Isolation and molecular characterisation of Dunaliella tertiolecta with truncated light-harvesting antenna for enhanced photosynthetic efficiency
Isolation and molecular characterisation of Dunaliella tertiolecta with truncated light-harvesting antenna for enhanced photosynthetic efficiency
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DOI：
10.1016/j.algal.2020.101917
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发表时间：
2020-06-01
影响因子：
5.1
通讯作者：
Bibby, T. S.
中科院分区：
文献类型：
--
作者：
Johansson, S. A.;Stephenson, P. G.;Bibby, T. S.
在这里，我们报告了一个高通量的选择协议，使用随机诱变和活单细胞分选分离细胞系的藻类杜氏藻tertiolecta叶绿素含量降低，目的是优化天线的大小，提高光合效率的发展。已经分离出两种有前途的细胞系（Ica 1和Ica 2），其显示截短的捕光天线，并因此通过增加光合作用变得饱和的光强度（I-s）来提高光合能量转换效率。Ica 1和Ica 2显着不同：Ica 2表型保留了改变其天线大小的能力，以响应不同的光强度，而Ica 1似乎已经失去了这种能力，并被“锁定”到一个截断的天线和高光表型。尽管有这些明显的差异，转录组学分析表明，差异表达的核编码的光合作用基因的表达谱在Ica 1和Ica 2中是相似的，这可能表明光合作用调控中的潜在突变引起了观察到的表型变化，而不是影响光合装置特定组分的突变。这里提出的方法的组合提供了从任何微藻物种大幅提高光合效率的能力，而不管其在遗传上的特征或用于合理工程的分子工具的可用性。因此，它提供了开始利用微藻巨大的自然多样性来提高生物质产量的潜力。
Here we report the development of a high-throughput selection protocol using random mutagenesis and live single-cell sorting to isolate cell lines from the algae Dunaliella tertiolecta with reduced chlorophyll content, with the aim to optimise the antenna size for increased photosynthetic efficiency. Two promising cell lines (Ica1 and Ica2) have been isolated that display a truncated light-harvesting antenna, and hence improved photosynthetic energy conversion efficiency by increasing the light intensity at which photosynthesis becomes saturated (I-s). Ica1 and Ica2 differ significantly: the Ica2 phenotype retains an ability to alter its antenna size in response to varying light intensity, whereas Ica1 appears to have lost this ability and is 'locked' to a truncated antenna and high-light phenotype. Despite these clear differences, transcriptomic analysis shows that the expression profiles for differentially expressed nuclear-encoded photosynthetic genes is similar in both Ica1 and Ica2, possibly suggesting underlying mutations in the regulation of photosynthesis are causing the observed changes in phenotype rather than mutations impacting specific components of the photosynthetic apparatus. The combination of approaches presented here offer the capacity to substantially improve photosynthetic efficiency from any microalgal species irrespective of the extent to which it has been characterised genetically or the availability of molecular tools for rational engineering. It thus offers the potential to begin to exploit the huge natural diversity of microalgae for enhanced biomass production.