Pre-harvest sprouting (PHS) reduces yields and grain quality, resulting in seriously economic losses in wheat. It has been showed that PHS is significantly correlated to seed dormancy levels. <em>FUSCA3</em&g...Pre-harvest sprouting (PHS) reduces yields and grain quality, resulting in seriously economic losses in wheat. It has been showed that PHS is significantly correlated to seed dormancy levels. <em>FUSCA3</em> (<em>FUS3</em>) gene is considered to be the key regulator of seed dormancy. However, little information is available about the function of <em>FUS3</em> gene (<em>TaFUS3</em>) in wheat. In this study, three homologous genes were identified in wheat grain, and their functions were investigated by gene silencing. Three full-length DNA (3477, 3534 and 3501 bp) and cDNA (1015, 1012 and 1015 bp) sequences encoding a B3 transcription factor, designated <em>TaFUS3-3A</em>, <em>TaFUS3-3B</em> and <em>TaFUS3-3D</em>, were first isolated from common wheat. The transcription of three <em>TaFUS3</em> genes in seed development and germination process was detected.<em> TaFUS3-3B</em> and<em> TaFUS3-3D</em> had similar expression profiles, and high levels of gene transcripts were detected in seeds at 25 DAP (days after pollination) and after 24 h of imbibition. However, the transcription of <em>TaFUS3-3A </em>was not detected. Silencing of <em>TaFUS3</em> in common wheat spikes resulted in increased seed germination and PHS. Compared with wild-type, the <em>TaFUS3</em>-silenced plants showed increased expression of genes related to GA biosynthesis and ABA metabolism, and decreased expression of genes associated with ABA biosynthesis. Moreover, silencing of <em>TaFUS3</em> in wheat plants led to a decrease in embryo sensitivity to ABA and changed the expression of genes involved in ABA signal transduction. The results of gene silencing indicated that<em> TaFUS3</em> plays a positive role in wheat seed dormancy and PHS-resistance, which might be associated with ABA, GA level and signal transduction.展开更多
文摘Pre-harvest sprouting (PHS) reduces yields and grain quality, resulting in seriously economic losses in wheat. It has been showed that PHS is significantly correlated to seed dormancy levels. <em>FUSCA3</em> (<em>FUS3</em>) gene is considered to be the key regulator of seed dormancy. However, little information is available about the function of <em>FUS3</em> gene (<em>TaFUS3</em>) in wheat. In this study, three homologous genes were identified in wheat grain, and their functions were investigated by gene silencing. Three full-length DNA (3477, 3534 and 3501 bp) and cDNA (1015, 1012 and 1015 bp) sequences encoding a B3 transcription factor, designated <em>TaFUS3-3A</em>, <em>TaFUS3-3B</em> and <em>TaFUS3-3D</em>, were first isolated from common wheat. The transcription of three <em>TaFUS3</em> genes in seed development and germination process was detected.<em> TaFUS3-3B</em> and<em> TaFUS3-3D</em> had similar expression profiles, and high levels of gene transcripts were detected in seeds at 25 DAP (days after pollination) and after 24 h of imbibition. However, the transcription of <em>TaFUS3-3A </em>was not detected. Silencing of <em>TaFUS3</em> in common wheat spikes resulted in increased seed germination and PHS. Compared with wild-type, the <em>TaFUS3</em>-silenced plants showed increased expression of genes related to GA biosynthesis and ABA metabolism, and decreased expression of genes associated with ABA biosynthesis. Moreover, silencing of <em>TaFUS3</em> in wheat plants led to a decrease in embryo sensitivity to ABA and changed the expression of genes involved in ABA signal transduction. The results of gene silencing indicated that<em> TaFUS3</em> plays a positive role in wheat seed dormancy and PHS-resistance, which might be associated with ABA, GA level and signal transduction.
