Biochemistry Department, Stellenbosch University, Private Bag X1, Matieland, South Africa.
University of the Free State, Bloemfontein, South Africa.
Ann Bot. 2019 Aug 2;124(1):121-130. doi: 10.1093/aob/mcz046.
Floral colour in angiosperms can be controlled by variations in the expression of the genes of the anthocyanin pathway. Floral colour shifts influence pollinator specificity. Multiple shifts in floral colour occurred in the diversification of the genus Erica (Ericaceae), from plesiomorphic pink to, for example, red or white flowers. Variation in anthocyanin gene expression and its effects on floral colour in the red-, pink- and white-flowered Erica plukenetii species complex was investigated.
Next generation sequencing, reverse transcriptase PCR and real-time reverse transcriptase quantitative PCR were used to quantify anthocyanin gene expression.
Non-homologous mutations causing loss of expression of single genes were found, indicating that the cause was likely to be mutations in transcription factor binding sites upstream of the 5'-untranslated region of the genes, and this was confirmed by sequencing.
Independent evolution and subsequent loss of expression of anthocyanin genes may have influenced diversification in the E. plukenetii species complex. The approach developed here should find more general application in studies on the role of floral colour shifts in diversification.
被子植物的花色可通过花色形成途径中基因表达的变化来控制。花色的变化会影响传粉者的专一性。在帚石楠属（Ericaceae）的多样化过程中，花色发生了多次变化，从原始的粉色变为例如红色或白色的花朵。本研究调查了花色为红色、粉色和白色的帚石楠属 plukenetii 种复合体中花色形成途径中花色形成基因表达的变化及其对花色的影响。
采用下一代测序、反转录 PCR 和实时反转录定量 PCR 技术来定量花色形成基因的表达。
发现了导致单个基因表达缺失的非同义突变，表明原因可能是转录因子结合位点的突变，导致基因 5'-非翻译区上游序列发生改变，通过测序得到了证实。
花色形成基因的独立进化和随后的表达缺失可能影响了帚石楠属 plukenetii 种复合体的多样化。本研究中采用的方法在花色变化在多样化中的作用研究中应该有更广泛的应用。
