title: Priming of jasmonate-mediated antiherbivore defense responses in rice by silicon.
abstract: Although the function of silicon (Si) in plant physiology has long been debated, its beneficial effects on plant resistance against abiotic and biotic stresses, including insect herbivory, have been well documented. In addition, the jasmonate (JA) signaling pathway plays a crucial role in mediating antiherbivore defense responses in plants. However, potential interactions between JA and Si in response to insect attack have not been examined directly. To explore the role JA may play in Si-enhanced resistance, we silenced the expression of allene oxide synthase (OsAOS; active in JA biosynthesis) and CORONATINE INSENSITIVE1 (OsCOI1; active in JA perception) genes in transgenic rice plants via RNAi and examined resulting changes in Si accumulation and defense responses against caterpillar Cnaphalocrocis medinalis (rice leaffolder, LF) infestation. Si pretreatment increased rice resistance against LF larvae in wild-type plants but not in OsAOS and OsCOI1 RNAi lines. Upon LF attack, wild-type plants subjected to Si pretreatment exhibited enhanced defense responses relative to untreated controls, including higher levels of JA accumulation; increased levels of transcripts encoding defense marker genes; and elevated activities of peroxidase, polyphenol oxidase, and trypsin protease inhibitor. Additionally, reduced Si deposition and Si cell expansion were observed in leaves of OsAOS and OsCOI1 RNAi plants in comparison with wild-type plants, and reduced steady-state transcript levels of the Si transporters OsLsi1, OsLsi2, and OsLsi6 were observed in Si-pretreated plants after LF attack. These results suggest a strong interaction between Si and JA in defense against insect herbivores involving priming of JA-mediated defense responses by Si and the promotion of Si accumulation by JA.
authors.affiliation: State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources and Key Laboratory of Tropical Agro-environment, Ministry of Agriculture, South China Agricultural University, Wushan, Guangzhou 510642, People's Republic of China.
authors.forename: Mao
authors.initials: M
authors.lastname: Ye
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Song
authors.forename: Jun
authors.initials: J
authors.lastname: Long
authors.forename: Ruilong
authors.initials: R
authors.lastname: Wang
authors.forename: Scott R
authors.initials: SR
authors.lastname: Baerson
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Pan
authors.forename: Keyan
authors.initials: K
authors.lastname: Zhu-Salzman
authors.forename: Jiefen
authors.initials: J
authors.lastname: Xie
authors.forename: Kunzheng
authors.initials: K
authors.lastname: Cai
authors.forename: Shiming
authors.initials: S
authors.lastname: Luo
authors.forename: Rensen
authors.initials: R
authors.lastname: Zeng
mesh_terms: D000818:Animals; D004156:Catechol Oxidase / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D020868:Gene Silencing; D006360:Heat-Shock Proteins / Q000235:genetics; D060434:Herbivory / Q000502:physiology; D019746:Intramolecular Oxidoreductases / Q000235:genetics; D009036:Moths / Q000502:physiology*; D012275:Oryza / Q000378:metabolism* / Q000502:physiology; D054883:Oxylipins / Q000378:metabolism*; D009195:Peroxidase / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D012825:Silicon / Q000032:analysis / Q000378:metabolism*; D012987:Soil / Q000032:analysis*; D014361:Trypsin Inhibitors / Q000378:metabolism
chemical_list: D003517:Cyclopentanes; D006360:Heat-Shock Proteins; D054883:Oxylipins; D012987:Soil; D014361:Trypsin Inhibitors; C011006:jasmonic acid; D004156:Catechol Oxidase; D009195:Peroxidase; D019746:Intramolecular Oxidoreductases; C021377:hydroperoxide isomerase; D012825:Silicon
keywords: Oryza sativa; induced defense; jasmonic acid; mitogen-activated protein kinase