Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, Brisbane, Australia.
Centre for Crop Science, QAAFI, The University of Queensland, Brisbane, Australia.
Mol Genet Genomics. 2023 Nov;298(6):1395-1405. doi: 10.1007/s00438-023-02060-y. Epub 2023 Sep 8.
Recently, a novel purple-pericarp super-sweetcorn line, 'Tim1' (A1A1.sh2sh2) was derived from the purple-pericarp maize 'Costa Rica' (A1Sh2.A1Sh2) and white shrunken2 (sh2) super-sweetcorn 'Tims-white' (a1sh2.a1sh2), however, information regarding anthocyanin biosynthesis genes controlling purple colour and sweetness gene is lacking. Specific sequence differences in the CDS (coding DNA sequence) and promoter regions of the anthocyanin biosynthesis structural genes, anthocyanin1 (A1), purple aleurone1 (Pr1) and regulatory genes, purple plant1 (Pl1), plant colour1 (B1), coloured1 (R1), and the sweetcorn structural gene, shrunken2 (sh2) were investigated using the publicly available annotated yellow starchy maize, B73 (NAM5.0) as a reference genome. In the CDS region, the A1, Pl1 and R1 gene sequence differences of 'Tim1' and 'Costa Rica' were similar, as they control purple-pericarp pigmentation. However, the B1 gene showed similarity between the 'Tim1' and 'Tims-white' lines, which may indicate that it does not have a role in controlling pericarp colour, unlike the report of a previous study. In the case of the Pr1 gene, in contrast to 'Costa Rica', 6- and 8-bp dinucleotide (TA) repeats were observed in the promoter region of the 'Tims-white' and 'Tim1' lines, respectively, indicating the defective functionality (redder colour in 'Tim1' rather than purple in 'Costa Rica') of the recessive pr1 allele. In sweetcorn, the structural gene (sh2), sequence showed similarity between purple-sweet 'Tim1' and its white-sweet parent 'Tims-white', as both display a shrunken phenotype in their mature kernels. These findings revealed that the developed purple-sweet line is different to the reference yellow-nonsweet line in both the anthocyanin biosynthesis and sweetcorn genes.
最近，一种新型的紫色果皮超甜玉米品系“Tim1”（A1A1.sh2sh2）是由紫色果皮玉米“Costa Rica”（A1Sh2.A1Sh2）和白色皱缩 2 号（sh2）超甜玉米“Tims-white”（a1sh2.a1sh2）衍生而来，然而，关于控制紫色和甜味的花青素生物合成基因的信息尚不清楚。使用公开的黄色粉质玉米 B73（NAM5.0）作为参考基因组，研究了花青素生物合成结构基因花青素 1（A1）、紫色糊粉层 1（Pr1）和调控基因紫色植物 1（Pl1）、植物颜色 1（B1）、有色 1（R1）和甜玉米结构基因皱缩 2（sh2）在 CDS（编码 DNA 序列）和启动子区域的特异序列差异。在 CDS 区域，“Tim1”和“Costa Rica”的 A1、Pl1 和 R1 基因序列差异相似，因为它们控制紫色果皮的色素沉着。然而，B1 基因在“Tim1”和“Tims-white”品系之间表现出相似性，这表明它在控制果皮颜色方面可能不起作用，这与之前一项研究的报告不同。在 Pr1 基因方面，与“Costa Rica”不同，“Tims-white”和“Tim1”品系的启动子区域观察到 6-和 8-碱基对（TA）重复，表明隐性 pr1 等位基因的功能缺陷（“Tim1”的颜色较红而不是“Costa Rica”的紫色）。在甜玉米中，结构基因（sh2）的序列在紫色甜“Tim1”及其白色甜亲本“Tims-white”之间相似，因为它们在成熟的籽粒中都表现出皱缩的表型。这些发现表明，所开发的紫色甜玉米品系在花青素生物合成和甜玉米基因方面与参考的黄色非甜玉米品系不同。
