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We always think that it's OK for us to leave our
plants home during our vacation as plants won't scream like pets, right?
A recent study done by a
group of scientists at the Tel Aviv University has discovered that some plants
will scream when they are under stress.
The research was carried
out on tomato plants and tobacco plants by cutting their stems (茎) and depriving (剥夺) them of water. A microphone
was placed 10cm away from them. When their stems were cut, the plants started "screaming" between 20 and 100
kilohertz, and the scientists guess that this scream is probably meant to warn
other plants nearby.
When the tomato plants' stems were cut, 25
ultrasonic (超声的) pain sounds were recorded
in an hour, and at the same time, 15 ultrasonic pain sounds were recorded from
the tobacco plants. When they were deprived of water, the tomato plants
recorded even more pain sounds with 35 pain sounds in an hour while the tobacco
plants recorded about 11 pain sounds.
The plants also acted
differently to different kinds of stresses. For example, the tobacco plants
gave out a stronger "scream" when they were deprived of
water than when their stems were cut. But plants that were in no immediate (立刻的) danger gave out less than
one ultrasonic sound per hour.
The group of scientists
said that plants are not as quiet as we had always thought, but in fact their
voices are so high-pitched that we just can't hear them.
Last year, another study has
found out that plants feel pain when they are touched or hurt and they will
give off a terrible smell.
