AUTHOR=Cui Zhiyi , Yang Zengjiang , Xu Daping TITLE=Synergistic Roles of Biphasic Ethylene and Hydrogen Peroxide in Wound-Induced Vessel Occlusions and Essential Oil Accumulation in Dalbergia odorifera JOURNAL=Frontiers in Plant Science VOLUME=10 YEAR=2019 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00250 DOI=10.3389/fpls.2019.00250 ISSN=1664-462X ABSTRACT=

The heartwood of Dalbergia odorifera (D. odorifera), named “Jiang Xiang” in traditional Chinese medicine, is highly valuable. Mechanical wounding induced the production of “Jiang Xiang” in D. odorifera. Ethylene and hydrogen peroxide (H₂O₂) are proposed to play vital roles in wound signaling. However, little is known about the role of ethylene or H₂O₂ in the wound-induced formation of vessel occlusions and biosynthesis of “Jiang Xiang” in D. odorifera. In this study, the pruning of D. odorifera saplings resulted in the synergistic biosynthesis of biphasic ethylene and H₂O₂, which was followed by formation of vessel occlusions and “Jiang Xiang” in the pruned stems. In this process, the H₂O₂ production stimulated higher biosynthesis of ethylene. Treatments with aminoethoxyvinylglycine (AVG), an inhibitor for ethylene biosynthesis and ascorbate acid (AsA), a scavenger of H₂O₂, markedly reduced the production of ethylene and H₂O₂, respectively, and the corresponding the percentage of vessels with occlusions (PVO), oil content, and the amount of “Jiang Xiang” formed. These results indicate that ethylene and H₂O₂ might be important wound signals in D. odorifera that induce vessel occlusions and formation of “Jiang Xiang,” and thus ethylene and H₂O₂ might play vital roles in “Jiang Xiang” formation in pruned stems of D. odorifera.