One Heat Shock Transcription Factor Confers High Thermal Tolerance in Clematis Plants.

Clematis plants play an important role in botanical gardens. Heat stress can destroy the activity, state and conformation of plant proteins, and its regulatory pathway has been well characterized in and some crop plants. However, the heat resistance response mechanism in horticultural plants including has rarely been reported. Here, we identified a heat-tolerant clematis species, . The relative water loss and electrolytic leakage were significantly lower under heat treatment in compared to Stolwijk Gold. Differential expression heat-tolerant genes (HTGs) were identified based on nonparametric transcriptome analysis. For validation, one heat shock transcription factor, , extremely induced by heat stimuli in , was identified to confer tolerance to heat stress in and . Furthermore, silencing of by virus-induced gene silencing (VIGS) led to heat sensitivity in tobacco and , suggesting that the candidate heat-resistant genes identified in this RNA-seq analysis are credible and offer significant utility. We also found that improved heat tolerance of by elevating heat shock protein (HSP) expression, which was negatively regulated by . Taken together, this study provides insights into the mechanism of heat tolerance and the findings can be potentially applied in horticultural plants to improve economic efficiency through genetic approaches.