Thermosensing Plants

As temperature increases due to global warming, plants with high heat tolerance and high crop productivity have started to become favorable in agriculture. Temperature is a huge factor in the survival, growth and conditions of all life on Earth. Leading to the effects of heat stress and how heat stress tolerance in life forms, especially plants, becoming crucial to understand. 

Plants have evolved mechanisms that change their metabolism as an effect of an increase in temperature. These adaptations at suboptimal high temperatures are known as “thermomorphogenesis.” Thermomorphogenesis is a version of thermal acclimation that helps plants when in high stress. When plants are exposed to extreme temperatures and high heat stress, this leads to cellular damage and can even result in plant death. In addition, the ability for a plant to tolerate high stress is known as ‘basal thermotolerance’.

Plants contain response pathways that are responsible and get activated as an effect of increase in temperature. For example, in Arabidopsis (model plant), warm temperatures led to longer hypocotyl, petioles, slimmer leaves and early flowering.  These responses led the plant to acclimatize to the change in temperature. Moreover, when the temperature rise leads to high stress, plants respond by activating their Heat Stress Response (HSR) pathway, which triggers stress response genes. During the activation of HSR, plants will gather heat shock proteins that stop protein aggregation and help the refolding of damaged proteins from heat stress. The heat shock proteins are controlled by heat stress transcription factors, and the actions of the heat stress proteins play an important and vital role in thermotolerance. 

Plants sense change in temperature and convert it into intracellular signaling response through four major thermosensors. These thermosensors include: plasma membrane channel, histone sensor, and two unfolded protein sensors.) Additionally, there have been reports of the existence of additional thermosensors inside the cell. 

To encapsulate, currently, Earth is going through extreme changes in temperatures and is expected to rise 1.5 degrees celsius in the next two decades. Global warming has had a humongous impact on plants growth, distribution, survival and crop yield. Through all this, plants have been able to develop different thermosensors in response to the dramatic rise in temperature. Understanding these mechanisms are important for scientists to aid these plants, and is vital knowledge in this present time. 

References:

Samtani, Harsha, et al. “Thermosensing in Plants: Deciphering the Mechanisms Involved in Heat Sensing and Their Role in Thermoresponse and Thermotolerance.” Environmental and Experimental Botany, vol. 203, 1 Nov. 2022, pp. 105041–105041, https://doi.org/10.1016/j.envexpbot.2022.105041. Accessed 11 Jan. 2024.

Wu, Junwen, et al. “Thermosensing and Thermal Responses in Plants.” Trends in Biochemical Sciences, vol. 48, no. 11, 30 Aug. 2023, pp. 923–926, www.cell.com/trends/biochemical-sciences/abstract/S0968-0004(23)00205-0?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0968000423002050%3Fshowall%3Dtrue, https://doi.org/10.1016/j.tibs.2023.08.002. Accessed 10 Feb. 2025.