Chloroplast C-to-U editing, regulated by a PPR protein BoYgl-2, is important for chlorophyll biosynthesis in cabbage

Abstract

Leaf color is an important agronomic trait in cabbage ( Brassica oleracea L. var. capitata ), but the detailed mechanism underlying leaf color formation remains unclear. In this study, we characterized a Brassica oleracea yellow-green leaf 2 ( BoYgl-2 ) mutant 4036Y, which has significantly reduced chlorophyll content and abnormal chloroplasts during early leaf development. Genetic analysis revealed that the yellow-green leaf trait is controlled by a single recessive gene. Map-based cloning revealed that BoYgl-2 encodes a novel nuclear-targeted P-type PPR protein, which is absent in the 4036Y mutant. Functional complementation showed that BoYgl-2 from the normal-green leaf 4036G can rescue the yellow-green leaf phenotype of 4036Y. The C-to-U editing efficiency and expression levels of atpF, rps14, petL and ndhD were significantly reduced in 4036Y than that in 4036G, and significantly increased in BoYgl-2 overexpression lines than that in 4036Y. The expression levels of many plastid- and nuclear-encoded genes associated with chloroplast development in BoYgl-2 mutant were also significantly altered. These results suggest that BoYgl-2 participates in chloroplast C-to-U editing and development, which provides rare insight into the molecular mechanism underlying leaf color formation in cabbage.

Acknowledgments

This work was supported by a grant from the National Natural Science Foundation of China (31872948).

Author Contributions

X.H. and Y.Z. conceived and designed the experiments. B.Z., Y.W., and S.L. performed the experiments and analyzed the data. B.Z. wrote the manuscript. X.H. and Y.Z. revised the manuscript. W.R. conducted the expression analysis. L.Y., M.Z., H.L., Y.W., and J.J. provided the valuable suggestions on the manuscript. All authors read and approved the manuscript.

Data Availability

All the data generated or analyzed in this study are included in this published article and its supplementary information files. All the sequence data of the present study have been deposited in the NCBI Sequence Read Archive (SRA) database under BioProject PRJNA1015626.

Conflict of Interest statement

The authors declare that they have no competing interests.

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