IJMS, Vol. 26, Pages 11830: Mitogenome of Medicago lupulina L. Cultivar-Population VIK32, Line MlS-1: Dynamic Structural Organization and Foreign Sequences

International Journal of Molecular Sciences doi: 10.3390/ijms262411830

Authors:
Maria E. Vladimirova
Marina L. Roumiantseva
Alla S. Saksaganskaia
Alexandra P. Kozlova
Victoria S. Muntyan
Sergey P. Gaponov
Andrey P. Yurkov
Vladimir A. Zhukov
Mikhail P. Grudinin

This study presents the complete assembly and analysis of the mitochondrial genome (mitogenome) of Medicago lupulina L. var. vulgaris Koch, cultivar-population VIK32, line MlS-1, which forms an effective symbiosis not only with arbuscular mycorrhiza but also with the root nodule bacteria Sinorhizobium meliloti. The assembly, generated using a hybrid sequencing approach, revealed sequences of putative horizontal origin. These include a highly conserved open reading frame (ORF), orf279, encoding a protein structurally homologous to maturase K, yet bearing remote similarity to bacterial reverse transcriptases and CRISPR-associated proteins. We also identified sequences homologous to mitovirus RNA-dependent RNA polymerases and a fragment of the chloroplast 23S ribosomal RNA (rRNA), suggesting historical gene transfers from viruses and plastids. This work establishes a foundation for investigating the role of mitochondrial genome variation in key plant’s phenotypic traits, such as the enhanced responsiveness to arbuscular mycorrhiza observed in this agronomically valuable line.

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Maria E. Vladimirova www.mdpi.com