How did this zucchini plant cling to the zip tie?

Question

I'm somewhat curious to know how this zucchini plant "saw" the zip tie and managed to get closer and tie up.

What are the biological mechanisms that allow it to do so?

Answer 1

Plant movement is called tropism, and for your squash it's specifically thigmotropism, movement in response to touch. Your zuchinni didn't see the zip tie, it found it :-). Here is time lapse of a bean plant groping around.

Regarding the mechanism, Wikipedia explains it like this:

This behavior occurs due to unilateral growth inhibition. That is, the growth rate on the side of the stem which is being touched is slower than on the side opposite the touch. The resultant growth pattern is to attach and sometimes curl around the object which is touching the plant.

Answer 2

It didn't actually see anything.

The tendril did what tendrils do - It swung round and round (to anthropomorphize ) - blindly groping for anything to latch on to. As soon as it "felt" something - ie the cable tie here - it started trying to twirl around, curling around whatever part made contact with it.

I did do a bit of digging around, and while there is some evidence that light seeking does play a role in tendril development and where it grows towards ( https://nph.onlinelibrary.wiley.com/doi/pdfdirect/10.1111/nph.15073 ) It does not appear that even this would have played a significant role in "seeing" the zip tie.