Overexpression of SlGRAS38 in tomato roots accelerates arbuscular mycorrhiza formation

Recent research has highlighted the role of GRAS family transcription factors (TFs) in arbuscular mycorrhizal (AM) formation, particularly in tomato plants. This study conducted a functional analysis of the SCL32 GRAS transcription factor SlGRAS38 during arbuscular mycorrhizal formation in tomatoes, confirming its positive regulatory effect on mycorrhiza formation. Experiments reveal that overexpression of SlGRAS38 accelerates mycorrhizal colonization and enhances nutrient uptake, flowering, and fruit yield. Transcriptomic data indicate that SlGRAS38 may function as a new transcriptional regulator during mycorrhization. SlGRAS38 has previously been described as a transcriptional activator in ripening fruits, and here we demonstrate its regulatory role in mycorrhizal roots, suggesting potential cross-talk between these physiological processes. However, the exact mechanisms remain to be fully understood. Further research is needed to explore the interplay between SlGRAS38's roles in mycorrhization and fruit ripening, and to confirm its interaction within transcriptional complexes critical for arbuscule formation. This study underscores the importance of SlGRAS38 in AM development and opens avenues for future investigations into its multifaceted functions. • The tomato transcription factor SlGRAS38 is a positive regulator of Arbuscular Mycorrhiza (AM). • Ectopic expression of SlGRAS38 positively impacts the symbiotic effectiveness. • SlGRAS38 overexpression in non-mycorrhizal roots triggers transcriptomic alterations in AM-related genes.