Recently, Professor Teng Nianjun's team from the College of Horticulture at Nanjing Agricultural University published a research paper online in Plant Physiology, revealing the molecular mechanism by which two transcription factors LlHOX6 and LlHB16 competitively bind to gene promoters to regulate heat tolerance in lily.

 

The study found that LlHOX6 and LlHB16 can bind to the promoters of heat tolerance related genes LlHSFA2 and LlMBF1c and inhibit their expression. LlHB16 can self-activate expression to form a positive feedback loop, while LlHOX6 inhibits LlHB16 expression. The two can form polymer interactions with each other. LlHOX6/LlHB16 heteropolymers compete with LlHB16 homopolymers in activating target gene expression.

 

In summary, by inhibiting the transcriptional activation function of LlHB16, LlHOX6 weakens the heat stress response and heat tolerance of lily. This discovery reveals a new regulatory mechanism of heat tolerance in plants and provides new ideas for molecular breeding to improve heat tolerance in lily.