CCMB team finds clues to Darwin’s ‘abominable mystery’ in common plant Premium

Understanding the evolution of flowering plants through the SHUKR gene sheds light on plant adaptation and survival in changing environments.

Life on the earth depends on plants. Microscopic aquatic plants and algae make most of the oxygen on the planet. The land plants are the primary producers of human and animal food. This is why it’s important to understand how they grow and reproduce.

In the last 450 million years, as plants slowly evolved from freshwater algae and moved from aquatic ecosystems to moist land to drier land, their life-cycles also changed significantly.

But something curious happened about 130 million years ago, soon after flowering plants first appeared. Fossils from that period suggest flowering plants diversified rapidly in terms of their anatomies and habitats. Evolution is understood to be a gradual process, and the rapid emergence of diverse flowering plants has thus been a puzzle. Charles Darwin called this an “abominable mystery”.

A recent paper by a team of researchers at the CSIR-Centre for Cellular and Molecular Biology (CCMB), Hyderabad, shed light on the molecular innovations in flowering plants that could help understand this mystery.

A plant’s life-cycle has two distinct phases: when it’s a gametophyte (gamete-making plant) and when it’s a sporophyte (spore-making plant). The phases dictate their anatomies and functions.

Gametophyte cells contain one set of genes and make either sperm or egg. The fusion of a sperm and an egg gives rise to a sporophyte. Each sporophyte contains two sets of genes, one from each contributing gamete.

When it matures, the sporophyte cells divide to make new cells called spores. The spores have novel combinations of a single set of genes — and the diversity here is responsible for creating plants with diverse traits within a population.