Relationship between growth and gene expression in papaya treated with freeze-thaw awakening method

The freeze-thaw awakening is a method in which seeds or germ cells prior to germination are slowly cooled, stored, and thawed to promote growth. To further test the validity of this method, we applied freeze-thaw awakening treatment on papaya seeds. When the seed was grown under room temperature (15-25C), the germination rate increased by more than 40% compared to those that were not subjected to the method. At 60 days post germination, the plant’s height was about 1.4 times as high as that of the untreated control. In addition, when both samples were grown in the field for about a year and a half, the treated showed darker green leaf color and an increase of seedlings per seed compared to the control. No significant difference in weight per fruit was observed. Comprehensive gene expression analysis of papaya leaves using RNA-seq showed more than 1000 differentially expressed genes, of which had genes involved in plant hormone synthase and environmental stress response. From these results, we show here that freeze-thaw-awakening is an effective method in promoting papaya growth. Total RNA-seq data was performed between Freeze-thaw-awakening method-treated and untreated (control) Carica Papaya Linn leaves (n=1).