Comparative physiology and transcriptome analysis reveals the regulatory mechanism of genome duplication enhancing cold resistance in Fragaria nilgerrensis

We synthesized autotetraploid strawberry (2n = 4x = 28) was from wild strawberry (Fragaria nilgerrensis; 2n = 2x = 14) by using a primary meristem processing technique. Then physiochemical and transcriptomic analyses were conducted to determine the underlying molecular mechanism of chromosome doubling in response to cold resistance. Transcriptome analysis revealed that many cold stress responsive genes and pathways were differentially triggered and enriched in the autotetraploids including Ca2+ signal transduction, transcription factor (TF) activity, reactive oxygen species (ROS) scavenging system, abscisic acid (ABA) regulation, alterations in lipid composition and the accumulation of osmoprotectants. These modifications enhanced the antioxidant defense system and protected the integrity of membranes and cellular organelles, which contribute to enhancing cold resistance of autotetraploids.