Yousfi Fatma-Ezzahra, Makhloufi Emna, Marande William, Ghorbel Abdel W, Bouzayen Mondher, Bergès Hélène
Laboratory of Plant Molecular Physiology, Center of Biotechnology of Borj Cedria, Borj Cedria Science and Technology ParkHammam-lif, Tunisia; Centre National de Ressources Genomiques Vegetales, French Plant Genomic Center, INRA-CNRGVCastanet-Tolosan, France; INRA, UMR990 Genomique et Biotechnologie des FruitsCastanet-Tolosan, France.
Laboratory of Plant Molecular Physiology, Center of Biotechnology of Borj Cedria, Borj Cedria Science and Technology ParkHammam-lif, Tunisia; Centre National de Ressources Genomiques Vegetales, French Plant Genomic Center, INRA-CNRGVCastanet-Tolosan, France; INRA, UMR990 Genomique et Biotechnologie des FruitsCastanet-Tolosan, France; INPT, Laboratoire de Genomique et Biotechnologie des Fruits, University of ToulouseCastanet-Tolosan, France.
Front Plant Sci. 2017 Jan 31;7:2034. doi: 10.3389/fpls.2016.02034. eCollection 2016.
WRKY transcription factors are involved in multiple aspects of plant growth, development and responses to biotic stresses. Although they have been found to play roles in regulating plant responses to environmental stresses, these roles still need to be explored, especially those pertaining to crops. Durum wheat is the second most widely produced cereal in the world. Complex, large and unsequenced genomes, in addition to a lack of genomic resources, hinder the molecular characterization of tolerance mechanisms. This paper describes the isolation and characterization of five genes from durum wheat (. ssp. ). A PCR-based screening of a BAC genomic library using primers within the conserved region of genes resulted in the isolation of five BAC clones. Following sequencing fully the five BACs, fine annotation through Triannot pipeline revealed 74.6% of the entire sequences as transposable elements and a 3.2% gene content with genes organized as islands within oceans of TEs. Each BAC clone harbored a gene. The study showed a very extensive conservation of genomic structure between TdWRKYs and their orthologs from Brachypodium, barley, and . The structural features of TdWRKY proteins suggested that they are novel members of the WRKY family in durum wheat. TdWRKY1/2/4, TdWRKY3, and TdWRKY5 belong to the group Ia, IIa, and IIc, respectively. Enrichment of -regulatory elements related to stress responses in the promoters of some genes indicated their potential roles in mediating plant responses to a wide variety of environmental stresses. genes displayed different expression patterns in response to salt stress that distinguishes two durum wheat genotypes with contrasting salt stress tolerance phenotypes. genes tended to react earlier with a down-regulation in sensitive genotype leaves and with an up-regulation in tolerant genotype leaves. The transcripts levels in roots increased in tolerant genotype compared to sensitive genotype. The present results indicate that these genes might play some functional role in the salt tolerance in durum wheat.
WRKY转录因子参与植物生长、发育以及对生物胁迫的响应等多个方面。尽管已发现它们在调节植物对环境胁迫的响应中发挥作用，但这些作用仍有待探索，尤其是在农作物方面。硬粒小麦是世界上种植面积第二大的谷物。其基因组复杂、庞大且未测序，再加上缺乏基因组资源，阻碍了对其耐受机制的分子特征研究。本文描述了从硬粒小麦（. ssp.）中分离和鉴定五个基因的过程。利用基因保守区域内的引物对BAC基因组文库进行基于PCR的筛选，得到了五个BAC克隆。对这五个BAC进行全序列测序后，通过Triannot管道进行精细注释，结果显示整个序列的74.6%为转座元件，基因含量为3.2%，基因在转座元件的海洋中呈岛屿状排列。每个BAC克隆都含有一个基因。该研究表明，硬粒小麦中的TdWRKYs与其来自短柄草、大麦和. 的直系同源基因在基因组结构上具有非常广泛的保守性。TdWRKY蛋白的结构特征表明它们是硬粒小麦WRKY家族的新成员。TdWRKY1/2/4、TdWRKY3和TdWRKY5分别属于Ia、IIa和IIc组。一些基因启动子中与胁迫响应相关的调控元件的富集表明它们在介导植物对多种环境胁迫的响应中具有潜在作用。基因在响应盐胁迫时表现出不同的表达模式，这区分了两种具有不同盐胁迫耐受表型的硬粒小麦基因型。基因往往在敏感基因型叶片中较早出现下调反应，而在耐受基因型叶片中出现上调反应。与敏感基因型相比，耐受基因型根中的转录本水平增加。目前的结果表明，这些基因可能在硬粒小麦的耐盐性中发挥某些功能作用。
