When genomes collide: aberrant seed development following maize interploidy crosses.
When genomes collide: aberrant seed development following maize interploidy crosses.
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DOI：
10.1093/aob/mcn017
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发表时间：
2008-04
期刊：
影响因子：
4.2
通讯作者：
Paul D Pennington;Liliana M. Costa;J. Gutierrez-Marcos;A. Greenland;H. Dickinson
中科院分区：
文献类型：
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作者：
Paul D Pennington;Liliana M. Costa;J. Gutierrez-Marcos;A. Greenland;H. Dickinson
背景与目的被子植物异倍性或倍性间杂交的结果是不可预测的，常常导致种子败育。在玉米中已经详细地探索了互异倍性杂交的后果，重点是玉米胚乳中组织结构域的改变和胚乳特异性基因表达的变化。方法利用玉米二倍体和四倍体进行异倍性杂交，利用GUS报告基因研究胚乳结构域的发育，并利用半定量RT-PCR技术研究不同发育阶段胚乳中基因的表达。关键结果：互异倍性杂交导致非常小的，大部分不育的种子，胚乳有缺陷。具有母本基因组过量的种子比具有父本基因组过量的种子小，其胚乳细胞化更早，并且它们积累大量的淀粉。正反交的胚乳细胞增殖期延长，淀粉积累较少。报告系和基因表达研究的分析证实，胚乳的功能结构域被严重破坏，并根据倍性间杂交的方向进行不同的修饰。结论：倍体间杂交影响胚乳细胞增殖和分化平衡的调节因子。特别是，不平衡的玉米杂交影响转移细胞分化，并导致胚乳发育的个体发生程序的时间失调。
BACKGROUND AND AIMS The results of wide- or interploidy crosses in angiosperms are unpredictable and often lead to seed abortion. The consequences of reciprocal interploidy crosses have been explored in maize in detail, focusing on alterations to tissue domains in the maize endosperm, and changes in endosperm-specific gene expression. METHODS Following reciprocal interploidy crosses between diploid and tetraploid maize lines, development of endosperm domains was studied using GUS reporter lines, and gene expression in resulting kernels was investigated using semi-quantitative RT-PCR on endosperms isolated at different stages of development. KEY RESULTS Reciprocal interploidy crosses result in very small, largely infertile seeds with defective endosperms. Seeds with maternal genomic excess are smaller than those with paternal genomic excess, their endosperms cellularize earlier and they accumulate significant quantities of starch. Endosperms from the reciprocal cross undergo an extended period of cell proliferation, and accumulate little starch. Analysis of reporter lines and gene expression studies confirm that functional domains of the endosperm are severely disrupted, and are modified differently according to the direction of the interploidy cross. CONCLUSIONS Interploidy crosses affect factors which regulate the balance between cell proliferation and cell differentiation within the endosperm. In particular, unbalanced crosses in maize affect transfer cell differentiation, and lead to the temporal deregulation of the ontogenic programme of endosperm development.