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

Nov 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: Birds 'weigh' peanuts and choose heavier ones

Related Stories

Automated counting of tumor cells in blood

May 04, 2015

Biological and medical scientists have been using flow cytometry to count cancer cells for the past 40 years. But the large instruments are expensive and can only be operated by trained personnel. By contrast ...

Role of telomeres in plant stem cells discovered

Apr 30, 2015

The role played by telomeres in mammalian cells has been known for several years. It is also known that these non-coding DNA sequences, which are found at the ends of the chromosomes, protect them and are ...

Frontier science in ocean-going lab

Apr 21, 2015

Oceanographer Dr Martina Doblin is preparing for one of the most significant explorations of her career. In early June, a mobile laboratory known as the Micro-CSI will leave from Brisbane aboard Australia's ...

How to make trees grow bigger and quicker

Apr 16, 2015

Scientists at The University of Manchester have discovered a way to make trees grow bigger and faster, which could increase supplies of renewable resources and help trees cope with the effects of climate change.

Recommended for you

Birds 'weigh' peanuts and choose heavier ones

17 hours ago

Many animals feed on seeds, acorns or nuts. The common feature of these are that they have shells and there is no direct way to know what's inside. How do the animals know how much and what quality of food ...

Q&A: Why are antibiotics used in livestock?

May 22, 2015

Wal-Mart, the world's biggest retailer, is the latest company to ask its suppliers to curb the use of antibiotics in farm animals. Here's a rundown of what's driving the decision: ...

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.