These authors contributed equally to the study.
Physiological and cytological mechanisms of silicon-induced resistance in rice against blast disease
Version of Record online: 30 MAY 2008
© Physiologia Plantarum 2008
Volume 134, Issue 2, pages 324–333, October 2008
How to Cite
Cai, K., Gao, D., Luo, S., Zeng, R., Yang, J. and Zhu, X. (2008), Physiological and cytological mechanisms of silicon-induced resistance in rice against blast disease. Physiologia Plantarum, 134: 324–333. doi: 10.1111/j.1399-3054.2008.01140.x
- Issue online: 15 SEP 2008
- Version of Record online: 30 MAY 2008
- Received 26 January 2008; revised 23 April 2008
Rice (Oryza sativa L.) blast disease caused by Magnaporthe grisea is one of the most destructive diseases in the rice-growing areas of the world. Silicon is an important nutritional element especially for rice. Two near-isogenic lines of rice with different resistance to blast disease, i.e. CO39 (susceptible) and C101LAC (Pi-1) (resistant), were selected to determine the effects of Si amendment on the severity and incidence of rice blast disease. The physiological and cytological mechanisms involved in the induced disease resistance by silicon were investigated. Exogenous Si application at a concentration of 2 mM reduced the disease index by 45% for CO39 and 56% for C101LAC (Pi-1). Si application alone did not change lignin content and the activities of defense-related enzymes including peroxidase (POD), polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) in rice leaves of both isogenic lines. However, after inoculation with M. grisea, Si-treated rice plants significantly increased the activities of POD, PPO and PAL in leaves of both isogenic lines. Si and lignin content were also significantly increased in Si-treated inoculated seedlings. Environmental scanning electron microscope observations revealed that Si amendment resulted in higher Si deposit on dumbbell bodies in the rice leaves and silicon papilla accumulation on the guard cell of stoma. These results suggest that silicon-induced defense response and cell silicification of rice leaves altogether contribute to the silicon-induced rice resistance to blast disease.