Hydrogen peroxide protects plants against sun damage

June 29, 2017, University of Exeter
Chloroplasts (coloured red) associated with a nucleus. The nucleus appears green due to the fluorescent hydrogen peroxide sensing protein (HyPer). Credit: University of Exeter

Plants use hydrogen peroxide (H2O2) - best known for use in bleach and hair treatments - to control how their cells react to varying levels of light, new research shows.

The chemical is a by-product of photosynthesis in parts of plant called chloroplasts.

The signalling role of hydrogen peroxide had previously been suspected, but this study - by the University of Exeter and the University of Essex - is the first to discover where and how it happens.

"It's important for to be able to detect how much light there is, so they can make the most of it for photosynthesis," said Professor Nick Smirnoff, of the University of Exeter.

"They also have to adjust to protect themselves, as high levels of light can damage leaves - similar in some ways to how we humans get sunburn on our skin."

Professor Phil Mullineaux, of the University of Essex, said: "We know that there are a lot of different signals sent to to switch on genes and reorganise the way cells work, but this is the first time these signals have been observed moving from the chloroplasts (where photosynthesis takes place) to the nucleus."

The study was funded by the UK Biotechnology and Biological Sciences Research Council (BBSRC).

Using a fluorescent protein that detects hydrogen peroxide, the researchers observed how H2O2 moves from chloroplasts and can be detected in cell nuclei.

Plants' genes are located in the nuclei, and the process discovered shows how plants activate the genes needed for the leaves to adapt to the potentially damaging effects of bright light. This process of chloroplasts communicating with the nucleus ensures that plants continue to protect and adjust to prevailing conditions. Photosynthesis in crop plants determines how well they grow and yield.

The scientists also found that some of the chloroplasts which produce the H2O2 signal are attached to the cell nucleus, allowing them to pass the chemical effectively.

Lead author Dr Marino Exposito-Rodriguez, formerly of the University of Exeter but now at the University of Essex, said: "This breakthrough was made possible by the development of the fluorescent protein sensors, which allowed us to observe the movement of H2O2 in plant cells in real time."

The paper, published in the journal Nature Communications, is entitled: "Photosynthesis-dependent H2O2 transfer from chloroplasts to nuclei provides a high-light signalling mechanism."

Explore further: Collapsed chloroplasts are targeted in self-eating process

Related Stories

Collapsed chloroplasts are targeted in self-eating process

February 8, 2017

Researchers at Tohoku University have identified a previously uncharacterized type of autophagy, during which an autophagic process termed chlorophagy removes collapsed chloroplasts in plant leaves. The findings could lead ...

Lending plants a hand to survive drought

June 26, 2017

The findings have helped some plants survive 50 percent longer in drought conditions, and could eventually benefit major crops such as barley, rice and wheat, which are crucial to world food supplies.

Plants let chloroplasts know the time

March 14, 2013

(Phys.org) —Plant cells communicate information about the time of day to their chloroplasts, the part of their cells that underpins all agricultural productivity on Earth, researchers at the University of Bristol have demonstrated ...

Recommended for you

EPA adviser is promoting harmful ideas, scientists say

March 22, 2019

The Trump administration's reliance on industry-funded environmental specialists is again coming under fire, this time by researchers who say that Louis Anthony "Tony" Cox Jr., who leads a key Environmental Protection Agency ...

Coffee-based colloids for direct solar absorption

March 22, 2019

Solar energy is one of the most promising resources to help reduce fossil fuel consumption and mitigate greenhouse gas emissions to power a sustainable future. Devices presently in use to convert solar energy into thermal ...

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.