Spinach (Spinacia oleracea L.), a globally consumed, nutrient-dense vegetable, contains diverse vitamins and minerals. However, elevated temperatures can constrain yield by interrupting leaf development and photosynthetic efficiency. The mitochondrial transcription termination factor (mTERF) family, which regulates organellar gene expression, plays crucial roles in plant growth and photosynthetic regulation. Thus, characterization of the spinach mTERF (SomTERF) family is critical for elucidating thermotolerance mechanisms in this crop. In this study, we systematically identified 31 SomTERF genes from the spinach genome, which are distributed across five chromosomes and nine unassembled genomic scaffolds. Subcellular localization predictions indicated that these proteins predominantly target chloroplasts and mitochondria. Conserved domain analyses confirmed that all SomTERF proteins possess canonical mTERF domains and ten conserved motifs. Phylogenetic clustering segregated these proteins into nine distinct subgroups (I–IX), with significant divergence observed in gene copy numbers among subgroups. Cis-element screening identified an abundance of heat-, cold-, and hormone-responsive motifs within SomTERF promoter regions. Notably, seven members (including SomTERF5) exhibited pronounced enrichment of heat shock elements (HSEs). Organ-specific expression profiling revealed preferential leaf expression of these seven genes. Comparative RT-qPCR in heat-sensitive (Sp73) and heat-tolerant (Sp75) cultivars under thermal stress demonstrated genotype-dependent expression dynamics. Functional validation of SomTERF5 was achieved through cloning, and transgenic Arabidopsis overexpressing SomTERF5 showed significantly enhanced thermotolerance, as evidenced by improved survival rates following heat treatment. Yeast two-hybrid (Y2H) assays further revealed physical interaction between SomTERF5 and SopTAC2. This study provides a comprehensive foundation for understanding mTERF-mediated developmental regulation and advanced molecular breeding strategies for developing heat-resilient spinach varieties.

Soybean relies on symbiotic nitrogen fixation (SNF) to support sustainable agriculture. In this study, we conducted a comprehensive analysis of the GmMYB transcription factor subfamily 20, with a focus on GmMYB62a and GmMYB62b. Phylogenetic and structural analyses revealed that these genes are evolutionarily conserved among legumes and possess distinct domain architectures. Expression profiling and GUS staining showed that GmMYB62a and GmMYB62b are constitutively expressed in nodules. Functional analyses revealed that loss of GmMYB62s function significantly reduced nodule density, while overexpression promoted nodulation. Transcriptomic analysis (RNA-seq) further demonstrated that GmMYB62s regulate key pathways, including hormone signaling, immune responses, and cell wall metabolism, thereby coordinating symbiotic interactions. Collectively, our findings identify GmMYB62a and GmMYB62b as critical molecular regulators of nodulation in soybean, providing promising targets for improving symbiotic nitrogen fixation efficiency in legume crops.