Transcriptomic Insights Into Elevation-Dependent Gene Expression in Rhododendron anthopogon D.Don: Implications for...

Understanding the molecular basis of how species adapt to varying elevations can advance our knowledge regarding forecasting and regulating the consequences of climate change on plants. Here, we investigate the variation in gene expression patterns of Rhododendron anthopogon D.Don along an elevation gradient (3200-3900 m) in Kashmir Himalaya, India, based on comparative transcriptomics. We observe the highest number of differentially expressed transcripts between the lowest (3200 m) and highest (3900 m) sites, indicating a strong elevation-associated divergence in gene activities. Most of these transcripts were significantly enriched in biological processes linked to stress response and secondary metabolism, suggesting their role in the elevation-dependent adaptation of R. anthopogon. We identified different genes for secondary metabolite production; the expression pattern of these genes increased with the rise in altitude. By using gene co-expression network (GCN) analysis to elucidate the interaction between targeted genes and regulators, we found that 200 transcription factors belonging to 36 families were putatively involved in regulating important metabolic pathways of R. anthopogon in response to changing altitudes. Thus, these metabolic pathways may play an important role in the adaptation of R. anthopogon in response to environmental stress along an elevation gradient. Therefore, the findings of this study will provide insights into how alpine R. anthopogon adapts to environmental responses to global climate change.