Improving Leaf GOGAT Activity After the Post-Silking Period Contributes to High Grain Yield with Reduced Nitrogen in N-Efficient Maize

作者：Haoyu Li, Yanbing Wang, Jian Wang, Meng Zhang, Wenbo Liu, Xiangling Li, Xiaohu Lin · 发表于：Agronomy · 年份：2025 · DOI：10.3390/agronomy15061379 · 被引用次数：5 · 研究领域：Crop Yield and Soil Fertility、Plant nutrient uptake and metabolism、Rice Cultivation and Yield Improvement

Breeding and cultivating low-N-efficient maize varieties to obtain high yields with less N fertilizer is important for addressing food demands and environmental pollution. However, few studies have investigated the physiological characteristics of low-N-efficient maize varieties. Therefore, we performed an experiment over four years to test two maize varieties (low-N-efficient variety: JNK728, and high-N-efficient variety: XY335) and five N application rates (N120: 120 kg·ha−1, N180: 180 kg·ha−1, N240: 240 kg·ha−1, N300: 300 kg·ha−1, and N360: 360 kg·ha−1). The optimal N application rates for JNK728 and XY335 were N180 and N300, which obtained the highest yields (11,754 and 12,752 kg·ha−1, respectively), N uptake efficiencies (1.32 and 0.93 kg·kg−1), and N harvest index (67.94% and 61.98%), compared with other N application rates. The key period for plant N accumulation was the R1–R6 stage, which contributed 35.2–49.7% and 40.8–53.8% to plant N accumulation at the maturation stage in JNK728 and XY335, respectively. In addition, N accumulation in the grain accounted for more than half (51.8–63.2%) of the total N accumulation in plants, and the leaf N transport amount after the post-silking stage was the primary source of grain N accumulation in both JNK728 and XY335. We also explored the key enzymes and genes related to the N transport amount and efficiency in leaves in the two maize varieties, and found that GOGAT was the key enzyme and GOGAT2 was the key gene for JNK728, whe...