Engineered hypermutation adapts cyanobacterial photosynthesis to combined high light and high temperature stress.

Huili Sun, Guodong Luan, Yifan Ma, Wenjing Lou, Rongze Chen, Dandan Feng, Shanshan Zhang, Jiahui Sun, Xuefeng Lu

Nature communications 2023 Mar 04

filter terms:

Photosynthesis can be impaired by combined high light and high temperature (HLHT) stress. Obtaining HLHT tolerant photoautotrophs is laborious and time-consuming, and in most cases the underlying molecular mechanisms remain unclear. Here, we increase the mutation rates of cyanobacterium Synechococcus elongatus PCC 7942 by three orders of magnitude through combinatory perturbations of the genetic fidelity machinery and cultivation environment. Utilizing the hypermutation system, we isolate Synechococcus mutants with improved HLHT tolerance and identify genome mutations contributing to the adaptation process. A specific mutation located in the upstream non-coding region of the gene encoding a shikimate kinase results in enhanced expression of this gene. Overexpression of the shikimate kinase encoding gene in both Synechococcus and Synechocystis leads to improved HLHT tolerance. Transcriptome analysis indicates that the mutation remodels the photosynthetic chain and metabolism network in Synechococcus. Thus, mutations identified by the hypermutation system are useful for engineering cyanobacteria with improved HLHT tolerance. © 2023. The Author(s).

Citation

Huili Sun, Guodong Luan, Yifan Ma, Wenjing Lou, Rongze Chen, Dandan Feng, Shanshan Zhang, Jiahui Sun, Xuefeng Lu. Engineered hypermutation adapts cyanobacterial photosynthesis to combined high light and high temperature stress. Nature communications. 2023 Mar 04;14(1):1238