The Role of Salicylic Acid in Systemic Acquired Resistance Signaling Pathways
FAN Zhi-Jin 1,2,LIU Xiu-Feng1,LIU Feng-Li1,ZHENG Bing-Cai1,LI Shu-Zheng1 (1 Institute of Elemento Organic Chemistry,Nankai University,State Key Laboratory of Elemento Organic Chemistry,Nankai University,Tianjin 300071,China; 2 Key Laboratory of Pesticide Chemistry & Application Technology of Ministry of Agriculture,Beijing 100094,China)
Salicylic acid (SA) is an important endogenous compound in plant signaling pathways. Exogenous SA can induce expression of plant defense genes and lead to a degree of protection against plant pathogens. Increases in endogenous SA levels correlates with expression of defense genes and development of pathogen resistance,indicating that SA is required in the expession of systemic acquired resistance (SAR) but is not the only factor. SAR expression results from joint action of SA and other compounds. SAR induces the plant to generate a signal at the site of infection,and this signal can then be translocated systemically to the entire plant by a signal transmitting compound. SA may be serving as the signal transmitter,although the chemical nature and molecular mechanism of the signal transmitter still lacks experimental evidence.