The bonsai effect: Wounded plants make jasmonates, inhibiting cell division, stunting growth

November 11, 2008

It is well known that plants growing under unfavourable conditions are generally smaller than those growing in stress-free conditions: indeed it is estimated that in the US, abiotic stress reduces the yield of agricultural crops by an average of 22%. A spectacular example of the effect of stress – in this case, repeated wounding – on plant growth is given by bonsai trees, in which every aspect of their stature, including height, girth, and size of leaves, is uniformly reduced to as little as 5% of that of their untreated sister trees. However, the mechanism of wound-induced stunting remains obscure.

Plant growth results from divisions of "stem cells" in apical meristems that are located in the very tips of green shoots and roots. The shoot apical meristems are not only tiny, (0.1 to 0.3 mm diameter), but are normally hidden from view by the very young leaves emerging from the base of the meristem. Thus, the initial growth and shape of leaves is by cell division, and more than 90% of leaf growth is by subsequent cell expansion.

Reporting in the online, open-access journal PLoS ONE on November 11, Yi Zhang and John Turner at the University of East Anglia found that when leaves of the model plant Arabidopsis are wounded, cell division in the apical meristem is reduced, growth of the plant is arrested within days, and the new leaves grow to only one-half of their normal size although the size of leaf cells is unaffected.

Unexpectedly, the suppression of cell division in the apical meristem occurs through a signal pathway initiated by the wound hormone, jasmonate, which is synthesised in the damaged mature leaves. Mutant Arabidopsis lines unable to synthesise or to respond to jasmonate are not only larger than normal plants, but their growth is not reduced by the wound stress.

The researchers note that this finding opens the possibility of improving crop growth through the manipulation of the jasmonate signal pathway.

Citation: Zhang Y, Turner JG (2008) Wound-Induced Endogenous Jasmonates Stunt Plant Growth by Inhibiting Mitosis. PLoS ONE 3(11): e3699. doi:10.1371/journal.pone.0003699 dx.plos.org/10.1371/journal.pone.0003699

Source: Public Library of Science

Explore further: Helping plants fight off pathogens by enhancing their immune systems

Related Stories

Unlocking the biofuel energy stored in plant cell walls

June 10, 2015

By virtue of their chloroplasts, plants are superb harvesters of solar energy. They use it to build leaves, flowers, fruits, stems, and roots. We harvest a small percentage of that energy in the form of food and a smaller ...

Injectable gel fills wounds and promotes tissue regeneration

June 8, 2015

Researchers from the UCLA Henry Samueli School of Engineering and Applied Science have developed an injectable hydrogel that helps skin wounds heal more quickly. The material creates an instant scaffold that allows new tissue ...

Recommended for you

Can genes make us liberal or conservative?

August 4, 2015

Aristotle may have been more on the money than he realised in saying man is a political animal, according to research published Wednesday linking genes with liberal or conservative leanings.

Galaxies show appetite for growth

August 4, 2015

The extent to which galaxies consume one another has been revealed in research. Findings from the study help to explain how galaxies such as the Milky Way were formed.

Robo-whiskers mimic animals exploring their surroundings

August 4, 2015

Many mammals, including seals and rats, rely on their whiskers to sense their way through dark environments. Inspired by these animals, scientists working at the University of Illinois at Urbana-Champaign and Illinois' Advanced ...

0 comments

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.