Molecular characterization of the allelic variation at the VRN-H2 vernalization locus in barley
Molecular characterization of the allelic variation at the VRN-H2 vernalization locus in barley
复制标题
DOI：
10.1007/s11032-005-0084-6
复制
发表时间：
2005-05-01
影响因子：
3.1
通讯作者：
Yan, LL
中科院分区：
文献类型：
--
作者：
Dubcovsky, J;Chen, CL;Yan, LL
VRN-2是一个显性的开花抑制因子，在小麦春化过程中起着核心作用。该基因是一个受春化下调的锌指/CCT结构域转录因子(ZCCT-1)。在大麦中存在3个相关和连锁的ZCCT基因，分别命名为VRN-H1a、b和c。从冬用大麦品种‘Chikurin Ibaraki I’的6个可能的春季诱变突变体中观察到这3个基因的缺失。然而，对其他分子标记的分析表明，这些缺失是由一个携带自然ZCCT缺失的春大麦品种异交产生的。84个大麦品种的Southern blot与小麦ZCCT1探针杂交，有23个冬小麦品种有3个或3个以上的片段，而在61个VRN-H2春品种中有60个没有。VRN-H2春大麦品种‘繁’只有ZCCT-Hb基因，表明该基因不足以决定大麦的冬季生长习性。本研究还表明，在大麦分离群体中，当存在显性的VRN-H1等位基因时，VRN-H2对开花时间的影响完全消失。对于二倍体小麦中直源基因之间的上位性互作，以前描述了一个不同的结果。我们讨论了这些差异的可能原因。
VRN-2 is a dominant repressor of flowering that plays a central role in the vernalization pathway of wheat. This gene is a zinc-finger/CCT domain transcription factor (ZCCT-1) down-regulated by vernalization. In barley, there are three related and linked ZCCT genes designated VRN-H1a, b, and c. A deletion of these three genes was observed in six putative spring induced mutants from winter barley variety 'Chikurin Ibaraki I'. However, analysis of additional molecular markers demonstrated that these deletions were originated by outcrossing with a spring barley variety carrying the natural ZCCT deletion. Hybridization of Southern blots from 84 barley varieties with a wheat ZCCT1 probe showed three or more fragments in 23 winter varieties but none in 60 out of the 61 vrn-H2 spring varieties. The vrn-H2-spring barley variety 'Fan' showed only the ZCCT-Hb gene, suggesting that this gene is not sufficient to determine winter growth habit in barley. We also show in this study, that the effect of VRN-H2 on flowering time completely disappears in the presence of the dominant Vrn-H1 allele in a Morex x Hordeum spontaneum segregating population. A different result was described before for the epistatic interactions between the orthologous genes in diploid wheat. We discuss the possible causes of these differences.