van Rooijen Roxanne, Aarts Mark G M, Harbinson Jeremy
Laboratory of Genetics (R.v.R., M.G.M.A.) and Horticulture and Product Physiology (J.H.), Wageningen University, 6708 PB Wageningen, The Netherlands; andBioSolar Cells, 6700 AB Wageningen, The Netherlands (R.v.R., J.H.).
Laboratory of Genetics (R.v.R., M.G.M.A.) and Horticulture and Product Physiology (J.H.), Wageningen University, 6708 PB Wageningen, The Netherlands; andBioSolar Cells, 6700 AB Wageningen, The Netherlands (R.v.R., J.H.)
Plant Physiol. 2015 Apr;167(4):1412-29. doi: 10.1104/pp.114.252239. Epub 2015 Feb 10.
Plants are known to be able to acclimate their photosynthesis to the level of irradiance. Here, we present the analysis of natural genetic variation for photosynthetic light use efficiency (ΦPSII) in response to five light environments among 12 genetically diverse Arabidopsis (Arabidopsis thaliana) accessions. We measured the acclimation of ΦPSII to constant growth irradiances of four different levels (100, 200, 400, and 600 µmol m(-2) s(-1)) by imaging chlorophyll fluorescence after 24 d of growth and compared these results with acclimation of ΦPSII to a step-wise change in irradiance where the growth irradiance was increased from 100 to 600 µmol m(-2) s(-1) after 24 d of growth. Genotypic variation for ΦPSII is shown by calculating heritability for the short-term ΦPSII response to different irradiance levels as well as for the relation of ΦPSII measured at light saturation (a measure of photosynthetic capacity) to growth irradiance level and for the kinetics of the response to a step-wise increase in irradiance from 100 to 600 µmol m(-2) s(-1). A genome-wide association study for ΦPSII measured 1 h after a step-wise increase in irradiance identified several new candidate genes controlling this trait. In conclusion, the different photosynthetic responses to a changing light environment displayed by different Arabidopsis accessions are due to genetic differences, and we have identified candidate genes for the photosynthetic response to an irradiance change. The genetic variation for photosynthetic acclimation to irradiance found in this study will allow future identification and analysis of the causal genes for the regulation of ΦPSII in plants.
众所周知，植物能够使其光合作用适应光照强度水平。在此，我们展示了对12个遗传多样性不同的拟南芥（Arabidopsis thaliana）生态型在五种光照环境下光合光利用效率（ΦPSII）的自然遗传变异分析。我们通过在生长24天后成像叶绿素荧光来测量ΦPSII对四种不同水平（100、200、400和600 μmol m(-2) s(-1)）的恒定生长光照强度的适应性，并将这些结果与ΦPSII对光照强度逐步变化的适应性进行比较，其中生长光照强度在生长24天后从100增加到600 μmol m(-2) s(-1)。通过计算短期ΦPSII对不同光照强度水平的响应的遗传力，以及在光饱和时测量的ΦPSII（光合能力的一种度量）与生长光照强度水平的关系，以及对光照强度从100逐步增加到600 μmol m(-2) s(-1)的响应动力学，来显示ΦPSII的基因型变异。一项对光照强度逐步增加1小时后测量的ΦPSII的全基因组关联研究确定了几个控制该性状的新候选基因。总之，不同拟南芥生态型对变化的光照环境表现出的不同光合响应是由于遗传差异，并且我们已经确定了光合对光照强度变化响应的候选基因。本研究中发现的光合对光照强度适应的遗传变异将有助于未来鉴定和分析植物中调节ΦPSII的因果基因。
