There is a shape match between the receptor and the molecule attached to it, such as between a key and a lock

Orange is stimulated from smoke not heat. Ethylene was the key factor.

Why Avocade is riped in the sack with apple? All fruit release ethylene.

First riped orange release ethylene, so brother oranges are also ripening because of ethylene. Color of fruit is the way of expanding their gene. So, this is the evolutionary reason.

Ethelene이 중세시대 전등에서 발생했는데, 이것때문에 식물들의 잎이 다 져버렸고, 에틸렌에 내성이 있는 난이 실내 식물로 각광을 받게 되었다.

When plants scent ethylene, it is not elongate and they are fat.

Plants are communicating via chemicals. So they communicate via smell.

What kind of attack result in different chemicals.