Identification, Characterization and Expression of Two Transcription Factors MYB44 and WRKY22 from Drought Tolerant Peanut Cultivar L14

Peanut is an important food crop that provides vegetable oil and protein to the global agricultural economy. However, its productivity is significantly impacted by environmental stresses, particularly drought. A recent study has identified and cloned two transcription factors, AhL14_MYB44 and AhL14_WRKY22, associated with various abiotic stresses. In silico analysis revealed that AhL14_MYB44 had two DNA-binding domains, while AhL14_WRKY22 had a DNA-binding domain involved in regulating plant defense responses. Both proteins were localized in the nucleus, and no transmembrane domains or signal peptides were detected. The study identified that MYB44 and WRKY22 were located on peanut chromosomes 08, 17 and 3, 13, respectively. Further analysis showed that these factors interacted with various abiotic stress-related genes. The DNA-binding domains were modeled, and the docking analysis indicated that both proteins had a high probability of binding to the promoters for regulating drought stress-related genes, such as LEA1 and RD29A. The study conducted in silico analysis and RT-PCR to investigate the expression levels of MYB44 and WRKY22 genes in different organs of peanuts. Their expression was upregulated in root tissues under mannitol stress compared to the control. The study suggests that MYB44 and WRKY22 may play critical roles in the peanut's response to drought stress, in addition to their other functions, and could offer potential applications in crop improvement strategies aimed at developing transgenic drought-tolerant peanut cultivars.