Plant Molecular Biology and Biotechnology Laboratory, ARC Centre of Excellence for Integrative Legume Research, Melbourne School of Land and Environment, The University of Melbourne, Parkville, Victoria 3010, Australia.
BMC Plant Biol. 2013 Jul 20;13:105. doi: 10.1186/1471-2229-13-105.
The classical (C) MIKC-type MADS-box transcription factors comprise one gene family that plays diverse roles in the flowering process ranging from floral initiation to the development of floral organs. Despite their importance in regulating developmental processes that impact crop yield, they remain largely unexplored in the major legume oilseed crop, soybean.
We identified 57 MIKC(c)-type transcription factors from soybean and determined the in silico gene expression profiles of the soybean MIKC(c)-type genes across different tissues. Our study implicates three MIKC(c)-type transcription factors as novel members of the AGAMOUS LIKE 6 (AGL6) subfamily of the MIKC(C)-type MADS-box genes, and we named this sister clade PsMADS3. While similar genes were identified in other legume species, poplar and grape, no such gene is represented in Arabidopsis thaliana or rice. RT-PCR analysis on these three soybean PsMADS3 genes during early floral initiation processes revealed their temporal expression similar to that of APETALA1, a gene known to function as a floral meristem identity gene. However, RNA in situ hybridisation showed that their spatial expression patterns are markedly different from those of APETALA1.
Legume flower development system differs from that in the model plant, Arabidopsis. There is an overlap in the initiation of different floral whorls in soybean, and inflorescent meristems can revert to leaf production depending on the environmental conditions. MIKC(C)-type MADS-box genes have been shown to play key regulatory roles in different stages of flower development. We identified members of the PsMADS3 sub-clade in legumes that show differential spatial expression during floral initiation, indicating their potential novel roles in the floral initiation process. The results from this study will contribute to a better understanding of legume-specific floral developmental processes.
经典（C）MIKC 型 MADS 盒转录因子组成了一个基因家族，在开花过程中发挥着多样化的作用，从花的起始到花器官的发育。尽管它们在调节影响作物产量的发育过程中很重要，但在主要的豆科油料作物大豆中，它们在很大程度上仍未被探索。
我们从大豆中鉴定了 57 个 MIKC(c)-型转录因子，并确定了大豆 MIKC(c)-型基因在不同组织中的基因表达图谱。我们的研究表明，三个 MIKC(c)-型转录因子是 AGAMOUS LIKE 6（AGL6）亚家族的新成员，我们将这个姐妹枝命名为 PsMADS3。虽然在其他豆科植物、杨树和葡萄中也鉴定出了类似的基因，但在拟南芥或水稻中则没有这样的基因。对这三个大豆 PsMADS3 基因在早期花起始过程中的 RT-PCR 分析表明，它们的表达时间与作为花分生组织身份基因的 APETALA1 相似。然而，RNA 原位杂交显示，它们的空间表达模式与 APETALA1 明显不同。
豆科植物的花发育系统与模式植物拟南芥不同。大豆中不同花轮的起始有重叠，并且根据环境条件，花序分生组织可以恢复为叶片产生。MIKC(C)-型 MADS 盒基因在花发育的不同阶段发挥着关键的调节作用。我们在豆科植物中鉴定了 PsMADS3 亚族的成员，它们在花起始期间表现出不同的空间表达，表明它们在花起始过程中具有潜在的新作用。这项研究的结果将有助于更好地理解豆科植物特有的花发育过程。
