Does High Temperature Affect Tomato Plants?

Tomatoes are a popular and important vegetable crop consumed worldwide, and they are grown in various climatic conditions. However, tomato plants are sensitive to temperature changes, particularly to high temperatures.

The Effects of High Temperature on Tomato Plants

At temperatures above 85°F (29°C), tomato plants can experience significant damage. High temperatures can adversely affect pollen viability, fruit development, yield, and fruit quality. When temperatures remain high for extended periods, the plants may produce misshapen and undersized fruits or none at all, causing significant economic losses to farmers.

High-temperature stress also affects the physiological and biochemical processes of tomato plants. It causes the accumulation of reactive oxygen species (ROS), which can lead to oxidative damage in plants. Excess ROS can affect various cellular components, including proteins, lipids, and nucleic acids, leading to cell damage and, in severe cases, cell death. Consequently, damaged cells can decrease fluid and nutrient uptake, resulting in wilted plants and reduced yields.

How Tomato Plants Cope with High Temperature Stress

Tomato plants have evolved several physiological and biochemical processes to cope with high-temperature stress. These mechanisms include heat shock proteins (HSPs), which are molecular chaperones that protect proteins from heat-induced denaturation. They also help in protein folding and refolding, promoting tolerance to high temperatures. Additionally, plants can activate antioxidative defense systems, such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), to neutralize ROS and reduce oxidative damage.

Furthermore, the production of abscisic acid (ABA) helps tomato plants regulate water loss and ion uptake to cope with high-temperature stress. ABA accumulates in plant tissue and affects genes responsible for stomatal closure, leading to the conservation of water and a reduction in transpiration. The closure of stomata reduces the uptake of ions, such as sodium and chloride, which can be toxic to plants when present in high concentrations.

Conclusion

Tomato plants are sensitive to high temperatures, which can lead to reduced yields, low fruit quality, and even crop failure. However, tomato plants have evolved several mechanisms to cope with high-temperature stress, including the production of HSPs, antioxidative defense systems, and ABA. Farmers can also adopt good agricultural practices, such as planting heat-tolerant tomato varieties, providing shade, irrigating during peak-temperature periods, and avoiding over-fertilization, to minimize the negative impacts of high-temperature stress on tomato production.