by Plants, despite lacking conventional visual organs like eyes, have the remarkable ability to determine the origin of a light source. This information is crucial for plants to orient themselves and position their organs in a way that optimizes their exposure to sunlight. A recent groundbreaking study conducted by a team led by Prof. Christian Fankhauser at UNIL, in collaboration with colleagues at EPFL, has shed new light on this phenomenon.
Published in the journal Science, the study reveals that a light-sensitive tissue in plants utilizes the optical properties of the interface between air and water to create a visible light gradient. This gradient allows plants to perceive the direction of light and regulate their growth accordingly, a process known as phototropism.
Phototropism is a vital mechanism for plants as it enables them to capture more sunlight, which is then converted into chemical energy through photosynthesis. Photosynthesis is a critical process that fuels the production of food for both plants and animals.
While the photoreceptor responsible for initiating phototropism has been well-documented, the optical properties of photosensitive plant tissue have remained elusive. To unravel this mystery, a multidisciplinary team led by Prof. Fankhauser and Dr. Andreas Schüler from EPFL’s Solar Energy and Building Physics Laboratory embarked on a comprehensive investigation.
The study began with the observation of a mutant strain of Arabidopsis thaliana, a model plant species commonly known as thale cress. The mutant plants exhibited unusually transparent stems and failed to respond to light cues properly. Intrigued by this phenomenon, Prof. Fankhauser collaborated with Dr. Schüler to compare the optical properties of the mutant plants with those of wild-type specimens.
Their investigation revealed that the milky appearance of the stems in wild plants was caused by the presence of air in intercellular channels within the tissues. In contrast, the mutant plants had an aqueous liquid filling these channels, leading to a translucent appearance. The air-filled channels in the wild-type plants enabled the establishment of a light gradient that was detectable by the plants, allowing them to determine the direction of the light source.
This phenomenon arises due to the distinct refractive indices of air and water, which causes light scattering as it passes through the plant tissues. The researchers likened this to the phenomenon of a rainbow, which is also caused by light scattering.
The study not only unveils a novel mechanism by which plants perceive and respond to light but also provides insights into the formation and functions of air-filled intercellular channels. In addition to facilitating the formation of light gradients, these channels play crucial roles in gas exchange and helping plants withstand hypoxia in flooded conditions. However, their development and maintenance from the embryonic stage to adulthood remain poorly understood.
The genetic resources utilized in this study hold promise for furthering our understanding of the formation and regulation of these intriguing structures. By deciphering the intricate ways in which plants interact with light and their environment, this research opens up new possibilities for harnessing the potential of plants in various applications, including agriculture, horticulture, and biotechnology.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
Money Singh is a seasoned content writer with over four years of experience in the market research sector. Her expertise spans various industries, including food and beverages, biotechnology, chemical and materials, defense and aerospace, consumer goods, etc.
