| Title: | Silencing JA hydroxylases in Nicotiana attenuata enhances jasmonic acid-isoleucine-mediated defenses against Spodoptera litura |
| Author(s): | Tang J; Yang D; Wu J; Chen S; Wang L; |
| Address: | "Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, China. School of Life Science, Yunnan University, Kunming, 650091, China. 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" |
| DOI: | 10.1016/j.pld.2019.11.005 |
| ISSN/ISBN: | 2468-2659 (Electronic) 2096-2703 (Print) 2468-2659 (Linking) |
| Abstract: | "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-OH-JA accumulation: in the 12-OH-JA-Ile deficient irJAR4/6 plants, 12-OH-JA decreased 34%. Moreover, VIGS-NaJOXs 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 JA-Ile-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" |
| Keywords: | 12-oh-ja 2-Oxoglutarate oxygenase Herbivore defense JA metabolism Nicotiana attenuata Spodoptera litura; |
| Notes: | "PubMed-not-MEDLINETang, Jinxiang Yang, Dahai Wu, Jianqiang Chen, Suiyun Wang, Lei eng China 2020/05/07 Plant Divers. 2020 Jan 3; 42(2):111-119. doi: 10.1016/j.pld.2019.11.005. eCollection 2020 Apr" |
