The gene that helps plant cells finding the right direction

Apr 30, 2014

Plant physiologist Stefano Pietra shows in his doctoral thesis that the SABRE gene is necessary for plants to coordinate the polarity of their cells. The gene "tells" all cells in a certain region what is up and what is down and how they should modify their form accordingly.

Plant cell growth is often coordinated within a tissue layer, a concept that researchers name planar polarity.

"How cells within a large area all get the information to orient in a similar way is still not entirely clear, but my research identifies a new player that is involved in this process, the SABRE gene," says Stefano Pietra.

He has analysed the position of small hairs on of the model plant Arabidopsis thaliana, a small weed. These hairs grow with a specific orientation – similar to those on the skin of animals and men that all point in the same direction. Hair orientation is very easy to observe, and the analysis gives insight on the mechanisms coordinating cell polarity in other parts of the organism.

In addition to coordinating the polarity of cells, Stefano Pietra also shows thatSABRE makes sure that cells divide neatly and form long straight files that align to the direction of root growth. If the SABRE gene is not functional, cell divisions are not perpendicular to the root growth direction, cell files are not straight, and the overall root morphology is affected.

Another role of SABRE is to stabilize patterning of the root surface, which is the coordinated decision of all cells in a file to either grow a hair or not. This selection is driven by the mechanisms that control how initially identical cells differentiate and acquire specific shapes and functions, an essential process in all multicellular organisms.

The exact way in which SABRE performs its functions is still unclear, but Stefano Pietra has discovered that the gene has an effect on the organization of the plant cytoskeleton, a scaffolding of small and very dynamic filaments and tubules that controls many cellular processes including shape acquisition and growth. Organization of the cytoskeleton could therefore be important in plants for coordinating the polarity of cells and the specification of their fate.

Not only plants, but also animals and humans need mechanisms to orient their and to tell them in which direction they should grow; when these mechanisms do not work the organisms have serious problems to develop and often die prematurely.

Genes similar to SABRE are present in many species, including men, but their function is still unknown.

"Having found one function of SABRE in plants, my research could help studying similar genes in other species. My study also opens the way for future studies on the role of the cytoskeleton and the exact relationship between SABRE and the cytoskeleton."

Explore further: Sex chromosomes—why the Y genes matter

More information: The thesis titled "Characterization of New Players in Planar Polarity Establishment in Arabidopsis" is available online: umu.diva-portal.org/smash/record.jsf?pid=diva2:711983&rvn=1 

Related Stories

The sweet growth of plant cells

Jun 16, 2011

An international collaboration team unravels the fundamental role that carbohydrates play in the root hairs of Arabidopsis thaliana and shows how cell growth is modulated in this species.

Plant cell architecture: Growth toward a light source

Nov 07, 2013

Inside every plant cell, a cytoskeleton provides an interior scaffolding to direct construction of the cell's walls, and thus the growth of the organism as a whole. Environmental and hormonal signals that modulate cell growth ...

Researchers identify key pathway for plant cell growth

Jan 23, 2014

For plants, the only way to grow is for cells to expand. Unlike animals, cell division in plants happens only within a tiny region of the root and stem apex, making cell expansion the critical path to increased ...

Recommended for you

Sex chromosomes—why the Y genes matter

2 hours ago

Several genes have been lost from the Y chromosome in humans and other mammals, according to research published in the open access journal Genome Biology. The study shows that essential Y genes are rescue ...

Better mouse model enables colon cancer research

16 hours ago

Every day, it seems, someone in some lab is "curing cancer." Well, it's easy to kill cancer cells in a lab, but in a human, it's a lot more complicated, which is why nearly all cancer drugs fail clinical ...

How to get high-quality RNA from chemically complex plants

May 26, 2015

Ask any molecular plant biologist about RNA extractions and you might just open up the floodgates to the woes of troubleshooting. RNA extraction is a notoriously tricky and sensitive lab procedure. New protocols out of the ...

Plant fertility—how hormones get around

May 26, 2015

Researchers at Tokyo Institute of Technology have identified a transporter protein at the heart of a number of plant processes associated with fertility and possibly aging.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.