Biological complexity: plant growth complex protein control (Introduction)

by David Turell , Wednesday, January 09, 2019, 22:02 (2145 days ago) @ David Turell

New study on rooted plants show automatic controls with feedback loop controls:

https://www.sciencedaily.com/releases/2019/01/190109142645.htm

" Radial growth provides physical support to plants, yields everyday items like wood and cork, and plays a major role in converting atmospheric carbon into plant biomass.

"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. Radial growth is also responsible for producing our root and tuber vegetables such as turnips, carrots, sugar beet and potatoes.

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"Professor Ykä Helariutta's team at the Sainsbury Laboratory Cambridge University (SLCU) focused on the early (primary) stage of vascular development. They showed that in contrast to the late stage, during this early stage young phloem cells (protophloem) are initiating and organising the primary (procambial) stage of radial growth. They also described an underlying gene regulatory network and an integrating role for a newly identified group of mobile transcription factors.

"Together, their findings reveal some of the regulatory mechanisms that enable plants to continue to radially grow in a highly organised fashion, resulting in the concentric patterns seen in cross-sections of stems and roots. The key is the positioning of cells and a complex network of feedback signalling.

"Dr Mähönen's team combined individual cell lineage tracing and molecular genetics to show early-stage xylem cells, which had not yet differentiated, take over as the organiser and direct adjacent vascular cells to divide and function as stem cells: "We showed that this secondary development is a tightly controlled process and revealed a dynamic nature of the organiser. Differentiation of the organiser into a xylem vessel leads to formation of a new organiser in the adjacent cambial stem cell, thus ensuring the maintenance of the vascular cambium. We also identified a molecular mechanism that defines the stem cell organiser."

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"'Very early-stage phloem tissues (protophloem) are helping to guide the behaviour of cells and establish patterns of developmental potential that impact on future radial growth," says Professor Helariutta. "This is established through a group of mobile transcription factors that move from the protophloem sieve element (PSE) to the neighbouring cells, to promote cell division, and to develop their own identity. The activity of these mobile transcription factors is regulated by a set of signals of various chemical nature, such as plant hormones, other transcription factors and mobile microRNA species.'"

Comment: Automaticity in growth by feedback loops to control transcription factors, hormones and microRNA. This is h ow cells work in everyday projects.