Houston Daily

University of Houston engineers have found that melatonin, a hormone commonly used as a sleep aid by people, plays a different role in plants by promoting their growth and helping them manage stress. The research, led by assistant professor Abdul Latif Khan and graduate student Imad Aijaz, was published in iScience.

Melatonin is widely used in the United States to help regulate sleep cycles. About 27% of U.S. adults use melatonin supplements to help control their internal clocks. In plants, however, melatonin influences various biological processes through circadian regulation. "In plants, the internal clock can adjust the phase of various biological processes, such as gene expression, metabolic regulation and protein stability, to coincide with daily and/or seasonal cycles," said Aijaz. He added that this regulation enhances photosynthesis and growth rates and may impact crop flowering, seed yield, and how plants respond to stresses.

Plants produce their own melatonin naturally. They also benefit from microbes living near their roots that generate additional melatonin. "Melatonin-producing microbes can enrich soils, enhancing melatonin availability, uptake, and transport within plants to improve stress tolerance and growth,” Khan explained. The article reviews current knowledge about how melatonin is produced in both plants and microbes and discusses its ecological roles.

The research suggests using melatonin-based strategies for sustainable crop management. Scientists are exploring genetically engineered strains of melatonin to protect crops from disease, drought, and toxins.

Khan emphasized the need for further research beyond traditional agricultural crops: “So far, most work has focused on species that are important for agriculture or health, but we know very little about how melatonin works in wild plants or those with cultural value. Studying these overlooked plants could help us understand how melatonin helps them survive harsh environments or adapt to changes in nature.”