The researchers studied how wheat plants change as their leaves age in the field. They found that as the leaves age, certain pigments decrease while others increase, helping to protect the plant from too much sunlight. The efficiency of photosynthesis also decreases as the leaves age, especially when exposed to high light. This decrease is partly due to a process called the xanthophyll cycle, which helps to protect the plant from damage caused by too much light. Overall, the study shows that aging leaves adjust their pigment composition and photosynthesis to cope with changing light conditions.