Centro de Genómica e Biotecnologia, Instituto de Biotecnologia e Bioengenharia (CGB/IBB), Universidade de Trás-os-Montes e Alto Douro (UTAD), P,O, Box 1013, 5001-801 Vila Real, Portugal.
BMC Plant Biol. 2013 Sep 13;13:134. doi: 10.1186/1471-2229-13-134.
Aluminium (Al) toxicity is considered to be one of the major constraints affecting crop productivity on acid soils. Being a trait governed by multiple genes, the identification and characterization of novel transcription factors (TFs) regulating the expression of entire response networks is a very promising approach. Therefore, the aim of the present study was to clone, localize, and characterize the TaSTOP1 gene, which belongs to the zinc finger family (Cys2His2 type) transcription factor, at molecular level in bread wheat.
TaSTOP1 loci were cloned and localized on the long arm of homoeologous group 3 chromosomes [3AL (TaSTOP1-A), 3BL (TaSTOP1-B) and 3DL (TaSTOP1-D)] in bread wheat. TaSTOP1 showed four potential zinc finger domains and the homoeologue TaSTOP1-A exhibited transactivation activity in yeast. Expression profiling of TaSTOP1 transcripts identified the predominance of homoeologue TaSTOP1-A followed by TaSTOP1-D over TaSTOP1-B in root and only predominance of TaSTOP1-A in shoot tissues of two diverse bread wheat genotypes. Al and proton (H(+)) stress appeared to slightly modulate the transcript of TaSTOP1 homoeologues expression in both genotypes of bread wheat.
Physical localization of TaSTOP1 results indicated the presence of a single copy of TaSTOP1 on homoeologous group 3 chromosomes in bread wheat. The three homoeologues of TaSTOP1 have similar genomic structures, but showed biased transcript expression and different response to Al and proton (H(+)) toxicity. These results indicate that TaSTOP1 homoeologues may differentially contribute under Al or proton (H(+)) toxicity in bread wheat. Moreover, it seems that TaSTOP1-A transactivation potential is constitutive and may not depend on the presence/absence of Al at least in yeast. Finally, the localization of TaSTOP1 on long arm of homoeologous group 3 chromosomes and the previously reported major loci associated with Al resistance at chromosome 3BL, through QTL and genome wide association mapping studies suggests that TaSTOP1 could be a potential candidate gene for genomic assisted breeding for Al tolerance in bread wheat.
铝（Al）毒性被认为是影响酸性土壤作物生产力的主要限制因素之一。由于该性状受多个基因控制，因此鉴定和表征调节整个响应网络表达的新型转录因子（TFs）是一种非常有前途的方法。因此，本研究的目的是在分子水平上克隆、定位和表征属于锌指家族（Cys2His2 型）转录因子的 TaSTOP1 基因，该基因在普通小麦中。
TaSTOP1 基因座在普通小麦同源群 3 号染色体的长臂上被克隆和定位[3AL（TaSTOP1-A）、3BL（TaSTOP1-B）和 3DL（TaSTOP1-D）]。TaSTOP1 显示出四个潜在的锌指结构域，同源 TaSTOP1-A 在酵母中表现出转录激活活性。TaSTOP1 转录本的表达谱分析表明，在两个不同的普通小麦基因型的根中，同源 TaSTOP1-A 优先于 TaSTOP1-B，而仅在 shoot 组织中优先于 TaSTOP1-A。Al 和质子（H(+））胁迫似乎略微调节两个普通小麦基因型中 TaSTOP1 同源物表达的转录。
TaSTOP1 的物理定位结果表明，普通小麦同源群 3 号染色体上存在 TaSTOP1 的单个拷贝。TaSTOP1 的三个同源物具有相似的基因组结构，但表现出偏转录表达，对 Al 和质子（H(+））毒性的反应不同。这些结果表明，TaSTOP1 同源物可能在 Al 或质子（H(+））毒性下在普通小麦中差异贡献。此外，TaSTOP1-A 的转录激活潜力似乎是组成型的，至少在酵母中可能不依赖于 Al 的存在/不存在。最后，TaSTOP1 在同源群 3 号染色体长臂上的定位以及先前报道的与 3BL 染色体上 Al 抗性相关的主要基因座通过 QTL 和全基因组关联图谱研究表明，TaSTOP1 可能是普通小麦 Al 耐性基因组辅助育种的潜在候选基因。
