Beneath the Bud

 What am I looking at?

This image shows a young flower bud of a sand rock-cress plant that has been chemically cleared to make the outer tissue a transparent blue (1). This allows us to see the developing structures within the bud. The most apparent are the flower’s anthers, which are packed with pollen – seen here in red, yellow, and orange (2).

Biology in the background

For flowering plants, their flowers are the engines of reproduction. They release pollen, which fertilizes other flowers. They also gather pollen from other flowers to start the process of producing seeds that will grow into the next generation of plants.

However, flowers do most of their development under cover. Because flowers are so fragile, they develop within a protective casing called a bud. They stay within the bud until all the major parts of the flower are ready to perform their functions. Then the bud splits open and reveals the inner structure of the flower to the world so it can fulfill its reproductive destiny.

These buds are about 1 millimeter in diameter, or roughly 13 times bigger than the width of a human hair.

Technique

This image was created by chemically clearing the bud tissue and then imaging the resulting sample using confocal microscopy.