| Title: | Herbivore-induced callose deposition on the sieve plates of rice: an important mechanism for host resistance |
| Author(s): | Hao P; Liu C; Wang Y; Chen R; Tang M; Du B; Zhu L; He G; |
| Address: | "Key Laboratory of Ministry of Education for Plant Development Biology, College of Life Sciences, Wuhan University, Wuhan 430072, People's Republic of China" |
| ISSN/ISBN: | 0032-0889 (Print) 1532-2548 (Electronic) 0032-0889 (Linking) |
| Abstract: | "The brown planthopper (Nilaparvata lugens Stal; BPH) is a specialist herbivore on rice (Oryza sativa) that ingests phloem sap from the plant through its stylet mouthparts. Electronic penetration graphs revealed that BPH insects spent more time wandering over plants carrying the resistance genes Bph14 and Bph15, but less time ingesting phloem than they did on susceptible plants. They also showed that their feeding was frequently interrupted. Tests with [(14)C]sucrose showed that insects ingested much less phloem sap from the resistant than the susceptible plants. BPH feeding up-regulated callose synthase genes and induced callose deposition in the sieve tubes at the point where the stylet was inserted. The compact callose remained intact in the resistant plants, but genes encoding beta-1,3-glucanases were activated, causing unplugging of the sieve tube occlusions in susceptible plants. Continuing ingestion led to a remarkable reduction in the susceptible plants' sucrose content and activation of the RAmy3D gene, leading to starch hydrolysis and ultimately carbohydrate deprivation in the plants. Our results demonstrate that BPH feeding induces the deposition of callose on sieve plates in rice and that this is an important defense mechanism that prevents insects from ingesting phloem sap. In response, however, the BPH can unplug sieve tube occlusions by activating beta-1,3-glucanase genes in rice plants" |
| Keywords: | Animals Base Sequence DNA Primers Feeding Behavior Glucosyltransferases/metabolism Insecta/*physiology Oryza/enzymology/*metabolism/parasitology/physiology Phloem Reverse Transcriptase Polymerase Chain Reaction; |
| Notes: | "MedlineHao, Peiying Liu, Caixiang Wang, Yuanyuan Chen, Rongzhi Tang, Ming Du, Bo Zhu, Lili He, Guangcun eng Research Support, Non-U.S. Gov't 2008/02/05 Plant Physiol. 2008 Apr; 146(4):1810-20. doi: 10.1104/pp.107.111484. Epub 2008 Feb 1" |
