Fecha de publicación: -- Fuente: PubMed "essential oil" Pestic Biochem Physiol. 2026 Sep;223:107291. doi: 10.1016/j.pestbp.2026.107291. Epub 2026 Jul 31.ABSTRACTThe plant-derived volatile (E)-2-hexenal is a promising antifungal compound for sustainable crop protection, but green extraction strategies for essential oils enriched in this compound and the molecular basis underlying its accumulation remain insufficiently understood. In this study, we optimized the extraction of Impatiens noli-tangere leaf essential oil, evaluated its antifungal activity, and investigated (E)-2-hexenal biosynthesis using integrated transcriptomic and metabolomic analysis followed by functional validation. An enzymatic pretreatment-microwave-assisted extraction (EP-MAE) process was optimized using Plackett-Burman and Box-Behnken designs, increasing leaf essential oil yield to 4.58 μL/g and enriching (E)-2-hexenal to 51.92%. The EP-MAE oil strongly inhibited Colletotrichum gloeosporioides, with a minimum inhibitory concentration (MIC) of 0.75 μL/mL, whereas authentic (E)-2-hexenal exhibited an MIC of 0.375 μL/mL. Equivalent-concentration analysis supported (E)-2-hexenal as a major contributor to the antifungal activity of the essential oil, while accompanying volatile constituents may provide additional inhibitory effects. At the molecular level, weighted gene co-expression network analysis identified a co-expression module significantly correlated with (E)-2-hexenal content, from which the ω-3 fatty acid desaturase gene IntFAD7 was prioritized. Heterologous expression of IntFAD7 in tobacco significantly elevated α-linolenic acid levels and enhanced (E)-2-hexenal content. Furthermore, promoter analysis, transcriptional activation assays, and yeast one-hybrid assays suggested that IntMYB306 and ABA-related signaling may participate in the upstream regulation of IntFAD7, supporting a putative IntMYB306-ABA-IntFAD7 regulatory model associated with (E)-2-hexenal accumulation. These findings provide both a green extraction strategy for (E)-2-hexenal-rich essential oil from I. noli-tangere leaves and a molecular framework for improving plant-derived antifungal volatile production.PMID:42697660 | DOI:10.1016/j.pestbp.2026.107291