The first scientific discovery about pollination and pollen!

Pollination is known as the hallmark of flowering plants, and pollinating animals such as bees and birds provide the world’s food supply.

But a new study raises the possibility that animal-assisted pollination appeared at sea long before plants moved ashore.

The study, led by research teams from France and Chile, is the first documented type of seaweed that depends on small marine crustaceans filled with pollen-like spores to reproduce.

Because the red algae Gracilaria gracilis evolved long before land plants, the researchers say their study shows that animal-assisted pollination emerged about 650 million years ago in the oceans, once a suitable pollinator was available. And on land, flowering plants, bearing seeds and gymnosperms, or male sex cells, or gametes, in the form of pollen, carried by wind, water or insects taken by surprise, in the hope of landing on their female counterpart somewhere far away.

The scientists then discovered that algae (a type of rootless, non-flowering plant classified as an algal plant) and some fungi also use animals and insects to facilitate reproduction, refuting everything they knew about animal pollination.

Although it is often discussed, researchers believe that it originated with land plants around 140 million years ago – or at least during the Mesozoic era, which dates back approximately 252 million years.

And just a few years ago, scientists discovered that marine invertebrates that carry the sperm of algae feed on them, throwing out into the sea the old theory that the oceans are devoid of pollinators.

A new study by Emma Laffaut, a PhD student in evolutionary biology at the Sorbonne University in Paris, and her colleagues describes how tiny crustaceans called the isopods Idotea balthica help to fertilize a species of red algae, G. gracilis, that evolved 500 million years ago. A long time ago, when wild plants appeared.

“The researchers’ study expands the diversity and history of animal transmission of male gametes by taking into account the concept of pollination by land plants,” Jeff Ollerton and Zhong Shen Ren, two ecologists from the Kunming Institute of Botany of the Chinese Academy of Sciences. , wrote in a perspective attached to an article in Science, to algae and may have pushed them into the earliest evolution of marine invertebrates.”

G. gracilis also differs from most other seaweeds in that the male gametes do not have flagella to propel them through the water and remain wandering in the ocean unless they manage to cut the ridge on a passing creature, as this new work suggests. . do many times.

“Our results demonstrate for the first time that biotic interactions significantly increase the likelihood of fertilization in algae,” the researchers wrote.

But they haven’t yet compared this crustacean pollination to the spread of pollen along water currents to see which plays a big role.

The origin of plants using animal pollinators remains wide open, given that researchers have only drawn conclusions based on the evolutionary history of the animals involved.

However, in a world where rapid human-induced climate changes are occurring, these delicate relationships between plants or algae and animals are under threat as much as the ecosystems that support them.

Seaweeds such as G. gracilis thrive in still coastal waters when coastlines are eroded by storms and sea levels slowly rise towards land. Meanwhile, ocean acidification could weaken crustacean exoskeletons, although this needs to be studied in isopods.

The study was published in a journal. The science.

Source: Science Alert.