Nav: Home

Plant peptide helps roots to branch out in the right places

January 18, 2019

How do plants space out their roots? A Japanese research team has identified a peptide and its receptor that help lateral roots to grow with the right spacing. The findings were published on December 20, 2018 in the online edition of Developmental Cell.

The team was led by Professor Hidehiro Fukaki (Graduate School of Science, Kobe University), Researcher Koichi Toyokura (currently JSPS Research Fellow at Osaka University) and Project Assistant Professor Tatsuaki Goh (currently Assistant Professor at the Nara Institute of Science and Technology) in collaboration with Professor Yoshikatsu Matsubayashi and Assistant Professor Hidefumi Shinohara (both from Nagoya University) and other researchers from the Nara Institute of Science and Technology, Associated Professor Koichi Fujimoto (Osaka University) and Assistant Professor Yuki Kondo (the University of Tokyo).

Plant root systems are mainly shaped by the lateral roots that grow from tissue inside the existing roots. These roots form from "lateral root founder cells" that are positioned at regularly-spaced intervals at a distance from the meristem tissue (tissue responsible for growth). Previous studies using Arabidopsis plants showed that lateral root founder cells are made from sites where there is high response to the chemical auxin, and indicated that transcription factor LBD16 induced by auxin may inhibit the cells near lateral root founder cells from forming roots.

This time a joint research team, using plant model Arabidopsis, searched for the gene that is activated by transcription factor LBD16 and successfully identified the TOLS2 gene. The TOLS2 gene is mainly expressed in lateral root founder cells and root germs. In Arabidopsis plants that overexpress TOLS2, the number of lateral roots decreases (figure 1), indicating that the TOLS2 gene can inhibit the formation of lateral root founder cells. The team analyzed secretions from plants with overexpression of TOLS2 and revealed that the mature TOLS2 peptide is formed from 11 amino acids. When they artificially created mature TOLS2 peptide and added it to a wild-type Arabidopsis, the number of lateral root founder cells and lateral roots decreased (figure 2).

Based on further investigation, the research team identified the receptor for TOLS2 as RLK7. RLK7 proteins express in the inner sheath of the roots (where the lateral root founder cells are located), the endodermis and the dermal layer, but RLK7 expression could not be found in the lateral root founder cells. It is likely that these proteins suppress the formation of lateral roots in cells adjacent to lateral root founder cells.

Next, using CRISPR/Cas9 genome editing technology, the team investigated how lateral roots form in other genetically-altered plant samples. Their results confirmed that the TOLS2 peptide and the RLK7 receptor are necessary to preserve the correct spacing between lateral root founder cells. From this analysis the research team proposed that Arabidopsis, by responding to auxin and inducing TOLS2 peptide in lateral root founder cells, through RLK7 receptors inhibits nearby lateral root founder cells in a non-cell-autonomous manner (figure 3).

Professor Fukaki comments: "If the mechanism for TOLS2 peptide-based inhibition of nearby lateral root founder cells is clarified in Arabidopsis, this will help us to understand root formation mechanisms in other plants such as crops and trees. And if other plants contain peptides that fulfil the same function as the TOLS2 peptide, we could potentially use this mechanism to artificially control root formation patterns for crops and trees."
-end-


Kobe University

Related Arabidopsis Articles:

First PhytoFrontiers™ paper discusses arabidopsis response to caterpillars
In their PhytoFrontiers article, Jacquie and colleagues, including first author Zhihong Zhang, who just completed her MSc studies and is interested in the regulation of plant responses to caterpillar herbivory, compare plant responses to two noctuid caterpillar species that are both considered to be ''generalist'' caterpillars.
Success in promoting plant growth for biodiesel
Scientists of Waseda University in Japan succeeded in promoting plant growth and increasing seed yield by heterologous expression of protein from Arabidopsis (artificially modified high-speed motor protein) in Camelina sativa, which is expected as a useful plant for biodiesel.
Applying CRISPR beyond Arabidopsis thaliana
In the plant sciences, CRISPR--the bacterial gene editing toolbox that enables more precise and efficient editing of genomic sequences than previously possible--has initially been applied with genetic model organisms like Arabidopsis thaliana.
A molecular map for the plant sciences
Plants are essential for life on earth. They provide food for essentially all organisms, oxygen for breathing, and they regulate the climate of the planet.
Putting a finger on plant stress response
Researchers from the University of Tsukuba have found that a PHD zinc finger-like domain in SUMO E3 ligase SIZ1 is essential for protein function in Arabidopsis.
Better anchor roots help crops grow in poor soils
A newly discovered plant metabolite that promotes anchor root growth may prove valuable in helping crops grow in nutrient-deficient soils.
Plant peptide helps roots to branch out in the right places
How do plants space out their roots? A Japanese research team has identified a peptide and its receptor that help lateral roots to grow with the right spacing.
Scientists identify how plants sense temperature
A UC Riverside researcher is leading a team exploring how plants respond to temperature.
Scientists consider climate change-resistant crops
Meng Chen and his team identified the genetic mechanism used by all plants as they respond to daylight conditions as well as the ability to sense temperature.
Network biology reveals pathogen targets in the model plant Arabidopsis thaliana
Using systems biology, researchers successfully identified previously unknown protein targets of plant pathogens in the flowering plant Arabidopsis thaliana, employing some of the same methods used to analyze social networks or biological networks.
More Arabidopsis News and Arabidopsis Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.