Discovering the Dual Function of Plant Molecules in Monitoring Night-time Temperatures
A Researchers from the University of Oxford, alongside an international cohort of scientists, have unveiled that plants have an in-built 'thermometer' molecule that helps them gauge the temperatures of nighttime. Intriguingly, these molecules, known as phototropins, which are predominantly perceived to sense daylight, have been found to transition their role once the sun sets, behaving as cellular temperature sensors. This fresh revelation could play a significant role in evolving crops that are fortified against potential temperature variations, owing to climatic shifts.
B The groundbreaking study, disseminated in the journal Nature, delineates how phototropins alter their state at night. Drawing parallels to the mercury inside thermometers, scientists emphasize that the rate of this molecular shift directly corresponds to the ambient temperature, and this subsequently governs the plant's growth trajectory.
C For millennia, those tending to plants, be they gardeners or farmers, have been cognizant of the profound influence of temperatures on plant growth dynamics. A mild winter, for instance, often leads to premature budding in numerous plants, a phenomenon that has traditionally been utilized to foretell ensuing climatic conditions and optimize harvest timings. This novel research, however, is pivotal in demystifying the exact molecular process within plants that is sensitive to temperature fluctuations.
D As the repercussions of climate change become palpably erratic and profound, this discovery could be a beacon of hope. Dr. Sarah Kendal, spearheading the research from Oxford’s Green Plant Laboratory, accentuates, “By 2075, it's projected that global agricultural output needs to augment by 70% to sustain our population. But, with escalating temperatures becoming a norm, primary staples like maize and barley are under jeopardy. Every degree increase in temperature can potentially slash yields by nearly 9%. Unveiling molecules in plants that can sense and respond to temperature shifts could be instrumental in devising crops that can endure temperature-induced stresses and adapt to the changing climate.”
E During the daytime, when phototropins are active, they bind with the DNA, curbing plant growth. The presence of sunlight maintains this active state, inhibiting growth. Conversely, when in the shadow, these molecules become rapidly inactive, prompting the plant to expedite its growth to seek sunlight, a crucial mechanism for plants vying to outgrow neighboring vegetation. “This light-triggered alteration in phototropins ensues almost instantaneously, in mere milliseconds,” elucidates Dr. Kendal.
But, come nightfall, the story unfolds differently. Post-sunset, these molecules don't swiftly become inactive. Instead, they experience a gradual transition known as 'nocturnal shift’. Dr. Kendal explains, “Mirroring how mercury responds in a thermometer, the pace at which phototropins undergo this nocturnal shift is emblematic of the temperature. Cold environments decelerate this transition, keeping the molecules largely active, which explains the stunted growth in winter. Conversely, warmth accelerates this shift, rendering phototropins inactive quickly, thus facilitating plant growth.”
F Different plant species have varied seasonal indicators. Tulips, for instance, are extremely receptive to temperature, and during a balmy winter can bloom weeks ahead of schedule. This research clarifies why the age-old adage, “pine before spruce, expect some juice; spruce before pine, all will be fine,” holds water. Dr. Kendal sheds light on this, “Pine trees are predominantly temperature-driven, possibly employing phototropins as thermal sensors. Spruce trees, on the other hand, are more attuned to day length. Therefore, a warmer spring typically witnesses pine trees blossoming before spruce, hinting at a possibly warm summer.”
G This groundbreaking revelation is a culmination of over a decade of meticulous research, incorporating expertise from Japan, Brazil, the UK, and the USA. The experiments were primarily conducted using a model system involving the garden cress plant, Lepidium sativum. However, Dr. Kendal is optimistic about the application of these findings, “The genes linked to temperature sensing through phototropins are also prevalent in essential crops. With the surge in genetic engineering capabilities, it's plausible for scientists to swiftly detect and even fine-tune these genes in crops, bolstering their resilience and adaptability.”
