Australian Research Council Centre of Excellence for Integrative Legume Research, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, 2308, Australia.
Plant Cell Rep. 2014 Feb;33(2):349-62. doi: 10.1007/s00299-013-1535-x. Epub 2013 Nov 22.
Cultivated legumes account for more than a quarter of primary crop production worldwide. The protein- and oil-rich seed of cultivated legumes provides around one-third of the protein in the average human diet, with soybeans (Glycine max (L.) Merr) being the single largest source of vegetable oil. Despite their critical importance to human and animal nutrition, we lack an understanding of how early seed development in legumes is orchestrated at the transcriptional level. We developed a method to isolate ovules from the model legume, Medicago truncatula Gaertn, at specific stages of embryogenesis, on the basis of flower and pod morphology. Using these isolated ovules we profiled the expression of candidate homeobox, AP2 domain and B3 domain-containing transcription factors. These genes were identified by available information and sequence homology, and five distinctive patterns of transcription were found that correlated with specific stages of early seed growth and development. Co-expression of some genes could be related to common regulatory sequences in the promoter or 3'-UTR regions. These expression patterns were also related to the expression of B3-domain transcription factors important in seed filling (MtFUS3-like and MtABI3-like). Localisation of gene expression by promoter-GUS fusions or in situ hybridisation aided understanding of the role of the transcription factors. This study provides a framework to enhance the understanding of the integrated transcriptional regulation of legume embryo growth and development and seed filling.
栽培豆类作物在全球主要作物产量中占比超过四分之一。栽培豆类作物富含蛋白质和油脂的种子为人类饮食提供了约三分之一的蛋白质，其中大豆（Glycine max (L.) Merr）是蔬菜油的最大单一来源。尽管豆类作物对人类和动物营养至关重要，但我们仍不了解豆类作物早期种子发育在转录水平上是如何协调的。我们基于花和荚果的形态，开发了一种从模式豆科植物蒺藜苜蓿（Medicago truncatula Gaertn）中分离胚胎发生特定阶段胚珠的方法。我们使用这些分离的胚珠，对候选同源盒、AP2 结构域和 B3 结构域包含转录因子的表达进行了分析。这些基因是根据现有信息和序列同源性确定的，发现了五种与早期种子生长和发育特定阶段相关的独特转录模式。一些基因的共表达可能与启动子或 3'-UTR 区域中的共同调节序列有关。这些表达模式也与在种子填充中起重要作用的 B3 结构域转录因子（MtFUS3 样和 MtABI3 样）的表达有关。启动子-GUS 融合或原位杂交的基因表达定位有助于理解转录因子的作用。本研究为增强对豆类胚胎生长和发育以及种子填充的综合转录调控的理解提供了框架。
