Earth’s First Plants Likely to Have Been Branched
Published:16 Apr.2023 Source:Karlsruher Institut für Technologie (KIT)
By studying the mechanisms responsible for branching, the team have determined what the first land plants are likely to have looked like millions of years ago. Despite fundamentally different patterns in growth, their research has identified a common mechanism for branching in vascular plants. Dr Jill Harrison explained: “Diverse shapes abound in the dominant flowering plant group, and gardeners will be familiar with ‘pinching out plants’ shoot tips to stimulate side branch growth, leading to a bushier overall form.”
“However, unlike flowering plants, other vascular plants branch by splitting the shoot apex into two during growth, a process known as ‘dichotomy’”. As an ancient vascular plant lineage that formed coal seams during the Carboniferous era, lycophytes preserve the ancestral pattern of dichotomous branching.
Using surgical experiments in a lycophyte, researchers at the University of Bristol have discovered that dichotomy is regulated by short range auxin transport and co-ordinated in different parts of the plant by long range auxin transport. The findings showed that both flowering plant and lycophyte branching are regulated by auxin transport imply that similar mechanisms were present in the earliest vascular plants around 420 million years ago.