Scientists in China studied how wheat plants have been genetically improved to use nitrogen more efficiently. They grew 32 wheat varieties from different time periods in a field with different nitrogen levels. They found that newer wheat varieties can take up and use nitrogen better than older ones, leading to higher yields with less fertilizer. The plants absorb more nitrogen before flowering, which helps them grow better. The leaves play a key role in absorbing and transferring nitrogen to the grains. Overall, the study shows that modern wheat varieties are better at using nitrogen efficiently, which helps them produce more grains with less nitrogen fertilizer.