Full-length transcriptome sequencing in garlic identifies AsMYB4 as a candidate regulator of flavonoid metabolism and male sterility

Garlic ( Allium sativum L.) is crop of substantial economic value cultivated globally, yet the molecular basis underlying its reproductive development remains poorly understood. Here, we generated a comprehensive full-length garlic transcriptome using PacBio single-molecule real-time sequencing and identified 13,260 high-quality isoforms. Using this resource, we characterized AsMYB4 , an R2R3-MYB transcription factor. Heterologous overexpression of AsMYB4 in Arabidopsis thaliana repressed flavonoid biosynthesis and impaired filament elongation, reduced pollen viability, and decreased fertility without detectably affecting female reproductive function. In stamens, AsMYB4 overexpression suppressed phenylpropanoid-flavonoid metabolism and altered auxin accumulation and signaling, supporting an association between secondary metabolism and hormonal regulation during male reproductive development. Together, these findings expand the transcriptomic resources available for garlic and identify AsMYB4 as a candidate regulator of flavonoid metabolism and male fertility.