A GATA transcription factor modulates melatonin production and drought resistance in Hypericum perforatum

Hypericum perforatum is an important medicinal plant rich in melatonin, with both ecological and pharmacological value. However, the light-related transcriptional regulatory mechanisms underlying its melatonin biosynthetic pathway remain unclear. This study identified the GATA transcription factor HpGATA7 as a key upstream regulator of melatonin synthesis. This factor shows high similarity to light-responsive class A GATA proteins. HpGATA7 is localized in the nucleus, exhibits transcriptional activation activity, and its expression is rapidly induced by light and significantly upregulated under various abiotic stresses. HpGATA7 directly recognizes the GATA motif within the HpSNAT1 promoter and enhances its transcription. Overexpression of HpGATA7 significantly upregulates HpSNAT1 expression and promotes melatonin accumulation, while the overexpression lines also demonstrate enhanced drought tolerance. This study identifies a novel regulatory module where HpGATA7 activates HpSNAT1 to enhance melatonin biosynthesis and drought resistance in H. perforatum through targeted activation. These findings elucidate transcriptional control of secondary metabolism and propose HpGATA7 as a key target for engineering improved melatonin production and stress tolerance in medicinal plants. • HpGATA7 is identified as a GATA transcription factor that directly binds to and activates the promoter of the melatonin synthesis gene HpSNAT1. • Overexpression of HpGATA7 significantly increases melatonin biosynthesis in Hypericum perforatum. • HpGATA7 improves drought tolerance in plants, associated with enhanced antioxidant enzyme activity and reduced oxidative stress. • This study reveals a novel transcriptional regulatory mechanism linking secondary metabolism and abiotic stress adaptation in a medicinal plant.