相关联的基因，特别是在小麦中，包括脱水素、锚蛋白重复序列编码基因和脂肪酶。与初级代谢产物相反，次级代谢产物表现出高度分化的热响应和基因型差异。这些包括具有已知自由基清除能力的苯并恶嗪类（DIBOA、DIMBOA）以及苯丙烷类和黄酮类化合物，通过DPPH法对其进行了评估。受热诱导程度最高的代谢产物是（糖基化）丙二醇，它在工业上广泛用作防冻剂。据我们所知，这是关于其在植物中对胁迫响应的首次报道。鉴定出的代谢产物和候选基因为耐热小麦的培育提供了新的靶点。
