Stability of Single-Parent Gene Expression Complementation in Maize Hybrids upon Water Deficit Stress
Stability of Single-Parent Gene Expression Complementation in Maize Hybrids upon Water Deficit Stress
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DOI：
10.1104/pp.16.01045
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发表时间：
2017-02-01
期刊：
影响因子：
7.4
通讯作者：
Hochholdinger, Frank
中科院分区：
文献类型：
--
作者：
Marcon, Caroline;Paschold, Anja;Hochholdinger, Frank
杂种优势是指杂种F1与其纯合的、遗传上不同的亲本相比的上级表现。在这项研究中，我们监测了玉米（Zea mays）自交系B73和Mo17及其正反交F1杂交后代在控制和水分亏缺条件下的初级根转录组分化模拟聚乙二醇处理。基因的单亲表达（SPE）是基因表达互补的一个极端例子，其中基因在两个亲本中只有一个是活跃的，但在两个相互杂交中表达。在这项研究中，仅在B73中表达的1，997个基因和仅在Mo 17中表达的2，024个基因在对照和缺水条件下表现出SPE互补。因此，杂交种中活性基因的数量超过亲本近交系中活性基因的数量，与处理显著无关。SPE模式实质上更稳定的表达变化，水分亏缺处理比其他基因型特异性表达谱。虽然，平均而言，75%的所有SPE模式没有改变聚乙二醇治疗的反应，只有17%的剩余的基因型特异性表达模式没有改变水分亏缺。非同线基因，缺乏同线的直系同源物在其他草种，从而在草的血统，进化后期，显着偏高的SPE基因。因此，显着的高表达的非同线基因之间的SPE模式和它们的稳定性下水分限制可能表明这些基因的功能，在早期发育表现杂种优势在波动的环境条件下，在自交系B73和Mo17的杂交后代。
Heterosis is the superior performance of F1 hybrids compared with their homozygous, genetically distinct parents. In this study, we monitored the transcriptomic divergence of the maize (Zea mays) inbred lines B73 and Mo17 and their reciprocal F1 hybrid progeny in primary roots under control and water deficit conditions simulated by polyethylene glycol treatment. Single-parent expression (SPE) of genes is an extreme instance of gene expression complementation, in which genes are active in only one of two parents but are expressed in both reciprocal hybrids. In this study, 1,997 genes only expressed in B73 and 2,024 genes only expressed in Mo17 displayed SPE complementation under control and water deficit conditions. As a consequence, the number of active genes in hybrids exceeded the number of active genes in the parental inbred lines significantly independent of treatment. SPE patterns were substantially more stable to expression changes by water deficit treatment than other genotype-specific expression profiles. While, on average, 75% of all SPE patterns were not altered in response to polyethylene glycol treatment, only 17% of the remaining genotype-specific expression patterns were not changed by water deficit. Nonsyntenic genes that lack syntenic orthologs in other grass species, and thus evolved late in the grass lineage, were significantly overrepresented among SPE genes. Hence, the significant overrepresentation of nonsyntenic genes among SPE patterns and their stability under water limitation might suggest a function of these genes during the early developmental manifestation of heterosis under fluctuating environmental conditions in hybrid progeny of the inbred lines B73 and Mo17.