Transcriptome analyses provide insights into the effect of temperature change on fiber quality of ramie

Seasonal temperature change contributes to differential fiber quality in bast fiber crops such as ramie, flax, etc. However, the knowledge of the regulatory role of temperature change in fiber development at the RNA level is limited. Here, we used transcriptome sequencing to explore how ambient temperature affects the quality of ramie fiber with different developmental degrees under simulated temperature conditions for different harvest seasons. We obtained 73 335 and 66 195 unigenes from two full-length transcriptomes, respectively. Based on comparative transcriptomics analysis, we identified a total of 14 228 differentially expressed genes, some of which are related to cell wall assembly or biogenesis, cell expansion, and cellulose synthesis, etc. We found that temperature change influenced fiber cell size and the synthesis of chemical constituents of the raw fiber and, specifically high temperature delayed the lignification of ramie bark and identified five MYB transcription factors closely related to the lignification process. Our findings provide a valuable resource for exploring the mechanism of fiber quality formation under temperature change and lay the foundation for genetic improvement of fiber quality.