By integrating hormonal profiling, transcriptome sequencing, and gene network analysis, the team identified major regulatory differences shaping heat response. Cassava showed more controlled hormone adjustments and maintained photosynthesis, while potato activated large-scale stress-response pathways. The findings offer key gene resources to guide breeding of climate-resilient crops.
Cassava thrives in hot regions and grows optimally at 27–35°C, while potato performs best at 18–22°C and suffers severe inhibition above 25°C. Although cassava’s heat-tolerance is well recognized, its molecular basis remained unclear. Heat response in plants involves hormone signaling, transcription regulation, and heat shock protein activity. Previous research highlighted roles of auxin, salicylic acid, ABA, and heat shock factors in thermotolerance. However, knowledge of cassava's transcriptomic and hormonal dynamics under prolonged heat conditions was limited. Conversely, potato heat-tolerant behavior has been linked to antioxidant ability and photosynthetic stability. Extreme heat events driven by global climate change threaten crop productivity worldwide, making heat-tolerant varieties critical for food security. Understanding why these crops differ in resilience can inform breeding strategies for climate-ready agriculture.
A study (DOI: 10.48130/tp-0025-0031) published in Tropical Plants on 10 November 2025 by Wenquan Wang’s & Xin Guo’s team, Hainan University, reveals the molecular basis underlying cassava’s superior heat tolerance compared to potato, providing gene resources for breeding climate-resilient crops.
To compare heat-stress responses in cassava and potato, researchers conducted multi-level analyses integrating physiological observation, hormone profiling, RNA-seq transcriptome sequencing, transcription factor prediction, hormone biosynthesis pathway comparison, weighted gene co-expression network analysis (WGCNA), and RT-qPCR validation. Tissue-cultured and potted seedlings were first subjected to high-temperature treatment to assess visible stress phenotypes, followed by thermal imaging to monitor leaf temperature changes. Hormonal content was quantified to evaluate metabolic responses, and 72 transcriptome libraries (36 cassava and 36 potato samples) were generated for differential expression analysis, with functional enrichment performed to identify heat-responsive pathways. Subsequently, transcription factor families and hormone biosynthesis-related genes were annotated, while WGCNA was applied to construct regulatory modules, and a subset of key genes was validated using RT-qPCR. Corresponding results showed that cassava cultivar KU50 maintained stronger heat tolerance than SC205, while potato cultivar FAVORITA performed better than Qingshu No.9, yet overall potato exhibited more severe heat injury including wilting. Cassava leaves showed increased surface temperature and slight yellowing, whereas potato suffered dehydration. Hormone profiling revealed that cassava increased ACC (up to 4.5-fold) with moderate ABA and BR reductions, while potato displayed sharp declines in ACC and ABA with no detectable BR. RNA-seq identified 27,701 cassava genes and 26,714 potato genes, where cassava thermosensitive varieties exhibited more DEGs than tolerant ones, opposite to potato. Functional enrichment linked cassava to protein folding and photosynthetic electron transport regulation, while potato DEGs were dominated by antioxidant detoxification and photosynthesis impairment. TF prediction showed different dominant families, and hormone pathway analysis revealed more up-regulated ACS and NCED genes in cassava. WGCNA further showed cassava modules enhancing photosynthesis and controlled HSP expression, while potato relied on ROS scavenging. RT-qPCR confirmed transcriptomic accuracy with R²>0.90.
This research demonstrates that cassava withstands heat by maintaining photosynthesis and hormonal balance, while potato relies on energy-costly stress repair responses. The identified hub genes, including ACS and NCED in hormone biosynthesis, and HSF-HSP networks in both crops, provide valuable targets for engineering thermotolerance. Breeding programs could introduce cassava-like regulatory traits into temperate crops to stabilize yields under heat waves. The findings also highlight specific modules responsible for heat resilience, supporting development of molecular markers, gene editing strategies, and climate-adaptive cultivar improvement.
###
References
DOI
10.48130/tp-0025-0031
Original Source URL
https://doi.org/10.48130/tp-0025-0031
Funding information
This study was supported by the Hainan Provincial Natural Science Foundation (Grant No. 324MS122), the National Natural Science Foundation of China (Grant No. 32360458), and the Startup Funds for the Double First-Class Disciplines of Crop Science at Hainan University (Grant No. RZ2100003362), all of which contributed to the successful completion of this research.
About Tropical Plants
Tropical Plants (e-ISSN 2833-9851) is the official journal of Hainan University and published by Maximum Academic Press. Tropical Plants undergoes rigorous peer review and is published in open-access format to enable swift dissemination of research findings, facilitate exchange of academic knowledge and encourage academic discourse on innovative technologies and issues emerging in tropical plant research.