The dissemination of insect-borne plant pathogens relies on their ability to influence vector behavior.Certain bacteria-infected plants exhibit increased attractiveness to vectors;however,the underlying mech-anisms re...The dissemination of insect-borne plant pathogens relies on their ability to influence vector behavior.Certain bacteria-infected plants exhibit increased attractiveness to vectors;however,the underlying mech-anisms remain poorly characterized.Huanglongbing(HLB),a devastating citrus disease,is primarily caused by the bacterium"Candidatus Liberibacter asiaticus"(CLas)and transmitted by psyllid vectors.In this study,we demonstrate that the effector protein SDE5,secreted by CLas,suppresses the biosyn-thesis of volatile terpenoids in host citrus plants,thereby enhancing psyllid attraction.Biochemically,SDE5 functions as an inhibitor of bacterial C-type lysozyme,facilitating both CLas infection and psyllid vec-tor attraction.Two plant U-box(PUB)E3 ligases,PUB10 and PUB21,are recruited by SDE5 to promote ubiq-uitination and proteasomal degradation of MYC2,a key transcription factor in jasmonate signaling and terpene-based anti-herbivore defenses.Furthermore,SDE5 interferes with MYC2 dimerization,diminishing its ability to activate terpene biosynthesis genes.This dual suppression markedly reduces volatile terpe-noid emissions in SDE5-transgenic citrus lines,resulting in increased psyllid attraction and enhanced psyl-lid fitness.Conversely,the anti-proteolysis peptide 3-14(APP 3-14),which stabilizes the MYC2 protein and inhibits the HLB pathogen,enhances volatile terpenoid emission and repels psyllids.These findings pro-vide a novel strategy for disrupting mutualistic interactions between plant bacterial pathogens and insect vectors by modulation of olfactory defense.展开更多
研究了薇甘菊MikaniamicranthaH B K 的乙醇、丙酮提取物对菜青虫Pierisrapae和小菜蛾Plutellaxylostella幼虫的生物活性,结果表明,提取物对菜青虫和小菜蛾幼虫具有较强的毒杀和拒食作用。质量浓度为500mg·L-1的乙醇提取物对1～2...研究了薇甘菊MikaniamicranthaH B K 的乙醇、丙酮提取物对菜青虫Pierisrapae和小菜蛾Plutellaxylostella幼虫的生物活性,结果表明,提取物对菜青虫和小菜蛾幼虫具有较强的毒杀和拒食作用。质量浓度为500mg·L-1的乙醇提取物对1～2龄的菜青虫的毒杀作用达到80%,LC50=293 4mg·L-1对2～3龄小菜蛾幼虫的毒杀作用达到70%以上,LC50=343 5mg·L-1。相同质量浓度的丙酮提取物对2种幼虫的毒杀作用略低于乙醇提取物。质量浓度为125mg·L-1的乙醇、丙酮提取物对2种幼虫均具有拒食作用,前者拒食率分别为97 4%和70 4%,后者提取物的拒食率分别为96 5%和98 3%。薇甘菊(干样 培养基)0 02g mL的甲醇、丙酮提取物对辣椒疫霉Phytophthoracapsili、玉米大斑病菌Exserohilumturcicum菌丝的抑制率均为100%。展开更多
基金supported by the China National Key Research and Development Program(2023YFC2606800,2021YFD1400800,and 2024YFC3406000)the National Natural Science Foundation of China(32125032)+2 种基金the Inner Mongolia Science and Technology Program(2023KJHZ0018)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0810000 and XDA0450000)Project of the State Key Laboratory of Discovery and Utilization of Functional Components in Traditional Chinese Medicine.
文摘The dissemination of insect-borne plant pathogens relies on their ability to influence vector behavior.Certain bacteria-infected plants exhibit increased attractiveness to vectors;however,the underlying mech-anisms remain poorly characterized.Huanglongbing(HLB),a devastating citrus disease,is primarily caused by the bacterium"Candidatus Liberibacter asiaticus"(CLas)and transmitted by psyllid vectors.In this study,we demonstrate that the effector protein SDE5,secreted by CLas,suppresses the biosyn-thesis of volatile terpenoids in host citrus plants,thereby enhancing psyllid attraction.Biochemically,SDE5 functions as an inhibitor of bacterial C-type lysozyme,facilitating both CLas infection and psyllid vec-tor attraction.Two plant U-box(PUB)E3 ligases,PUB10 and PUB21,are recruited by SDE5 to promote ubiq-uitination and proteasomal degradation of MYC2,a key transcription factor in jasmonate signaling and terpene-based anti-herbivore defenses.Furthermore,SDE5 interferes with MYC2 dimerization,diminishing its ability to activate terpene biosynthesis genes.This dual suppression markedly reduces volatile terpe-noid emissions in SDE5-transgenic citrus lines,resulting in increased psyllid attraction and enhanced psyl-lid fitness.Conversely,the anti-proteolysis peptide 3-14(APP 3-14),which stabilizes the MYC2 protein and inhibits the HLB pathogen,enhances volatile terpenoid emission and repels psyllids.These findings pro-vide a novel strategy for disrupting mutualistic interactions between plant bacterial pathogens and insect vectors by modulation of olfactory defense.
