Molecular dissection of heterosis manifestation during early maize root development
Molecular dissection of heterosis manifestation during early maize root development
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DOI：
10.1007/s00122-009-1082-6
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发表时间：
2010-01-01
影响因子：
5.4
通讯作者：
Hochholdinger, Frank
中科院分区：
文献类型：
--
作者：
Paschold, Anja;Marcon, Caroline;Hochholdinger, Frank
杂种优势是重要的农艺性状，在玉米杂交育种中已成功利用了几十年。然而，杂种优势的分子基础仍然难以捉摸。杂种优势不仅在产量或株高等成株性状中观察到，而且在胚胎和幼苗发育过程中就已经检测到。因此，玉米（Zea mays L.）初生根是种子萌发后第一个长出的器官，是研究杂种优势表现的理想模型。幼苗根系性状如主根长、侧根密度等均表现出杂种优势。微阵列研究表明玉米杂交种非加性基因表达的器官特异性模式。此外，这样的实验支持这样的概念，即玉米初生根中的全局表达趋势在不同杂交种之间是保守的。此外，超氧化物歧化酶2等特定基因的非加性表达模式可能有助于杂种优势的早期表现。玉米杂交种初生根的蛋白质组分析实验揭示了与相应RNA谱不同的非加性积累模式，强调了转录后过程的重要性，如可能与杂种优势相关的蛋白质修饰。最后，选定的代谢产物的分析意味着，一个微妙的调节特定的生化途径，如苯丙烷类途径在杂交种可能有助于表现在玉米初生根的杂种优势。在未来，最近开发的分子工具将有助于分析玉米根系杂种优势的分子基础。
Heterosis is of paramount agronomic importance and has been successfully exploited in maize hybrid breeding for decades. Nevertheless, the molecular basis of heterosis remains elusive. Heterosis is not only observed in adult traits like yield or plant height, but is already detected during embryo and seedling development. Hence, the maize (Zea mays L.) primary root which is the first organ that emerges after germination is a suitable model to study heterosis manifestation. Various seedling root traits including primary root length and lateral root density display heterosis. Microarray studies suggest organ specific patterns of nonadditive gene expression in maize hybrids. Moreover, such experiments support the notion that global expression trends in maize primary roots are conserved between different hybrids. Furthermore, nonadditive expression patterns of specific genes such as a SUPEROXIDE DISMUTASE 2 might contribute to the early manifestation of heterosis. Proteome profiling experiments of maize hybrid primary roots revealed nonadditive accumulation patterns that were distinct from the corresponding RNA profiles underscoring the importance of posttranscriptional processes such as protein modifications that might be related to heterosis. Finally, analysis of selected metabolites imply that a subtle regulation of particular biochemical pathways such as the phenylpropanoid pathway in hybrids might contribute to the manifestation of heterosis in maize primary roots. In the future, recently developed molecular tools will facilitate the analysis of the molecular principles underlying heterosis in maize roots.