Jiangsu Key Laboratory for Food and Safety (State Key Laboratory Cultivation Base of Ministry of Science and Technology), Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China.
CAS Key Laboratory of Insect Developmental and Evolutionary Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
Plant Cell Environ. 2024 Jul;47(7):2426-2442. doi: 10.1111/pce.14889. Epub 2024 Mar 18.
Damage caused by the rice striped stem borer (SSB), Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is much more severe on indica/xian rice than on japonica/geng rice (Oryza sativa) which matches pest outbreak data in cropping regions of China. The mechanistic basis of this difference among rice subspecies remains unclear. Using transcriptomic, metabolomic and genetic analyses in combination with insect bioassay experiments, we showed that japonica and indica rice utilise different defence responses to repel SSB, and that SSB exploited plant nutrition deficiencies in different ways in the subspecies. The more resistant japonica rice induced patterns of accumulation of methyl jasmonate (MeJA-part of a defensive pathway) and vitamin B (VB-a nutrition pathway) distinct from indica cultivars. Using gene-edited rice plants and SSB bioassays, we found that MeJA and VB jointly affected the performance of SSB by disrupting juvenile hormone levels. In addition, genetic variants of key biosynthesis genes in the MeJA and VB pathways (OsJMT and OsTH1, respectively) differed between japonica and indica rice and contributed to performance differences; in indica rice, SSB avoided the MeJA defence pathway and hijacked the VB nutrition-related pathway to promote development. The findings highlight important genetic and mechanistic differences between rice subspecies affecting SSB damage which could be exploited in plant breeding for resistance.
由二化螟（Chilo suppressalis（Walker））（鳞翅目：螟蛾科）造成的损害在籼稻上比在粳稻上更为严重（Oryza sativa），这与中国种植区的虫害爆发数据相吻合。亚种间这种差异的机制基础仍不清楚。本研究采用转录组学、代谢组学和遗传分析，并结合昆虫生物测定实验，表明粳稻和籼稻利用不同的防御反应来抵御二化螟，而二化螟在亚种间以不同的方式利用植物营养缺乏。抗性更强的粳稻诱导了茉莉酸甲酯（MeJA-防御途径的一部分）和维生素 B（VB-营养途径）的积累模式，与籼稻品种明显不同。通过基因编辑水稻植物和二化螟生物测定，我们发现 MeJA 和 VB 通过破坏保幼激素水平共同影响二化螟的表现。此外，MeJA 和 VB 途径中关键生物合成基因（分别为 OsJMT 和 OsTH1）的遗传变异在粳稻和籼稻之间存在差异，导致表现差异；在籼稻中，二化螟避开了 MeJA 防御途径，劫持了 VB 与营养相关的途径来促进发育。这些发现强调了影响二化螟损害的水稻亚种之间的重要遗传和机制差异，这可以在植物抗虫性育种中加以利用。
