文献类型： 外文期刊

作者： Huang, Xinzheng ¹ ; Zhang, Hang ² ; Li, Huali ¹ ; Wang, Mengting ¹ ; Guo, Xinyue ¹ ; Liu, Enliang ⁵ ; Han, Xiaoqiang ⁴ ; Zhen, Congai ¹ ; Li, Aili ² ; Shi, Wangpeng ¹ ; Zhang, Yongjun ² ;

作者机构： 1.China Agr Univ, Coll Plant Protect, Dept Entomol, MOA Key Lab Pest Monitoring & Green Management, Beijing, Peoples R China

2.Chinese Acad Agr Sci, Inst Plant Protect, State Key Lab Biol Plant Dis & Insect Pests, Beijing, Peoples R China

3.Xinjiang Prod & Construct Corps, Gen Stn Agr Technol Extens, Urumqi, Peoples R China

4.Shihezi Univ, Coll Agr, Key Lab Oasis Agr Pest Management & Plant Protect, Shihezi, Xinjiang Uygur, Peoples R China

5.XinJiang Acad Agr Sci, Inst Grain Crops, Urumqi, Peoples R China

关键词： wild pear; Spodoptera litura; plant-insect interactions; (E)-beta-ocimene biosynthesis; plant defense

期刊名称：FRONTIERS IN PLANT SCIENCE （ 2021影响因子：6.627； 五年影响因子：7.255 ）

ISSN： 1664-462X

年卷期： 2022 年 13 卷

页码：

收录情况： SCI

摘要： (E)-beta-ocimene, a ubiquitous monoterpene volatile in plants, is emitted from flowers to attract pollinators and/or from vegetative tissues as part of inducible defenses mediated by complex signaling networks when plants are attacked by insect herbivores. Wild pear species Pyrus betuleafolia used worldwide as rootstock generally displays valuable pest-resistant traits and is a promising genetic resource for pear breeding. In the current study, transcriptional changes in this wild pear species infested with a polyphagous herbivore Spodoptera litura and the underlying molecular mechanisms were fully investigated. A total of 3,118 differentially expressed genes (DEGs) were identified in damaged pear leaf samples. Spodoptera litura larvae infestation activated complex phytohormonal signaling networks in which jasmonic acid, ethylene, brassinosteroids, cytokinin, gibberellic acid and auxin pathways were induced, whereas salicylic acid and abscisic acid pathways were suppressed. All DEGs associated with growth-related photosynthesis were significantly downregulated, whereas most DEGs involved in defense-related early signaling events, transcription factors, green leaf volatiles and volatile terpenes were significantly upregulated. The PbeOCS (GWHGAAYT028729), a putative (E)-beta-ocimene synthase gene, was newly identified in P. betuleafolia transcriptome. The upregulation of PbeOCS in S. litura-infested pear leaves supports a potential role for PbeOCS in herbivore-induced plant defenses. In enzyme-catalyzed reaction, recombinant PbeOCS utilized only geranyl pyrophosphate but not neryl diphosphate, farnesyl pyrophosphate or geranylgeranyl diphosphate as a substrate, producing (E)-beta-ocimene as the major product and a trace amount of (Z)-beta-ocimene. Moreover, as a catalytic product of PbeOCS, (E)-beta-ocimene showed repellent effects on larvae of S. litura in dual-choice bioassays. What is more, (E)-beta-ocimene increased mortalities of larvae in no-choice bioassays. These findings provide an overview of transcriptomic changes in wild pears in response to chewing herbivores and insights into (E)-beta-ocimene biosynthesis in pear plants, which will help elucidate the molecular mechanisms underlying pear-insect interactions.