Brassica evolution of essential BnaFtsH1 genes involved in the PSII repair cycle and loss of FtsH5. (February 2022)

• Record Type: Journal Article
• Authors: Xu, Kai; Song, Jurong; Wu, Yujin; Zhuo, Chenjian; Wen, Jing; Yi, Bin; Ma, Chaozhi; Shen, Jinxiong; Fu, Tingdong; Tu, Jinxing
• Is Part Of: Plant science. Volume 315(2022)
• Publication Date: 2022-02
• Subjects: Brassica napus -- FtsH1 -- PSII repair cycle -- Biomass accumulation -- Phylogenetic analysis -- Gene evolution; Botany -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1016/j.plantsci.2021.111128
• Languages: English
• ISSNs: 0168-9452

Abstract

Highlights: Deletion of BnaC06.FtsH1 and the transposon insertion of BnaA07.FtsH1 led to the lethal phenotype of the mutant 7−521Y. Gene silencing of BnaFtsH1 genes in Westar confers lethal phenotype, FtsH1 copy number affects biomass accumulation . BnaC06.FtsH1 may restore the photosynthetic system by promoting the expression of photosynthetic-related genes. Phylogenetic analyses based on 15 cruciferous species, revealed that Brassica alone had lost FtsH5 during evolution. Abstract: The PSII repair cycle is an important part of photosynthesis and is essential for high photosynthetic efficiency. The study of essential genes in Brassica napus provides significant potential for the improvement of gene editing technology and molecular breeding design. Previously, we identified a B. napus lethal mutant (7−521Y), which was controlled by two recessive genes ( cyd1 and cyd2 ). BnaC06.FtsH1 was identified as a CYD1 target gene through functional verification. In the present study, we employed fine-mapping, genetic complementation, and CRISPR/Cas9 experiments to identify BnaA07.FtsH1 as the target gene of CYD2, functioning similarly to BnaC06.FtsH1 . By analyzing CRISPR/Cas9 T1 generation plants of the Westar variety, we found that the copy number of FtsH1 was positively correlated with its biomass accumulation. Transcriptome analysis of cotyledons revealed differences in the expression of photosynthesis antenna and structural proteins between the mutant and complementary seedlings. Phylogenetic and chromosome linear analyses, based on 15 sequenced cruciferous species, revealed that Brassica alone had lost FtsH5 during evolution. This may be related to the fact that FtsH5 was located at the end of chromosome ABK8 in the ancestor species. Cloning and identification of BnaFtsH1s provide a deeper understanding of PSII repair cycle mechanisms and offer new insights for the improvement of photosynthetic efficiency and molecular breeding design in B. napus.