The proposed role of MSL-lncRNAs in causing sex lability of female poplars

Abstract

Labile sex expression is frequently observed in dioecious plants, but the underlying genetic mechanism remains largely unknown. Sex plasticity is also observed in many Populus species. Here we carried out a systematic study on a maleness-promoting gene, MSL, detected in the Populus deltoides genome. Our results showed that both strands of MSL contained multiple cis-activating elements, which generated long non-coding RNAs (lncRNAs) promoting maleness. Although female P. deltoides did not have the male-specific MSL gene, a large number of partial sequences with high sequence similarity to this gene were detected in the female poplar genome. Based on sequence alignment, the MSL sequence could be divided into three partial sequences, and heterologous expression of these partial sequences in Arabidopsis confirmed that they could promote maleness. Since activation of the MSL sequences can only result in female sex lability, we propose that MSL-lncRNAs might play a role in causing sex lability of female poplars.

Acknowledgements

The work was supported by the National Key Research and Development Plan of China (2021YFD2200202), the Natural Science Foundation of China (32071795), and the Key Research and Development Project of Jiangsu Province, China (BE2021366).

Author contributions

T.Y. conceived and designed the research. J.M. and Y.C. performed the experiments. S.W. and Y.Y. analyzed the data. T.Y. and J.M. drafted the manuscript.

Data availability

The genome assembly of P. deltoides is available at https://www.ncbi.nlm.nih.gov/bioproject/PRJNA599215 with accession number PRJNA599215, and that of P. davidiana × P. bolleana is unpublished. lncRNA-seq data for poplar samples are available at https://www.ncbi.nlm.nih.gov/bioproject/PRJNA599218 with accession number PRJNA599218. RNA-seq data for the Arabidopsis samples are available at https://www.ncbi.nlm.nih.gov/bioproject/PRJNA885296 with accession number PRJNA885296.

Conflict of interest

The authors declare that they have no conflicts of interest.

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