Lettuce and Basil Respond Differently to Light and Temperature, New Research Finds
ST. PAUL, MN – september 17, 2025 - A new study published today in Frontiers in Plant Science reveals stark differences in how cold-sensitive basil and cold-tolerant lettuce respond to varying combinations of blue light, far-red light, and temperature. The findings could have significant implications for optimizing indoor agriculture and understanding plant adaptation strategies in changing environments.
Researchers at Utah State University discovered that while increasing the proportion of far-red light boosted growth in both lettuce and basil, the interaction with temperature and blue light differed dramatically between the species. Lettuce shoot expansion was amplified by warmer temperatures but suppressed by higher levels of blue light, while basil’s internode elongation remained unaffected by either factor.These contrasting responses highlight the complex interplay of environmental signals in plant development and underscore the need for species-specific growing strategies.
the study, led by J. Shin, B. Bugbee, and E. Runkle, tested the effects of different lighting treatments and temperatures on lettuce and basil. Plants were grown under a consistent total light intensity (270 µmol m−2 s−1) and a 24-hour photoperiod,with variations in far-red light fractions (0.01, 0.19, or 0.32) and blue light levels (40 or 100 µmol m−2 s−1) at either 19 or 24°C. Results showed that increased far-red light significantly increased shoot expansion in lettuce and internode elongation in basil, as expected.
Interestingly, the research also found that increased shoot expansion in lettuce led to decreased foliage coloration, a change that was minimal in basil. This suggests differing mechanisms for coping with shade avoidance – a common plant response to competition for light. The researchers emphasize that these fundamentally different responses to light and temperature have implications for understanding shade-avoidant and shade-tolerant species.
“These findings demonstrate the complex integration of environmental signals in the regulation of growth,” the authors wrote. The study’s findings are particularly relevant as controlled environment agriculture, including vertical farms and greenhouses, becomes increasingly significant for food production. Understanding how different plant species respond to specific light and temperature combinations will be crucial for maximizing yields and optimizing resource use in these systems.
