The barley (Hordeum vulgare L.) dehydrin multigene family:: sequences, allele types, chromosome assignments, and expression characteristics of 11 Dhn genes of cv Dicktoo
The barley (Hordeum vulgare L.) dehydrin multigene family:: sequences, allele types, chromosome assignments, and expression characteristics of 11 Dhn genes of cv Dicktoo
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DOI：
10.1007/s001220051189
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发表时间：
1999-06-01
影响因子：
5.4
通讯作者：
Close, TJ
中科院分区：
文献类型：
--
作者：
Choi, DW;Zhu, B;Close, TJ
在高等植物和低等植物中都发现了脱水素（莱亚D11蛋白），它与对低温或脱水的耐受性或响应有关。一些研究表明，Dhn基因的特定等位基因可能有助于许多表型性状，包括在凉爽或盐碱土壤中出苗以及更成熟植物的抗冻性。然而，在任何系统中Dhn多基因家族的不完整收集和Dhn基因家族成员之间的核酸交叉杂交限制了这些研究的精确性。我们试图克服这些障碍，通过确定整个Dhn多基因家族在大麦的核苷酸序列，并通过开发基因特异性探针。我们鉴定了11个独特的Dicktoo Dhn基因。7个似乎是以前在其他大麦品种中鉴定的Dhn基因的等位基因。另一个，Dhn 9，似乎是直向的硬粒小麦Dhn基因。对基因组克隆的总收集的统计分析使大麦Dhn基因家族的估计大小达到13。蛋白质编码区的等位基因差异似乎主要是由于整个Phi片段或单个氨基酸取代的重复，这表明多肽结构限制在Dhn等位基因的进化中一直是一个强大的力量。通过对小麦-大麦异附加系的PCR定位，确定了Dhn基因存在于4条大麦染色体（3 H，4 H，5 H，6 H）上。RT-PCR结果表明，Dhn基因在脱水、低温和阿坝处理条件下均受到不同程度的调控，这与Dhn编码区上游的调控元件一致。这种全基因组，基因特异性的研究统一了以前似乎是在小麦族和其他植物系统中的Dhn基因的重复定位，表达和遗传变异数据。
Dehydrins (LEA D11 proteins) have been identified in both higher and lower plants, and are associated with tolerance to, or response to the onset of, low temperature or dehydration. Several studies have suggested that specific alleles of Dhn genes may contribute to a number of phenotypic traits, including the emergence of seedlings in cool or saline soils and the frost tolerance of more-mature plants. However, an incomplete collection of the Dhn multigene family in any system and nucleic acid cross-hybridization between Dhn gene-family members have limited the precision of these studies. We attempted to overcome these impediments by determining the nucleotide sequences of the entire Dhn multigene family in barley and by developing gene-specific probes. We identified 11 unique Dicktoo Dhn genes. Seven appear to be alleles of Dhn genes identified previously in other barley cultivars. Another, Dhn9, appears to be orthologous to a Triticum durum Dhn gene. A statistical analysis of the total collection of genomic clones brings the estimated size of the barley Dhn gene family to 13. Allelic differences in the protein-coding regions appear to result principally from duplications of entire Phi-segments or single amino-acid substitutions, suggesting that polypeptide structural constraints have been a strong force in the evolution of Dhn alleles. Chromosome mapping by PCR with wheat-barley addition lines established the presence of Dhn genes in four barley chromosomes (3H, 4H, 5H, 6H). RT-PCR demonstrated that the Dhn genes are differentially regulated under dehydration, low temperature and ABA treatment, consistent with putative regulatory elements located upstream of the respective Dhn coding regions. This whole-genome, gene-specific study unifies what previously seemed to be disparate-mapping, expression, and genetic-variation data for Dhn genes in the Triticeae and other plant systems.