Determination Suppressive Effect of Satellite 369 on Accumulation of Cucumber Mosaic Virus by Real-Time Reverse Transcript-Polymerase Chain Reaction

Sat369 is a 369-nt cucumber mosaic virus satellite RNA (CMV-sartRNA), it can attenuate the symptom induced by CMV. To study the mechanism by which the symptom was altered, real-time reverse transcript-polymerase chain reaction (RT-PCR) was applied to examine the accumulation kinetics of viral genes at the absence or presence of sat369. The results showed that sat369 depressed the accumulation of all viral genes but with different degrees, its effects on 2b, 1a and 2a genes were more remarkable than that of MP and CP genes, and the suppression effects were more considerable at early than later stage of infection. Besides this, the time points of maximum levels of CMV genes were delayed by 7 days in the presence of sat369. These results were confirmed by northern blotting, and indicated that the attenuated symptom in the presence of sat369 might be the results of low accumulation levels of CMV genes, especially at early time post-inoculation, 1a, 2a and 2b genes were all involved in this complex interaction.