Plant Metabolism: A research team has reviewed the detrimental effects of high nighttime temperatures (HNT) on temperate plant species, highlighting disruptions in physiological and metabolic processes such as carbohydrate, amino acid, and hormone metabolism. HNT accelerates leaf senescence, disrupts cellular membranes, and increases respiration rates, leading to the loss of carbon and carbon deficits within plant tissues. This review emphasizes the need for further research to uncover the key metabolic pathways and molecular mechanisms involved in plant adaptation to HNT, aiming to inform genetic modifications, breeding strategies, and improved management practices to enhance plant resilience.
Global warming, particularly the faster rise in nighttime temperatures compared to daytime temperatures, adversely affects plant growth and development. Current research shows that elevated HNT hinder plant productivity, with significant yield losses observed in crops like rice and wheat. However, the mechanisms behind these inhibitory effects, particularly regarding physiological and metabolic processes, are not well understood.
A published in Grass Research on 04 July 2024, highlights the need to investigate how HNT affects carbon, amino acid, and hormone metabolism to develop strategies for mitigating its adverse impacts on plant productivity.
Researchers review the current state of research, revealing that high HNT disrupts critical physiological processes, including photosynthesis and respiration, which control carbon balance and availability. HNT accelerates leaf senescence, reduces chlorophyll content, and damages chloroplasts, leading to a significant decline in photosynthetic efficiency. Enhanced respiration rates at night consume more carbohydrates, exacerbating carbon deficits and reducing overall plant productivity. Additionally, HNT impacts amino acid metabolism, causing a variable response among different amino acids, and increases the production of reactive oxygen species (ROS), leading to oxidative damage of Rubisco. Hormone metabolism is also affected by HNT, with a decrease in growth-promoting hormones like cytokinins and auxins, and an increase in stress-related hormones such as abscisic acid (ABA) and salicylic acid (SA). This review highlights the urgent need for further investigation into how plants adapt to HNT, aiming to develop genetic modifications, breeding strategies, and improved management practices to enhance plant resilience and productivity in the face of rising nighttime temperatures.
According to the study's lead researcher, Bingru Huang, “The mechanisms of how plants can adapt to this stress remain largely unknown, particularly the key metabolic pathways and molecular factors or networks. Further research addressing these unknown aspects is critically important for improving plant resilience against warmer nights, particularly through genetic modification and breeding efforts, as well as management practices.”
In summary, nighttime temperatures are rising faster than daytime temperatures, adversely affecting temperate plant species by disrupting photosynthesis, accelerating leaf senescence, and increasing respiration rates, leading to carbon deficits. HNT also alters amino acid and hormone metabolism, with stress-related hormones increasing and growth-promoting hormones decreasing. Understanding the precise metabolic pathways and molecular mechanisms of plant adaptation to HNT is crucial. Future research should focus on developing genetic modifications, breeding strategies, and management practices to enhance plant resilience to warmer nights. Newswise/SP