Gene Expression of Zygophyllum sp. under Heat Stress Using cDNA-SCoT

Plants adapt to environmental stresses such as high salinity, drought, and extreme temperatures through complex biochemical and physiological mechanisms involving hormones, receptors, protein kinases, transcription factors, and regulatory proteins. This study used protein profiling and molecular markers to investigate the genetic diversity and heat stress response in Zygophyllum populations from Saudi Arabian habitats. Proteins were extracted from 10-day-old seedlings, genomic RNA was isolated, catalase isozyme activity was assessed, and genetic diversity was analyzed using Start Codon Targeted (SCoT) markers. The catalase isozyme (CAT1) exhibited varying intensities, indicating its role in heat adaptation. Protein profiling revealed temperature-dependent changes, including the emergence of novel bands under heat stress. SCoT analysis generated 113 amplicons with a polymorphism rate of 75.2%, and genetic similarity among populations ranged from 0.71 to 0.84, forming distinct clustering patterns. A unique heat-responsive fragment (474 bp) was identified, sequenced, and classified as vacuolar-sorting receptor 1 isoform (accession number PQ569837). The identification of this heat-responsive vacuolar-sorting receptor 1 isoform enhances our understanding of heat tolerance mechanisms in desert plants and highlights the genetic diversity within Zygophyllum populations. These findings demonstrate that Zygophyllum exhibits significant genetic and biochemical adaptations to heat stress, offering valuable insights into plant resilience in extreme environments.