Bandyopadhyay Kaustav, Uluçay Orhan, Şakiroğlu Muhammet, Udvardi Michael K, Verdier Jerome
The Samuel Roberts Noble Foundation, Plant Biology Division, 2510 Sam Noble Parkway, Ardmore, OK 73401, USA.
Kafkas University-Faculty of Engineering and Architecture, Central Campus, Kars 36100, Turkey.
Int J Mol Sci. 2016 Sep 8;17(9):1472. doi: 10.3390/ijms17091472.
Legume seeds are important as protein and oil source for human diet. Understanding how their final seed size is determined is crucial to improve crop yield. In this study, we analyzed seed development of three accessions of the model legume, Medicago truncatula, displaying contrasted seed size. By comparing two large seed accessions to the reference accession A17, we described mechanisms associated with large seed size determination and potential factors modulating the final seed size. We observed that early events during embryogenesis had a major impact on final seed size and a delayed heart stage embryo development resulted to large seeds. We also observed that the difference in seed growth rate was mainly due to a difference in embryo cell number, implicating a role of cell division rate. Large seed accessions could be explained by an extended period of cell division due to a longer embryogenesis phase. According to our observations and recent reports, we observed that auxin (IAA) and abscisic acid (ABA) ratio could be a key determinant of cell division regulation at the end of embryogenesis. Overall, our study highlights that timing of events occurring during early seed development play decisive role for final seed size determination.
豆科植物种子作为人类饮食中蛋白质和油的来源非常重要。了解其最终种子大小是如何决定的对于提高作物产量至关重要。在本研究中，我们分析了三种模式豆科植物蒺藜苜蓿不同种子大小的材料的种子发育情况。通过将两个大种子材料与参考材料A17进行比较，我们描述了与大种子大小决定相关的机制以及调节最终种子大小的潜在因素。我们观察到胚胎发生早期事件对最终种子大小有重大影响，心脏期胚胎发育延迟导致种子变大。我们还观察到种子生长速率的差异主要是由于胚细胞数量的差异，这暗示了细胞分裂速率的作用。大种子材料可以用更长的胚胎发生期导致的细胞分裂延长来解释。根据我们的观察和近期报道，我们发现生长素（IAA）和脱落酸（ABA）的比例可能是胚胎发生末期细胞分裂调控的关键决定因素。总体而言，我们的研究强调了种子早期发育过程中事件的时间安排对最终种子大小的决定起着决定性作用。
