New research sheds light on why plants change sex

January 10, 2017, University of Lincoln
Credit: University of Lincoln

Plants with a particular breeding system change their sex depending on how much light they receive, new scientific research has revealed.

The ability of to flower one year as male and the next as female, or vice versa, is well documented in 'dioecious' plants, however the causes of this ability to change gender have been largely unexplored in 'gynodioecious' plants until now.

Gynodioecy is a breeding system that is found in certain flowering plant species in which female and hermaphroditic plants coexist within a population. Gynodioecy is the evolutionary intermediate stage between hermaphrodite plants (each flower has both male and female parts) and dioecious populations (each plant having either only male or female flowers).

The ability to change sex in response to the environment has been studied extensively in dioecious plants but this new research has revealed that gynodioecious plants also change sex depending on their environment.

The results of a four-year study by researchers at the University of Lincoln, UK, show that the level of light received by the plant has a significant effect on sexual expression and reproductive output. The study found that in habitats with high levels of light, plants were more likely to change their sexual expression, and the researchers believe this is because sex lability (readiness to change) is costly and related to the availability of resources.

Dr Sandra Varga, Marie Curie Research Fellow at the University of Lincoln's School of Life Sciences, led the research. She explained: "The evolution and maintenance of such sexual polymorphism has been investigated by evolutionary biologists for decades. It is one of the most important developments in the evolution of plant breeding systems. However, understanding the causes and consequences is challenging because so many different factors might be involved in the process of changing from one sex to another.

"Our research clearly showed that sex expression was changeable over the course of the study, and was directly related to light availability."

Throughout the study, the researchers observed the behaviour of 326 different plants for four years and transplanted them between locations with both high and low levels to replicate the different environments they may encounter. For example, the wood cranesbill plants used in the study can often be found under dense forest canopies and in meadows and road verges.

The researchers monitored how the sex and reproductive outputs of the plants differed depending on their location, to garner a deeper understanding of how their behaviour is altered by their environment.

Explore further: Can trees really change sex?

More information: S. Varga et al. Light availability affects sex lability in a gynodioecious plant, American Journal of Botany (2016). DOI: 10.3732/ajb.1600158

Related Stories

Can trees really change sex?

November 5, 2015

The revelation that the UK's oldest tree is showing signs of switching sex has sparked much excitement in the world of horticultural science. The Fortingall yew (main image) in Perthshire, Scotland, having apparently spent ...

Flowers use physics to attract pollinators

December 5, 2016

A new review indicates that flowers may be able to manipulate the laws of physics, by playing with light, using mechanical tricks, and harnessing electrostatic forces to attract pollinators.

Science casts light on sex in the orchard

October 30, 2014

Persimmons are among the small club of plants with separate sexes—individual trees are either male or female. Now scientists at the University of California, Davis, and Kyoto University in Japan have discovered how sex ...

Pollinator competition may drive flower diversification

January 27, 2016

Male hummingbirds drive female birds away from their preferred yellow-flowered plant, which may have implications for flower diversification, according a study published Jan. 27, 2016 in the open-access journal PLOS ONE by ...

Recommended for you

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.