MOLECULAR CHARACTERIZATION OF STRESS-RESPONSIVE SIGNALING CASCADES IN PLANTS

Abstract

Abiotic stresses are ever-present and include drought, salinity, and extreme temperatures, among others, and impact the growth, development and productivity of plants negatively. Plants have adapted more complex stress-responsive signaling networks to cope with such challenges, which control molecular and physiological adaptations. Nevertheless, the exact processes of integration and control of these signaling cascades are not yet fully understood. The overall purpose of the present study was to molecularly characterize the main stress-responsive signaling pathways in plants, including the identification of essential genes and regulatory elements in the process of signal transduction in response to the stressful conditions. In order to do this, abiotic stress treatments were introduced to plants under controlled conditions and thorough molecular analyses carried out. Quantitative real-time PCR (qRT-PCR) and transcriptomic analysis were used to measure gene expression, the changes in protein levels were analyzed by Western blotting and kinase activity measurements. Analysis of sequence data, prediction of functional domains, and creation of signaling networks were analyzed using bioinformatics tools. The findings showed strong differences in gene expression of stress responsive genes, namely, transcription factors and signaling proteins that were MAPK cascade and reactive oxygen species (ROS) related. The fact that certain signaling modules were more actively activated under stress conditions also suggested that they were key intermediates in mediating adaptive responses. Also, analysis of interaction revealed that several signaling pathways may have cross-talk. Overall, this paper offers useful information about the molecular structure of stress-sensing signaling pathways in plants. These discoveries can be used to understand the mechanisms of plant stress tolerance better, and can be used in the future to create stress-resistant crop varieties by using molecular breeding approaches.