Silencing JA hydroxylases in Nicotiana attenuata enhances jasmonic acid-isoleucine-mediated defenses against Spodoptera litura  

作　　者：Jinxiang Tang Dahai Yang Jianqiang Wu Suiyun Chen Lei Wang 

机构地区：[1]Department of Economic Plants and Biotechnology,Yunnan Key Laboratory for Wild Plant Resources,Kunming Institute of Botany,Chinese Academy of Sciences,Kunming,650201,China [2]Tobacco Breeding and Biotechnology Research Center,Yunnan Academy of Tobacco Agricultural Sciences,Key Laboratory of Tobacco Biotechnological Breeding,National Tobacco Genetic Engineering Research Center,Kunming,650021,China [3]School of Life Science,Yunnan University,Kunming,650091,China

出　　处：《Plant Diversity》2020年第2期111-119,共9页植物多样性（英文版）

基　　金：supported by the Key Project of Applied Basic Research Program of Yunnan(2017FA015);the Young Academic and Technical Leader Raising Foundation of Yunnan Province(no. 2017HB063);the Yunnan Academy of Tobacco Agricultural Sciences(2018530000241002 and 2019530000241003);the Biotechnology Experimental Center at the Kunming Institute of Botany,CAS,for supporting plant cultivation.

摘　　要：Jasmonic acid(JA)plays important roles in plant resistance to insect herbivores.One important derivative of JA is 12-OH-JA,which is produced by two independent pathways:direct hydroxylation of JA by jasmonate-induced oxygenases(JOXs)or hydrolyzation of 12-OH-JA-Ile.Yet the function of 12-OH-JA in plant-herbivore interactions remains largely unknown.In this study,we silenced four JOX homologs independently in the wild tobacco Nicotiana attenuata by virus-induced gene silencing(VIGS),and found that all four JOX homologs are involved in JA hydroxylation.Simultaneously silencing the four JA hydroxylases in VIGS-NaJOXs plants decreased herbivory-induced 12-OH-JA by 33%,but JA and JA-Ile levels increased by 45%and 30%,respectively,compared to those in control plants.Compared to direct hydroxylation from JA,hydrolyzation from 12-OH-JA-Ile is equally important for herbivory-induced 12-OHJA accumulation:in the 12-OH-JA-Ile deficient irJAR4/6 plants,12-OH-JA decreased 34%.Moreover,VIGSNaJOXs plants exhibited enhanced resistance to the generalist herbivore Spodoptera litura.The poor larval performance was strongly correlated with high levels of several JA-Ile-dependent direct defense metabolites in the VIGS-NaJOXs plants.When we simultaneously silenced all four JA hydroxylases in the JAIle-deficient irJAR4/6 background,the enhanced herbivore resistance diminished,demonstrating that enhanced herbivore resistance resulted from elevated JA-Ile levels.Given that silencing these NaJOX-like genes did not detectably alter plant growth but highly increased plant defense levels,we propose that JOX genes are potential targets for genetic improvement of herbivore-resistant crops.

关 键 词：JA metabolism 12-OH-JA SPODOPTERA litura 2-Oxoglutarate oxygenase HERBIVORE defense Nicotiana attenuata 

分 类 号：S432[农业科学—植物病理学]