Senda Mineo, Masuta Chikara, Ohnishi Shizen, Goto Kazunori, Kasai Atsushi, Sano Teruo, Hong Jin-Sung, MacFarlane Stuart
Gene Research Center, Hirosaki University, Hirosaki, 036-8561, Japan.
Plant Cell. 2004 Apr;16(4):807-18. doi: 10.1105/tpc.019885. Epub 2004 Mar 22.
Most commercial Glycine max (soybean) varieties have yellow seeds because of loss of pigmentation in the seed coat. It has been suggested that inhibition of seed coat pigmentation in yellow G. max may be controlled by homology-dependent silencing of chalcone synthase (CHS) genes. Our analysis of CHS mRNA and short-interfering RNAs provide clear evidence that the inhibition of seed coat pigmentation in yellow G. max results from posttranscriptional rather than transcriptional silencing of the CHS genes. Furthermore, we show that mottling symptoms present on the seed coat of G. max plants infected with some viruses can be caused by suppression of CHS posttranscriptional gene silencing (PTGS) by a viral silencing suppressor protein. These results demonstrate that naturally occurring PTGS plays a key role in expression of a distinctive phenotype in plants and present a simple clear example of the elucidation of the molecular mechanism for viral symptom induction.
大多数商业种植的大豆品种种子呈黄色，这是因为种皮色素沉着缺失。有人提出，黄色大豆种皮色素沉着的抑制可能受查尔酮合酶（CHS）基因的同源依赖性沉默控制。我们对CHS信使核糖核酸（mRNA）和小干扰RNA的分析提供了明确证据，表明黄色大豆种皮色素沉着的抑制是由CHS基因的转录后沉默而非转录沉默导致的。此外，我们发现感染某些病毒的大豆植株种皮上出现的斑驳症状，可能是由病毒沉默抑制蛋白抑制CHS转录后基因沉默（PTGS）引起的。这些结果表明，天然存在的PTGS在植物独特表型的表达中起关键作用，并为阐明病毒症状诱导的分子机制提供了一个简单明了的例子。
