玉米Proline responding 1(pro1)突变在蛋白合成和细胞...（三）
pro1突变体中脯氨酸缺乏引起细胞周期G1到S期转换的抑制
Pro1基因作为玉米中合成脯氨酸过程的关键酶，对玉米生理生化的影响是多方面且重要的。RNA-seq (Figure 5)证实pro1突变体中脯氨酸的缺乏引起了细胞周期相关基因、DNA复制相关基因以及细胞增殖相关基因表达的下调，体外添加脯氨酸后这些基因表达回复至野生型水平(Figure 6A、B)。脯氨酸作为一种重要氨基酸，它的信号分子作用会涉及细胞内部多种多样的生理平衡和生化过程：通过GCN2，mTOR等与氨基酸缺乏偶合的调控环节，可改变细胞原有的基因表达模式，涉及蛋白合成与细胞周期等生命活动，诱导细胞进入修复，停滞或凋亡的模式。
Figure 5 Gene Expression Profiling Graphs of Wild type and pro1-ref.
(A) Graphs show log2 ratios of gene expression in 14 DAG seedlings of wild type and pro1-ref.
(B) Graphs show a scatter plot comparing gene expression in 14 DAG seedlings of wild type and pro1-ref.
(C) Graphs show genes identified as differentially expressed by Fisher’s test (red dots).
Figure 6 Cell Cycle-Related Gene Expression Analysis in Wild type and pro1-ref.
(A) RNA expression of cell cycle-related genes based on RT-PCR analysis of 14 DAG wild type and pro1-ref seedlings cultivated in 1/2 MS culture medium supplemented with various concentrations of L-proline and L-glutamate. wt, wild type; pro1, pro1-ref.
(B) Expression of various cell cycle-related genes in 14 DAG wild type and pro1-ref seedlings cultivated in 1/2 MS culture medium supplemented with various concentrations of L-proline. Ubiquitin was used as an internal control. For each sample, three technical and two independent biological replicates were performed. Error bars represent SD. wt, wild type; pro1, pro1-ref.
