Hot conditions cause stress to crops, leading to decreased yield. Heat and low moisture cause a decrease in nutrient uptake, plant growth, and overall yield. Heat also causes a decrease in the plant’s crucial hormone, cytokinin. Cytokinin starts to decrease in small grains at 67°F and 87°F in other crops.
What is Cytokinin?
Cytokinins have been extensively studied through the years (Osugi & Sakakibara, 2015). Cytokinin is considered the dispatcher hormone, and it’s responsible for several plant functions, including growth, development, and stress response. This hormone is produced in root tip meristematic tissue, and it stimulates shoot and branching formation and plays an important role in reducing senescence (Kieber & Schaller, 2014, Osugi & Sakakibara, 2015).
Cytokinin and high temperatures
Heat stress can cause a decrease in endogenous cytokinin levels, leading to a reduction in plant growth and productivity (Liu, et al., 2020), leading to a negative impact on various plant growth and developmental processes, such as cell division, growth, and development (Cheikh & Jones, 1994, Cortleven et al., 2019). Cytokinin is sensitive to high temperatures, and its breakdown can occur in plants under such conditions. When exposed to high temperatures (for short or long periods) cytokinin is reduced, leading to a significant reduction in the functions that cytokinin controls.
Adding synthetic cytokinin can help mitigate the negative effects of high temperatures on plant growth and metabolism. By adding synthetic cytokinin, plant growth can be stimulated, and the negative effects of heat stress can be reduced (Cheikh & Jones, 1994, Liu et al., 2020). Therefore, there is evidence that cytokinin is involved in heat stress reduction (Liu et al., 2020).