Transcriptomic Analysis of Resveratrol and Polydatin Accumulation Associated with Crude Elicitors from the Endophytic...

Resveratrol and its glycoside polydatin are high-value stilbene metabolites with broad pharmacological potential, but their natural accumulation in plants is usually limited. Endophytic fungal elicitation may provide a useful approach for improving the accumulation of these compounds. In this study, three crude elicitors prepared from the endophytic fungus Plectosphaerella sp. J-G was evaluated for its effects on seedling growth and stilbene accumulation in Rumex gmelinii Turcz. ex Ledeb. sterile seedlings. Among the tested elicitor types, concentrations, and treatment durations, the mycelial homogenate elicitor at 250 mg·L⁻¹ for 10 days showed a relatively strong induction effect. Under this condition, the total content of resveratrol and polydatin in roots increased by 272.50% compared with the time-matched 10-day sterile water control, from 750.60 to 2795.97 µg·g⁻¹. This treatment was also accompanied by 22.02% higher plant height and 165.63% greater root fresh weight. Transcriptome sequencing and real-time quantitative PCR validation were used to examine transcriptional changes associated with this response. Eight upregulated genes, including IAA, CYP73A/C4H, LDH, SAUR, STS, AOC3, ADH1, and POD, were potentially associated with precursor supply, stilbene/phenylpropanoid biosynthesis, defense response, and auxin-related growth regulation. Several transcription factor families, such as MYB, AP2/ERF, and WRKY, may also be related to the transcriptional response under J-G crude elicitor treatment. These results suggest that J-G crude elicitor treatment may be a useful induction strategy for increasing resveratrol and polydatin accumulation in RGT sterile seedlings and provide candidate genes for future functional validation.