The Leaf Shape Mechanism Discovery, decodes the diversity in leaf shapes, revealing nature’s mechanism of creating diverse leaf patterns.
Every day we see various kinds of leaves having diverse leaf shapes and patterns. Thinking of how each type of plant has a particular leaf shape and design has kept us wondering.
This research study reveals the leaf shape mechanism of all plants. A carnivorous plant known as Utricularia gibba (bladderwort) was used in this study. Utricularia gibba plant has evolved an unusual leaf shape. The leaves of this plant cup-shaped leaves and it has trap-doors for catching prey.
To understand the general principle by which plants produce their leaves, a team of scientists from the John Innes Centre has been using aquatic plants as their model trying to investigate the mechanism in making its leaf shape.
In this study, it was identified that the simple gene shifts in gene activity at the leaf bud provide a mechanism that is flexible, and that allows the leaves to be produced in all shapes and sizes are made.
Professor Enrico Coen of the John Innes Centre says, “This study has led to the discovery of a general principle by which the leaves from
flat sheets to needle-like and curved shapes are formed.”It is found through a simple shift in the gene activity in the leaf bud, the complex leaf shapes of carnivorous plants are evolved from species having flat leaves. It is surprising to know that a simple mechanism can be the reason behind such a vast diversity of leaf shapes.
Previously, Professor Coen’s lab research had identified a polarity field– a kind of inbuilt cellular compass – which directs growth and shaping of the leaf from a sheet of cells.
The formation of cellular sheets, the identification of a second polarity field and also the domains of gene activity involved in setting it up were discovered by using molecular genetics analysis and computer modeling.
Several needle-like leaflets along with a trap are found on each leaf of Utricularia gibba. Analyzing them, it was seen that the initiation and the development of the trap were dependent on the gene activity, and this was restricted to a small area. The development of traps failed without these restrictions, and there was only the formation of needle-like leaflets.
This study presented a model where such gene activity shifts gave rise to a polarity field which oriented the tissue growth in plants. Altogether, it showed a simple mechanism that explains the diverse leaf forms and the formation of cup-shaped leaves from flat leaves.
You may ask why to study a cup-shaped leaf to find the general principle of making leaves. Answering this, Professor Coen explains, “If you want to understand why water boils at 100oC, you have to look for situations where it doesn’t, like the top of Mount Everest where it boils at 70oC. By doing this, we can know that the boiling point of water has the general principle that the boiling point depends on the air pressure. Likewise, to understand the reason why most leaves are flat, studying the exceptions like the leaves of some carnivorous plants is beneficial.
Plants sustain life on the planet by harvesting light and providing us energy and food. The flatness of leaves is an essential factor in how plants mechanism works. Understanding the principle of leaf formation and leaf shape mechanism, scientists have a better go at developing sustainable crops.
This study appears in Science.
Editor’s Note: Leaf Shape Mechanism Discovery. How are leaves made? Formation of leaf shape. Identifying the mechanism of making leaves.
