If a plant is living in a cold environment, which physiological change would the most with the cool temperatures?

Plants has the ability to survive in col environment due to having the ability of adaptation

Explanation:

In a cold environment, Plant species can live in that environment with the ability of adapt will make them live longer in those conditions

Plants that grow  in  certain arctic regions  that are arctic, grow close to the ground in a specific shape that helps them to shed snow from them and they are not big.

These plants have the ability to trap every inch of sunlight available for the process of photosynthesis. due to vascular system which is developed by these plants.  In dormant conditions, some of the plants shed their leaves.

Trees like evergreen  have thick waxy coating that averts the loss of water.

the answer to you question is   jet streams