Understanding radial growth in plants

Understanding radial growth in plants Today’s Video of the Day from the University of Cambridge describes how researchers are gaining a better understanding of radial growth in plants.

The vascular cambium is a thin, microscopic layer underneath tree bark that is responsible for all of the outward growth of wood and trees.

Despite the important role of the vascular cambium, very little was known about how it worked. To investigate, the scientists focused on stem cells.

The study revealed that early stage young phloem cells, which transport nutrients, initiate and organize the primary stage of radial growth. Radial growth also produces specialised vascular tissues that transport water and nutrients around plants and is visible as concentric patterns known as annual growth rings in tree trunk cross-sections. In many cases, plants and trees continue this outwards growth for their entire lifetime. 

One of the extraordinary features of plants is their growth capacity. Depending on the species and the environment, body forms are manifold and, at the same time, constantly reshaped. An important basis of this plastic variation and life-long accumulation of biomass is radial growth. Some extant land plants — including liverworts, hornworts and mosses (bryophytes) — still exclusively rely on primary growth and, in this respect, resemble the first land plants. Fossils indicate that those plants had one central strand of water-conducting tissue which was notably small compared with the diameter of the whole organ.

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By Chrissy Sexton, Earth.com Staff Writer

Video Credit: University of Cambridge