Time-Lapse Photography Captures the Secret Lives of Plants

Time-Lapse Photography Captures the Secret Lives of Plants:  Not quite Day of the Triffids, but in response to a stimulus, plants move and r...

Time-Lapse Photography Captures the Secret Lives of Plants: 

Not quite Day of the Triffids, but in response to a stimulus, plants move and react to external stimuli. Anyone familiar with the sensitivity plant has seen how quickly a plant can move. Other plant movements are easier to capture using time-lapse photography.  

I started examining plant movement when I noticed separate bean vines finding each other high above the big bag garden.

I extended the tower to support the vines.

Then I set up an iPhone with the Time Lapse app to capture the vines wrapping around the supports. Six hours later, the captured video showed the vines wrapping around the support.

How does the plant "know" when and where to grow? 

Plants grow in response to stimuli: Sunlight, gravity, and in the case of the vines, also touch. Plant hormones (phyto-hormones), control plant growth, creating many of the familiar plants responses. 

Here's a very simplified analogy of how hormones work. I have a smart home. I can tell Alexa to turn on and off various lights, or guard the house. The commands I give Alexa are like hormones. In an organism, each cell has the same blueprint (DNA), hormones are the commands that control how the plans are expressed, or turned off and on.  

It is far more complex than that, but hormones have been part of life since the start of life on earth.

Here are some of the common plant hormones according to my California Master Gardener Book:

Plant Hormone:    

• Effect

Auxins

• regulate cell enlargement
• suppress lateral bud development
• direct shoot growth toward light
• direct horizontal growth upward
• and more

Gibberellins

• regulate cell division
• activate enzymes in germinating seeds
• and more

Cytokinins

• stimulate cell division
• and more

Ethylene

• accelerates fruit ripening
• induces flowering in some species
• hastens senescence and abscission of leaves and fruits.
• and more

Abscisic acid

• regulates and promotes dormancy in shoots and seeds
• responsible for abscission (dropping-off) of leaves on deciduous plants and closing of stomata on leaves under stress.
• and more

By the way, you may have heard of using a ripe banana to ripen your avocados or tomatoes. The banana is releasing ethylene and the un-ripe fruit is responding. 

The bending vines trick? A phyto-hormone signals cells on the opposite of the touched stem to elongate, bending the vine toward the stimulus. Which hormone do you think is responsible?

Here is another plant moving, Calendula responding to sunlight in the morning:

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