Studies On The Rice Ragged Stunt Virus Effects On Phosphorus Metabolism

Rice ragged stunt virus （RRSV）is one of the most serious rice diseases in recent years.Since itwas discovered, Rice ragged stunt disease caused by RRSV is happened in many countries of theSouthern east Asia, East Asia and Southern Asia. This disease can cause huge losses of rice andthe most serious season could cause100%incidence. RRSV is the typical member of Oryzavirusin Reoviridae. The genome of RRSV consists of10double-stranded RNAs, and they are namedstrand1-strand10respectively. Besides, it encodes eleven proteins and each protein has differentfunction. The most important thing is that the symptoms of rice infected with RRSV is quitesimilar to the symptoms of rice lacking phosphorus. So we think that RRSV must be connectedwith the supersession of phosphorous.This paper firstly discussed and validated the difference of phosphorus content between the riceplants infected with RRSV and healthy rice plants. The findings show that not only in the stem,leaves but also in the root the phosphorus content of rice infected RRSV is lower than healthy rice.This part of experiment is mainly doing in the field. It suggests that RRSV is perhaps related withthe phosphorus metabolism of rice. Then we dig seven key genes in the process of phosphorustransportation such as TRXH, PHR2, PSS1, PHO1, SPX1, SPX4, Os-MiR399and detect differentexpression of each gene in diseased plants and healthy plants respectively using real-time PCR.The results display that the expression of the seven genes in healthy rice is much more than theexpression of those genes in the rice ragged stunt disease plants. It also can indicate thatRRSV might be associated with the lower expression of7key genes influencing onthe rice phosphorus metabolism and this process will reduce the phosphorus absorption of rice.Based on that Os-MiR399, one of the most important gene in the channel of phosphorusmetabolism, is playing a dual role of transmitting and receiving signals in the process of phosphatepathway,4different precursors of MiR399were chosen as the research object to carry on thegenetically modified experiment. Now we have already cultivated several transgenic plants.