The researchers studied how different temperatures affect the production of starch in rice grains. They looked at two types of rice and two temperature conditions in a controlled environment. They found that high temperatures at the beginning of grain filling led to higher levels of sugar and starch, as well as increased enzyme activity. However, as the grains developed, the relationship between enzyme activity, sugar, and starch became more complex. Enzymes like sucrose synthase and soluble starch synthase were more affected by temperature changes than others. The ratio of amylose to total starch was lower in high temperatures, mainly due to lower activity of a specific enzyme called granule bound starch synthase. Overall, temperature plays a significant role in how starch is produced in rice grains.