AUTHOR=Xu Qingxuan , Wu Changbing , Xiao Da , Jin Zhenyu , Zhang Changrong , Hatt Séverin , Guo Xiaojun , Wang Su 

TITLE=Ecological function of key volatiles in Vitex negundo infested by Aphis gossypii

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1090559

DOI=10.3389/fpls.2022.1090559

ISSN=1664-462X

ABSTRACT=<p>Herbivore induced plant volatiles (HIPVs) are key components of plant-herbivorous-natural enemies communications. Indeed, plants respond to herbivores feeding by releasing HIPVs to attract natural enemies. The present study analyses the effect of HIPVs of <italic>Vitex negundo</italic> (Lamiaceae), an indigenous plant species in northern China, on the predatory ladybug species <italic>Harmonia axyridis.</italic> Y-tube olfactometer bioassay showed that <italic>H. axyridis</italic> adults were significantly attracted by <italic>V. negundo</italic> infested by the aphid <italic>Aphis gossypii.</italic> We analyzed and compared volatile profiles between healthy and <italic>A. gossypii</italic> infested <italic>V. negundo</italic>, screened out the candidate active HIPVs mediated by <italic>A. gossypii</italic> which could attract <italic>H. axyridis</italic>, and tested the olfactory behavior of the candidate active compounds on <italic>H. axyridis</italic>. The gas chromatography-mass spectrometry analysis showed that five volatile compounds were significantly up-regulated after <italic>V. negundo</italic> infestation by <italic>A. gossypii</italic>, and five substances were significantly down-regulated in the terpenoid biosynthesis pathway. The olfactory behavior response showed that <italic>H. axyridis</italic> has significant preference for sclareol, eucalyptol, nonanal and α-terpineol, indicating that this chemical compounds are the important volatiles released by <italic>V. negundo</italic> to attract <italic>H. axyridis</italic>. This study preliminarily clarified that <italic>V. negundo</italic> release HIPVs to attract natural enemies when infected by herbivorous insects. The description of the volatile emission profile enriches the theoretical system of insect-induced volatile-mediated plant defense function of woody plants. Applications in crop protection would lie in designing original strategies to naturally control aphids in orchards.</p>