Integrated Mitochondrial Genome and Transcriptomic Analyses Reveal Long Non-Coding RNAs Associated with Drought Tolerance in Sophora moorcroftiana.

Sophora moorcroftiana is a perennial deciduous dwarf shrub that exhibits remarkable ecological adaptability, including strong drought resistance on the Tibetan Plateau. In this study, the complete mitogenome of S. moorcroftiana was reported and assembled for the first time, representing a circular molecule of 534,205 bp with a GC content of 44.93%. The mitogenome was annotated to include 33 unique protein-coding genes (PCGs), 19 tRNA genes, and three rRNA genes. Phylogenetic and collinearity analyses of the mitogenomes of S. moorcroftiana and related species revealed their evolutionary relationships and a non-conserved structure. The codon usage of the PCGs and 166 simple sequence repeats was also analyzed. Conjoint analysis of the transcriptome and mitogenome identified 587 RNA editing sites across 33 PCGs, with 14 genes significantly induced in the roots under drought treatment. Moreover, the levels of proline, soluble sugar, soluble protein, and peroxidase activity were significantly elevated in S. moorcroftiana roots subjected to different PEG6000 concentrations. These findings provide valuable insights into the molecular mechanisms underlying drought responses and offer genetic resources for improving drought resistance in S. moorcroftiana.