Guo Dongliang, Jiang Haixia, Xie Liqiong
Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi 830017, China.
Key Laboratory of Plant Stress Biology in Arid Land, College of Life Science, Xinjiang Normal University, Urumqi 830017, China.
Genes (Basel). 2024 Apr 18;15(4):511. doi: 10.3390/genes15040511.
The loss of anthocyanin pigments is one of the most common evolutionary transitions in petal color, yet the genetic basis for these changes in flax remains largely unknown. In this study, we used crossing studies, a bulk segregant analysis, genome-wide association studies, a phylogenetic analysis, and transgenic testing to identify genes responsible for the transition from blue to white petals in flax. This study found no correspondence between the petal color and seed color, refuting the conclusion that a locus controlling the seed coat color is associated with the petal color, as reported in previous studies. The locus controlling the petal color was mapped using a BSA-seq analysis based on the F population. However, no significantly associated genomic regions were detected. Our genome-wide association study identified a highly significant QTL () on chromosome 4 associated with flax petal color in the natural population. The combination of a local Manhattan plot and an LD heat map identified , an R2R3-MYB transcription factor, as a potential gene responsible for the natural variations in petal color in flax. The overexpression of in both and resulted in anthocyanin deposition, indicating that is a credible candidate gene for controlling the petal color in flax. Additionally, our study highlights the limitations of the BSA-seq method in low-linkage genomic regions, while also demonstrating the powerful detection capabilities of GWAS based on high-density genomic variation mapping. This study enhances our genetic insight into petal color variations and has potential breeding value for engineering to develop colored petals, bast fibers, and seeds for multifunctional use in flax.
花青素色素的丧失是花瓣颜色最常见的进化转变之一，但亚麻中这些变化的遗传基础在很大程度上仍不清楚。在本研究中，我们使用杂交研究、群体分离分析法、全基因组关联研究、系统发育分析和转基因测试来鉴定亚麻中负责花瓣从蓝色转变为白色的基因。本研究发现花瓣颜色与种子颜色之间没有对应关系，这与先前研究报道的控制种皮颜色的基因座与花瓣颜色相关的结论相矛盾。基于F群体，使用群体分离分析法测序（BSA-seq）绘制了控制花瓣颜色的基因座。然而，未检测到显著相关的基因组区域。我们的全基因组关联研究在自然群体中鉴定出一个与亚麻花瓣颜色相关的位于4号染色体上的高度显著的数量性状位点（QTL）。局部曼哈顿图和连锁不平衡（LD）热图的结合确定了一个R2R3-MYB转录因子，作为亚麻花瓣颜色自然变异的潜在基因。在拟南芥和烟草中过表达该基因均导致花青素沉积，表明该基因是控制亚麻花瓣颜色的可靠候选基因。此外，我们的研究突出了BSA-seq方法在低连锁基因组区域的局限性，同时也证明了基于高密度基因组变异图谱的全基因组关联研究的强大检测能力。本研究增强了我们对花瓣颜色变异的遗传认识，并且对于通过基因工程培育具有彩色花瓣、韧皮纤维和种子以实现亚麻多功能利用具有潜在的育种价值。
