Fe₃O₄ nanoparticles elicit athe defense response in Nicotiana benthamiana against TMV by activating salicylate-dependent signaling pathways

【作者】 蔡璘； LIU Changyun； GAO Changdan； FENG Hui； Fan Guangjin； WANG Daibin； RAN Mao； XU Chen； XU Xiaohong； 孙现超；

【Author】 CAI Lin;LIU Changyun;GAO Changdan;FENG Hui;Fan Guangjin;WANG Daibin;RAN Mao;XU Chen;XU Xiaohong;SUN Xianchao;College of Plant Protection,Southwest University;Chongqing Tobacco Science Research Institute;

【机构】 College of Plant Protection,Southwest University； Chongqing Tobacco Science Research Institute；

【摘要】 Control of plant pathogens can be realized by improving plant systemic resistance or direct antimicrobial activity against the pathogen.The nanoparticles were employed as a new strategy to directly kill pathogens（bacteria and fungus） and to act as nanofertilizers to facilitate plant growth.However,the improving the capabilities of the plant defense by nanoparticles against viruses towards plants are poorly understood.Here,we developed nanoparticles as new plant immune inducer against virus in agriculture and systematically investigated the plant resistance to attack by tobacco mosaic virus（TMV） triggered by treating plants with Fe₃ O₄ nanoparticles（Fe₃ O₄ NPs）.Interestingly,the antiviral action of Fe3 O4 NPs is mainly due to the regulation of plant cell signaling pathways by the NPs.Specifically,by foliar spraying,Fe₃ O₄ NPs were able to enter the leaf cells,reaching inside or near chloroplasts and were transported and accumulated throughout the whole plant tissue.The Fe₃ O₄ NPs increased the plant dry weight and fresh weight,activated plant antioxidants,and upregulated SA synthesis and the expression of the SA-responsive PR genes（PR1 and PR2）,which finally enhanced the plant disease-resistance ability against TMV.Meanwhile,the TMV particles were partly aggregated and fractured after pretreatment with the NPs in vitro for 2 h.However,there was no significant difference between the NPs and the control group in the ability of the virus to colonize in the plant at 7 dpi after inoculating the pretreated TMV mixtures onto tobacco leaves.These results suggest that the difference in the two outcomes was attributed to foliar spraying of Fe₃ O₄ NPs before TMV infection,which induced plant resistance.In contrast,TMV inactivation by NPs was insufficient to prevent viral replication and accumulation in the host plant.Altogether,Fe₃ O₄ NPs,are a novel,promising,efficient and candidate resistance inducer for plants,which broadens the avenues for researching and applying NPs in the fight against plant diseases.更多还原

【Abstract】 Control of plant pathogens can be realized by improving plant systemic resistance or direct antimicrobial activity against the pathogen.The nanoparticles were employed as a new strategy to directly kill pathogens（bacteria and fungus） and to act as nanofertilizers to facilitate plant growth.However,the improving the capabilities of the plant defense by nanoparticles against viruses towards plants are poorly understood.Here,we developed nanoparticles as new plant immune inducer against virus in agriculture and systematically investigated the plant resistance to attack by tobacco mosaic virus（TMV） triggered by treating plants with Fe₃ O₄ nanoparticles（Fe₃ O₄ NPs）.Interestingly,the antiviral action of Fe3 O4 NPs is mainly due to the regulation of plant cell signaling pathways by the NPs.Specifically,by foliar spraying,Fe₃ O₄ NPs were able to enter the leaf cells,reaching inside or near chloroplasts and were transported and accumulated throughout the whole plant tissue.The Fe₃ O₄ NPs increased the plant dry weight and fresh weight,activated plant antioxidants,and upregulated SA synthesis and the expression of the SA-responsive PR genes（PR1 and PR2）,which finally enhanced the plant disease-resistance ability against TMV.Meanwhile,the TMV particles were partly aggregated and fractured after pretreatment with the NPs in vitro for 2 h.However,there was no significant difference between the NPs and the control group in the ability of the virus to colonize in the plant at 7 dpi after inoculating the pretreated TMV mixtures onto tobacco leaves.These results suggest that the difference in the two outcomes was attributed to foliar spraying of Fe₃ O₄ NPs before TMV infection,which induced plant resistance.In contrast,TMV inactivation by NPs was insufficient to prevent viral replication and accumulation in the host plant.Altogether,Fe₃ O₄ NPs,are a novel,promising,efficient and candidate resistance inducer for plants,which broadens the avenues for researching and applying NPs in the fight against plant diseases.更多还原