Background Global warming has significant impacts on crop growth and agricultural stability, particularly for temperature-sensitive crops such as radish (Raphanus sativus). Elucidating mechanisms underlying heat-stress tolerance is essential for developing high-temperature tolerant radish cultivars. Objective This study aimed to identify heat-tolerant and heat-sensitive radish cultivars and to analyze the mechanisms of heat-stress resistance through integrated analyses of gene expression patterns and protein interaction networks. Methods In this study, we screened 17 radish cultivars after high-temperature treatment in a growth chamber and validated their contrasting high-temperature tolerance under open-field conditions. To identify specific genes involved in heat stress as upstream signaling components in heat-tolerant cultivars, the expression of 26 receptor-like cytoplasmic kinases (RLCKs) of Arabidopsis thaliana under high-temperature conditions (37 °C for 2h) was analyzed. We also analyzed downstream components that could be involved in heat-stress tolerance using quantitative real-time PCR. Protein–protein interaction networks were investigated using yeast two-hybrid analysis, with Rs032070 and RsPP7 used as bait proteins. Results After high-temperature treatment of 17 diverse radish cultivars, differences in heat-stress tolerance were investigated, and three heat-tolerant cultivars and three heat-sensitive cultivars were selected. Among radish RLCKs, the expression of Rs275520, Rs355490, and Rs032070 was significantly changed at 37 °C compared with the normal temperature (23 °C), whereas Rs497590 showed a slight down-regulation. Using Rs032070 as bait, eight interacting proteins were identified with the yeast two-hybrid system, and the expression of all eight genes was induced by high-temperature treatment. Notably, the expression of Ser/Thr protein phosphatase 7 (PP7, Rs499360) was up-regulated in heat-tolerant cultivars after 37 °C treatment, whereas no such change was detected in heat-sensitive cultivars. Using PP7 as bait, four different interacting proteins were identified, and the transcript levels of these four genes were significantly up-regulated after high-temperature treatment. Conclusion Overall, our results highlight the Rs032070-RsPP7-centered network as a key signaling hub for radish high-temperature responses and a potential target for developing heat-tolerant cultivars. These results are helpful for understanding heat-stress-related mechanisms in radish under climate warming.

Selection of heat stress-tolerant cultivars from radish and analysis of gene expression under high-temperature

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发表日期：

2026年4月27日

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Jae-Han Choi,
Won Byoung Chae,
Man-Ho Oh

摘要

Background

Global warming has significant impacts on crop growth and agricultural stability, particularly for temperature-sensitive crops such as radish (Raphanus sativus). Elucidating mechanisms underlying heat-stress tolerance is essential for developing high-temperature tolerant radish cultivars.

Objective

This study aimed to identify heat-tolerant and heat-sensitive radish cultivars and to analyze the mechanisms of heat-stress resistance through integrated analyses of gene expression patterns and protein interaction networks.

Methods

In this study, we screened 17 radish cultivars after high-temperature treatment in a growth chamber and validated their contrasting high-temperature tolerance under open-field conditions. To identify specific genes involved in heat stress as upstream signaling components in heat-tolerant cultivars, the expression of 26 receptor-like cytoplasmic kinases (RLCKs) of Arabidopsis thaliana under high-temperature conditions (37 °C for 2h) was analyzed. We also analyzed downstream components that could be involved in heat-stress tolerance using quantitative real-time PCR. Protein–protein interaction networks were investigated using yeast two-hybrid analysis, with Rs032070 and RsPP7 used as bait proteins.

Results

After high-temperature treatment of 17 diverse radish cultivars, differences in heat-stress tolerance were investigated, and three heat-tolerant cultivars and three heat-sensitive cultivars were selected. Among radish RLCKs, the expression of Rs275520, Rs355490, and Rs032070 was significantly changed at 37 °C compared with the normal temperature (23 °C), whereas Rs497590 showed a slight down-regulation. Using Rs032070 as bait, eight interacting proteins were identified with the yeast two-hybrid system, and the expression of all eight genes was induced by high-temperature treatment. Notably, the expression of Ser/Thr protein phosphatase 7 (PP7, Rs499360) was up-regulated in heat-tolerant cultivars after 37 °C treatment, whereas no such change was detected in heat-sensitive cultivars. Using PP7 as bait, four different interacting proteins were identified, and the transcript levels of these four genes were significantly up-regulated after high-temperature treatment.

Conclusion

Overall, our results highlight the Rs032070-RsPP7-centered network as a key signaling hub for radish high-temperature responses and a potential target for developing heat-tolerant cultivars. These results are helpful for understanding heat-stress-related mechanisms in radish under climate warming.