Author: Katso Lethola
Lethola, Katso, 2019 Transcriptional repressor gene, TaDr1: Expression analysis under drought conditions in bread wheat from different countries , Flinders University, College of Medicine and Public Health
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Wheat is one crucial staple cereal crop of great significance to the human population. It has, and continues to, contribute to the livelihoods of many human beings including benefits of their economy and culture. Wheat production is threatened by drought stress. The impact of drought stress in wheat production calls for development of drought tolerant genotypes. Breeding for drought tolerance is a challenging process as its genetic control is complex and is influenced by environmental conditions. Researchers have identified some of the genes which can be influenced by environmental conditions and involved in the regulation of gene expression which are called Transcription factors. Among other transcription regulators, one regulatory protein encoded by the TaDr1 gene has been reported to be upregulated under drought conditions. Dr1 is a transcriptional repressor and couples with DrAp1 to execute repressive transcriptional activity. In this study, the expression of TaDr1 under different levels of drought stress was evaluated and compared across six wheat accessions originating from different countries. Results indicated that VK-1 from Kazakhstan was more drought tolerant and SST-398 was more drought sensitive compared to other accessions under greenhouse conditions. However, the trends of drought tolerance in wheat accessions from Australia under conditions were slightly different from field trails results observed by seed providers but both greenhouse and field trails findings were similar in Kazakhstan and South- African accessions. Further analysis of expression profile revealed that two homeologs of TaDr1 were upregulated under drought conditions in most of the accessions. Moreover, results suggested that TaDr1a had strong influenced on TaDr1 consensus expression profiles. This indicates differences between greenhouse and field trials experiments. It was concluded that TaDr1 was drought responsive and strongly genotype-dependent which confirmed by other researchers.
Keywords: Wheat,Drought stress,gene expression, Down-regulator Transcription 1 (Dr1),transcriptional repressor,homeologs,DrAp1,Drought conditions
Subject: Biotechnology thesis
Thesis type: Masters
Completed: 2019
School: College of Medicine and Public Health
Supervisor: Associate Professor Peter Anderson