Department of Genetics, Faculty of Biology, Complutense University of Madrid, Madrid, Spain.
Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.
Plant Biol (Stuttg). 2018 Sep;20(5):817-824. doi: 10.1111/plb.12864. Epub 2018 Jul 17.
Recently, members of the MATE family have been implicated in aluminium (Al) tolerance by facilitating citrate efflux in plants. The aim of the present work was to perform a molecular characterisation of the MATE2 gene in bread wheat. Here, we cloned a member of the MATE gene family in bread wheat and named it TaMATE2, which showed the typical secondary structure of MATE-type transporters maintaining all the 12 transmembrane domains. Amplification in Chinese Spring nulli-tetrasomic and ditelosomic lines revealed that TaMATE2 is located on the long arm of homoeologous group 1 chromosomes. The transcript expression of TaMATE2 homoeologues in two diverse bread wheat genotypes, Barbela 7/72/92 (Al-tolerant) and Anahuac (Al-sensitive), suggested that TaMATE2 is expressed in both root and shoot tissues of bread wheat, but mainly confined to root rather than shoot tissues. A time-course analysis of TaMATE2 homoeologue transcript expression revealed the Al responsive expression of TaMATE2 in root apices of the Al-tolerant genotype, Barbela 7/72/92. Considering the high similarity of TaMATE2 together with similar Al responsive expression pattern as of ScFRDL2 from rye and OsFRDL2 from rice, it is likely that TaMATE2 also encodes a citrate transporter. Furthermore, the TaMATE2-D homoeologue appears to be near the previously reported locus (wPt0077) on chromosome 1D for Al tolerance. In conclusion, molecular cloning of TaMATE2 homoeologues, particularly TaMATE2-D, provides a plausible candidate for Al tolerance in bread wheat that can be used for the development of more Al-tolerant cultivars in this staple crop.
最近，MATE 家族的成员被认为通过促进植物中的柠檬酸外排来耐受铝（Al）。本工作的目的是对小麦中的 MATE2 基因进行分子特征分析。在这里，我们克隆了小麦 MATE 基因家族的一个成员，并将其命名为 TaMATE2，它表现出 MATE 型转运蛋白的典型二级结构，保持所有 12 个跨膜结构域。在 Chinese Spring 缺四体和双端体系中的扩增表明，TaMATE2 位于同源群 1 染色体的长臂上。在两个不同的小麦基因型 Barbela 7/72/92（耐 Al）和 Anahuac（Al 敏感）中，TaMATE2 同源基因的转录表达表明 TaMATE2 表达于小麦的根和茎组织中，但主要局限于根组织而不是茎组织。TaMATE2 同源基因转录表达的时间进程分析表明，在耐 Al 基因型 Barbela 7/72/92 的根顶端，TaMATE2 对 Al 有响应表达。考虑到 TaMATE2 与黑麦 ScFRDL2 和水稻 OsFRDL2 具有高度相似性，以及类似的 Al 响应表达模式，TaMATE2 很可能也编码一种柠檬酸转运蛋白。此外，TaMATE2-D 同源基因似乎靠近先前报道的染色体 1D 上的 Al 耐受位点（wPt0077）。总之，TaMATE2 同源基因的分子克隆，特别是 TaMATE2-D，为小麦的 Al 耐受提供了一个合理的候选基因，可用于开发这种主要作物的更耐 Al 品种。
