Wang Xiaobo, Li Yinhui, Zhang Haowei, Sun Genlou, Zhang Wenming, Qiu Lijuan
College of Agronomy, Anhui Agricultural University, Hefei, 230036, China,
Mol Biol Rep. 2015 Feb;42(2):489-96. doi: 10.1007/s11033-014-3792-3. Epub 2014 Oct 17.
Seed-size/weight traits, controlled by multiple genes in soybean, play an important role in determining seed yield. However, the molecular mechanisms controlling the seed size and weight in soybean remain unclear. In Arabidopsis, P450/CYP78A gene family has been proved extremely relevant to seed size (such as AtCYP78A5, AtCYP78A6 and AtCYP78A9). We found that a soybean GmCYP78A10 gene underwent artificial selection during soybean breeding. The GmCYP78A10a allele mainly distributed in wild soybean (Glycine soja), but has been eliminated in the cultivars during early stage of soybean breeding, while the GmCYP78A10b allele has been accumulated and become the predominant allele in cultivated soybean (G. max). ANOVA analysis showed that the mean seed weight, seed width and seed thickness of soybean varieties with GmCYP78A10b allele was significantly heavier/bigger than those with GmCYP78A10a allele (P < 0.01). The allele could explain 7.2 % variation in seed weight. The pod number of the soybeans with GmCYP78A10b allele significantly decreased compared to those with GmCYP78A10a allele (P < 0.01, R(2) = 5.8 %), while other agronomic traits including seed weight/plant were not significantly affected by these two alleles. We speculated that during the early stage of soybean breeding, breeders selected big seed carrying GmCYP78A10b allele, but lowered pod number simultaneously. Overall, the selection did not cause the significantly change in soybean seed yield. Our results suggests that the soybean GmCYP78A10 gene may have a similar function to those genes belonging to P450/CYP78A subfamily in Arabidopsis and provides new information for the genetic control of seed size in soybean.
种子大小/重量性状由大豆中的多个基因控制，在决定种子产量方面发挥着重要作用。然而，控制大豆种子大小和重量的分子机制仍不清楚。在拟南芥中，P450/CYP78A基因家族已被证明与种子大小密切相关（如AtCYP78A5、AtCYP78A6和AtCYP78A9）。我们发现，大豆GmCYP78A10基因在大豆育种过程中经历了人工选择。GmCYP78A10a等位基因主要分布在野生大豆（野大豆）中，但在大豆育种早期已在栽培品种中被淘汰，而GmCYP78A10b等位基因则得以积累并成为栽培大豆（大豆）中的主要等位基因。方差分析表明，具有GmCYP78A10b等位基因的大豆品种的平均种子重量、种子宽度和种子厚度显著高于具有GmCYP78A10a等位基因的品种（P < 0.01）。该等位基因可解释种子重量7.2%的变异。与具有GmCYP78A10a等位基因的大豆相比，具有GmCYP78A10b等位基因的大豆的荚果数显著减少（P < 0.01，R(2) = 5.8%），而包括单株种子重量在内的其他农艺性状不受这两个等位基因的显著影响。我们推测，在大豆育种早期，育种者选择了携带GmCYP78A10b等位基因的大种子，但同时降低了荚果数。总体而言，这种选择并未导致大豆种子产量的显著变化。我们的结果表明，大豆GmCYP78A10基因可能与拟南芥中属于P450/CYP78A亚家族的那些基因具有相似的功能，并为大豆种子大小的遗传控制提供了新的信息。
