Transcriptional analysis of lentil (Lens culinaris Medik.) plant exposed to drought stress by RNA sequencing method

Drought stress is one of the main environmental factors affecting the growth and productivity of the cultivated crops, including lentils. In this thesis, we aimed to obtain information about genome wide transcriptional regulation of Lens culinaris Medik. cv. Sultan roots and leaves in short and long term drought conditions. After drought stress conditions for lentil were generated by measuring biochemical and physiological parameters, samples were subjected to de novo RNA sequencing-based transcriptome analysis. Analysis of differentially expressed genes (DEGs) on these transcripts has shown that the duration of drought stress has a greater effect on the transcriptional regulation at the lentil root. While the number of DEGs under short-term drought stress was 2.915, in the long-term drought stress of the root, the number of DEGs increased to 18.327. Furthermore, the Gene Ontology analysis revealed that biological processes such as protein phosphorylation, signal transduction, transcription regulation, DNA replication, and preservation of root meristem identity were arranged differently in response to long-term drought stress. In addition, DEGs that play a role in circadian rhythm and photoreceptions show that drought stress has a negative impact on internal oscillators that may have detrimental consequences on plant growth and survival. In conclusion, this study revealed a detailed comparative transcriptome response in the roots and leaves of lentil plants in short and long-term drought conditions. Our findings suggest that not only the regulation of the genes in the leaves is important, but also the genes regulated in the roots are important in terms of drought stress and it should be considered for the improvement of lentil plant against drought tolerance