PDF(Pubmed)
Abstract：
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 F2 population. However, no significantly associated genomic regions were detected. Our genome-wide association study identified a highly significant QTL (BP4.1) 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 LuMYB314, an R2R3-MYB transcription factor, as a potential gene responsible for the natural variations in petal color in flax. The overexpression of LuMYB314 in both Arabidopsis thaliana and Nicotiana tabacum resulted in anthocyanin deposition, indicating that LuMYB314 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 LuMYB314 to develop colored petals, bast fibers, and seeds for multifunctional use in flax.
摘要：
花青素色素的丧失是花瓣颜色最常见的进化转变之一，然而，亚麻这些变化的遗传基础仍然很大程度上未知。在这项研究中,我们使用了交叉研究，大量的分离分析，全基因组关联研究，系统发育分析，和转基因测试，以确定负责亚麻从蓝色到白色花瓣过渡的基因。这项研究发现花瓣颜色和种子颜色之间没有对应关系，驳斥了控制种皮颜色的轨迹与花瓣颜色相关的结论，正如以前的研究报道的那样。使用基于F2种群的BSA-seq分析来绘制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确定了天然种群中4号染色体上与亚麻花瓣颜色相关的高度显着的QTL（BP4.1）。曼哈顿本地地块和LD热图的结合确定了R2R3-MYB转录因子LuMYB314，作为负责亚麻花瓣颜色自然变化的潜在基因。LuMYB314在拟南芥和烟草中的过表达导致花青素沉积，表明LuMYB314是控制亚麻花瓣颜色的可靠候选基因。此外,我们的研究强调了BSA-seq方法在低连锁基因组区域的局限性，同时也证明了GWAS基于高密度基因组变异作图的强大检测能力。这项研究增强了我们对花瓣颜色变化的遗传洞察力，并对工程LuMYB314开发彩色花瓣具有潜在的育种价值，韧皮纤维,和种子用于亚麻的多功能用途。
