Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, 410128, Hunan, China; College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, 410128, Hunan, China.
J Sci Food Agric. 2013 Dec;93(15):3763-8. doi: 10.1002/jsfa.6254. Epub 2013 Jul 12.
Flowering time is an important agronomic trait, and wide variation in flowering time exists among Brassica napus accessions. GX50 early-flowering mutant, induced from Brassica napus by Ethyl Methane Sulfonate (EMS), exhibits a remarkable early transition from vegetative to reproductive growth.
GX50 plants flowered about 60 days earlier than the control wild-type plant B. napus XY15 under greenhouse conditions. Cytological examination revealed that the GX50 plants form inflorescences as early as from 5 weeks old, flower primordium from 6 weeks old, and siliques from 10 weeks old, whereas 10-week-old XY15 plants are still at vegetative growth stage. To unravel the molecular mechanisms underlying the GX50 flowering phenotype, we analyzed the expression of several key regulatory genes. Expressions of all five BnaFLCs (BnaFLC1 to BnaFLC5), BnaFT and BnaSOC1 were detected. Interestingly, BnaFLCs expression levels were lower in GX50 than those in XY15. Among the five BnaFLCs, only the expression pattern of BnaFLC2 corresponded to the timing of floral organ differentiation in GX50. In agreement with previous knowledge that BnaFLCs repress expression of BnaFT and BnaSOC1, increased levels of BnaFT and BnaSOC1 were observed in GX50 compared with XY15.
BnaFLC2, but not the other BnaFLC genes, plays an important role in B. napus GX50 floral transition.
开花时间是一个重要的农艺性状，甘蓝型油菜品种之间存在广泛的开花时间变异。由乙基磺酸甲酯（EMS）诱导的甘蓝型油菜 GX50 早花突变体表现出从营养生长到生殖生长的显著早期转变。
在温室条件下，GX50 植株比对照野生型油菜 XY15 早开花约 60 天。细胞学检查表明，GX50 植株早在 5 周龄时就形成花序，在 6 周龄时形成花原基，在 10 周龄时形成角果，而 10 周龄的 XY15 植株仍处于营养生长阶段。为了揭示 GX50 开花表型的分子机制，我们分析了几个关键调控基因的表达。检测到五个 BnaFLCs（BnaFLC1 到 BnaFLC5）、BnaFT 和 BnaSOC1 的表达。有趣的是，GX50 中的 BnaFLCs 表达水平低于 XY15。在五个 BnaFLCs 中，只有 BnaFLC2 的表达模式与 GX50 中花器官分化的时间相对应。与 BnaFLCs 抑制 BnaFT 和 BnaSOC1 表达的先前知识一致，在 GX50 中观察到 BnaFT 和 BnaSOC1 的水平升高。
BnaFLC2 而不是其他 BnaFLC 基因，在甘蓝型油菜 GX50 花转变中起重要作用。
