Abstract
The Wx gene encodes granule-bound starch synthase and is specifically expressed at pollen and endosperm. We constructed two RNAi vectors, pWRI-A and pWRI-B, which transcribe the sense and antisense Wx 5'UTR RNA with intron loop. We analyzed rice transgenic plants carrying these RNAi vectors and investigated both tissue-specific RNAi and the quantitative regulation of suppression efficiency. As a result, the 140bp of sense and antisense 5'UTR dsRNA from both constructs can be a trigger of RNAi and lead to silencing of Wx gene in the endosperm. Furthermore, the transgenic rice carrying pWRI-B which carry the substitution mutation at 5' splice site of the intron leads reduction of silencing effects on quantitative regulation of RNAi. However, in pollen, no severe suppression of Wx gene was observed.
In this report, further investigation of the effects of intron- or the foreign sequence-spacer on RNAi by introduction of various RNAi vectors are discussed.
