Teng Dong, Liu Danfeng, Khashaveh Adel, Lv Beibei, Sun Peiyao, Geng Ting, Cui Hongzhi, Wang Yi, Zhang Yongjun
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Centre for Invasion Biology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming 650504, China.
J Adv Res. 2025 May;71:29-41. doi: 10.1016/j.jare.2024.05.022. Epub 2024 May 26.
As an important herbivore-induced plant volatile, (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) is known for its defensive role against multiple insect pests, including attracting natural enemies. A terpene synthase (GhTPS14) and two cytochrome P450 (GhCYP82L1, GhCYP82L2) enzymes are involved in the de novo synthesis of DMNT in cotton. We conducted a study to test the potential of manipulating DMNT-synthesizing enzymes to enhance plant resistance to insects.
To manipulate DMNT emissions in cotton and generate cotton lines with increased resistance to mirid bug Apolygus lucorum.
Biosynthesis and emission of DMNT by cotton plants were altered using CRISPR/Cas9 and overexpression approaches. Dynamic headspace sampling and GC-MS analysis were used to collect, identify and quantify volatiles. The attractiveness and suitability of cotton lines against mirid bug and its parasitoid Peristenus spretus were evaluated through various assays.
No DMNT emission was detected in knockout CAS-L1L2 line, where both GhCYP82L1 and GhCYP82L2 were knocked out. In contrast, gene-overexpressed lines released higher amounts of DMNT when infested by A. lucorum. At the flowering stage, L114 (co-overexpressing GhCYP82L1 and GhTPS14) emitted 10-15-fold higher amounts than controls. DMNT emission in overexpressed transgenic lines could be triggered by methyl jasmonate (MeJA) treatment. Apolygus lucorum and its parasitoid were far less attracted to the double edited CAS-L1L2 plants, however, co-overexpressed line L114 significantly attracted bugs and female wasps. A high dose of DMNT, comparable to the emission of L114, significantly inhibited the growth of A. lucorum, and further resulted in higher mortalities.
Turning down DMNT emission attenuated the behavioral preferences of A. lucorum to cotton. Genetically modified cotton plants with elevated DMNT emission not only recruited parasitoids to enhance indirect defense, but also formed an ecological trap to kill the bugs. Therefore, manipulation of DMNT biosynthesis and emission in plants presents a promising strategy for controlling mirid bugs.
作为一种重要的草食动物诱导型植物挥发物，（3E）-4,8-二甲基-1,3,7-壬三烯（DMNT）以其对多种害虫的防御作用而闻名，包括吸引天敌。一种萜烯合酶（GhTPS14）和两种细胞色素P450（GhCYP82L1、GhCYP82L2）酶参与棉花中DMNT的从头合成。我们开展了一项研究，以测试操纵DMNT合成酶来增强植物对昆虫抗性的潜力。
操纵棉花中DMNT的排放，并培育出对盲蝽蟓绿盲蝽抗性增强的棉花品系。
采用CRISPR/Cas9和过表达方法改变棉花植株中DMNT的生物合成和排放。采用动态顶空采样和气相色谱-质谱联用分析来收集、鉴定和定量挥发物。通过各种试验评估棉花品系对绿盲蝽及其寄生蜂广赤眼蜂的吸引力和适宜性。
在同时敲除GhCYP82L1和GhCYP82L2的基因敲除品系CAS-L1L2中未检测到DMNT排放。相反，基因过表达品系在受到绿盲蝽侵染时释放出更多的DMNT。在开花期，L114（同时过表达GhCYP82L1和GhTPS14）的排放量比对照高10至15倍。过表达转基因品系中的DMNT排放可由茉莉酸甲酯（MeJA）处理触发。绿盲蝽及其寄生蜂对双编辑的CAS-L1L2植株的吸引力要小得多，然而，同时过表达的品系L114对绿盲蝽和雌蜂有显著的吸引力。与L114的排放量相当的高剂量DMNT显著抑制了绿盲蝽的生长，并进一步导致更高的死亡率。
降低DMNT排放减弱了绿盲蝽对棉花的行为偏好。DMNT排放增加的转基因棉花植株不仅吸引寄生蜂以增强间接防御，还形成了一个生态陷阱来杀死绿盲蝽。因此，操纵植物中DMNT的生物合成和排放是控制绿盲蝽的一种有前景的策略。
