Chalcone Synthase-Encoding <i>AeCHS</i> is Involved in Normal Petal Coloration in <i>Actinidia eriantha</i>

• Main Authors: Yukuo Li, Wen Cui, Xiujuan Qi, Chengkui Qiao, Miaomiao Lin, Yunpeng Zhong, Chungen Hu, Jinbao Fang
• Format: Article
• Language: English
• Published: MDPI AG 2019-11-01
• Series: Genes
• Subjects: anthocyanin; infiltration grafting; structural gene; petal coloration; actinidia eriantha
• Online Access: https://www.mdpi.com/2073-4425/10/12/949

Studies on anthocyanin biosynthesis have been mainly concentrated on the fruit, whereas few have focused the mechanism of flower coloration in kiwifruit. Here, we report that the structural gene, AeCHS, is involved in anthocyanin accumulation and indispensable for normal petal coloration in Actinidia eriantha. Petals from three different species including Actinidia eriantha (red petals), Actinidia hemsleyana (light pink petals) and Actinidia arguta (white petals) were selected for anthocyanin determination and gene expression analysis. The anthocyanin components in <i>A. eriantha </i>were significantly higher than in A. hemsleyana or A. arguta. Consistently, gene expression profiles suggested that AeCHS expression in <i>A. eriantha </i>was higher than in A. hemsleyana or A. arguta. Cluster analysis showed that AeCHS was clustered into a single group and distinctly separated from other genes, indicating the expression pattern of AeCHS gene was different from any other. Additionally, correlation analysis revealed AeCHS expression significantly correlated with anthocyanin content. The complete coding sequence of <i>AeCHS</i> was cloned from petals of <i>A. eriantha </i>&#8216;Zaoxu&#8217;, showing the length of <i>AeCHS </i>was 1170 bp encoding a protein of 389 amino acids. <i>AeCHS</i> was located in the cytoplasm, indicating it<i> </i>is indeed a structural gene involved in anthocyanin biosynthesis. <i>AeCHS </i>silencing<i> </i>performed by infiltration grafting-mediated virus-induced gene silencing (VIGS) reduced petal anthocyanin content and bleached red petals in <i>A. eriantha</i>. Our results confirm a crucial role of <i>AeCHS</i> in anthocyanin biosynthesis and accumulation in <i>A. eriantha </i>petals; furthermore, they offer important basic information and constitute a reference point for further research.