Differential gene expression in chronically irradiated herbaceous species from the Chernobyl exclusion zone

Transcriptional activity of genes related to ionizing radiation responses in chronically irradiated plant populations at radioactively contaminated territories can be a cost-effective and precise approach for stress response evaluation. However, there are limits to studying non-model plants in field conditions. The work studies the transcriptional activity of candidate genes of adaptation to chronic radiation exposure in plant populations from radioactively contaminated territories of the Chernobyl. In this work, we studied plant species with different sensitivity to acute irradiation: <i>Trifolium repens</i> L., <i>Taraxacum officinale</i> Wigg., and <i>Dactylis glomerata</i> L., sampled in the Chernobyl exclusion zone. The differential expression of several candidate genes of adaptation to chronic radiation exposure in the leaves of these species was analyzed, including homologs of <i>Arabidopsis thaliana</i> genes <i>SLAC1</i>, <i>APX1</i>, <i>GPX2</i>, <i>CAB1</i>, <i>NTRB</i>, <i>PP2-B11</i>, <i>RBOH-F</i>, <i>HY5</i>, <i>SnRK2.4</i>, <i>PDS1</i>, <i>CIPK20</i>, <i>SIP1</i>, <i>PIP1</i>, <i>TIP1</i>. All studied species were characterized by upregulation of the <i>CAB1</i> homolog, encoding chlorophyll <i>a</i>/<i>b</i> binding protein, at radioactively contaminated plots. An increase in the expression of genes associated with water and hydrogen peroxide transport, intensity of photosynthesis, and stress responses (homolog of aquaporin <i>TIP1</i> for <i>T. repens</i>; homologs of aquaporin <i>PIP1</i> and transcription factor <i>HY5</i> for <i>D. glomerata</i>; homolog of CBL-interacting serine/threonine protein kinase <i>CIPK20</i> for <i>T</i>. <i>officinale</i>) was revealed. The methodological approach for studying gene expression in non-model plant species is described, which may allow large-scale screening studies of candidate genes in various plant species abundant in radioactively contaminated areas.