Shokat Sajid, Novák Ondřej, Široká Jitka, Singh Sukhwinder, Gill Kulvinder Singh, Roitsch Thomas, Großkinsky Dominik K, Liu Fulai
Crop science, Department of Plant and Environmental Sciences, University of Copenhagen, Højbakkegård Allé, Taastrup, Denmark.
Wheat Breeding Group, Plant Breeding and Genetics Division, Nuclear Institute for Agriculture and Biology, Faisalabad, Pakistan.
J Exp Bot. 2021 May 29. doi: 10.1093/jxb/erab247.
Two wheat genotypes forming high and low biomass (HB and LB), exhibiting differential expression of an isoflavone reductase-like (IRL) gene, and resulting in contrasting grain yield under heat stress field conditions, were analyzed in detail for their responses under controlled heat and elevated CO2 conditions. Significant differences in IRL expression between the two lines were hypothesized to be the basis of their differential performance under the tested conditions and their stress tolerance potential. By a holistic approach integrating advanced cell physiological phenotyping of the antioxidative and phytohormone system in spikes and leaves with measurements of ecophysiological and agronomic traits, the genetic differences of the genotypes in IRL expression were assessed. In response to heat and elevated CO2, the two genotypes showed opposite regulation of IRL expression, which was associated with cytokinin concentration, total flavonoid contents, activity of superoxide dismutase, antioxidant capacity and photosynthetic rate in leaves and cytokinin concentration and ascorbate peroxidase activity in spikes. Our study showed that IRL expression is associated with wheat yield performance under heat stress at anthesis, mediated by diverse physiological mechanisms. Hence, based on our results, the IRL gene is a promising candidate for developing genetic markers for breeding heat-tolerant wheat.
对两种形成高生物量和低生物量（HB和LB）的小麦基因型进行了详细分析，它们的异黄酮还原酶样（IRL）基因表达存在差异，在热胁迫田间条件下导致了截然不同的籽粒产量。研究了它们在可控热和高二氧化碳条件下的反应。据推测，这两个品系间IRL表达的显著差异是它们在测试条件下表现不同及其胁迫耐受潜力的基础。通过一种整体方法，将穗部和叶片中抗氧化和植物激素系统的先进细胞生理表型分析与生态生理和农艺性状的测量相结合，评估了基因型在IRL表达方面的遗传差异。响应热和高二氧化碳，这两个基因型显示出IRL表达的相反调控，这与叶片中的细胞分裂素浓度、总黄酮含量、超氧化物歧化酶活性、抗氧化能力和光合速率以及穗部中的细胞分裂素浓度和抗坏血酸过氧化物酶活性有关。我们的研究表明，IRL表达与花期热胁迫下的小麦产量表现相关，由多种生理机制介导。因此，基于我们的结果，IRL基因是开发耐热小麦育种遗传标记的一个有前景的候选基因。
