When under threat from animals or infection, they can deliberately kill off parts of themselves as part of a longer-term protective strategy, experts from Vienna University say.

Tactical suicide: An infected plant kills off parts of itself, seen as withered spots, to stop the spread of the disease
In the case of infection, the death of the infected part of the plant meant that the infection also dies out with the part of the plant chosen to be killed off.
Another reason plants sacrifice parts of themselves is to minimise their profile when struck by disease so plant eating mammals or insects foraging for food move on and look elsewhere.
Study leader Andreas Bachmair, from the department of biochemistry and cell biology at Vienna University, said: 'It is often a wrong assumption that immense heat or ozone kills a plant.
'Most of the time plants create a special programme themselves to save what can be saved.
'Despite the voluntary death of certain parts, it remains alive in its core.'
Bachmair said plants had developed different protection strategies than animals because they couldn't run away from danger.
He said: 'Instead of relocation, they do without certain parts when there is a problem.'
The team are now trying to find out how the plant's suicidal tendencies are related to their ability to shed their leaves in autumn.
In another surprising parallel to animals, plants also have an immune system in the form of chemical weapons to combat influences like fungal infestation.
Source: Dailymail.co.uk