The small 295-bp ZmPht1; 5 promoter is sufficient to drive high-intensity expression of target genes, especially under phosphate deprivation conditions, and is therefore useful for crop improvement via transgenic techniques. Phosphate (Pi) deficiency has become a major challenge and limiting factor in world agricultural production. Manipulating the gene expression using appropriate promoters to improve the Pi absorption and utilization efficiency of crops could reduce the requirement for Pi fertilizers. In the study, a 295-bp strong promoter (M2P-7) of maize high-affinity phosphate transporter ZmPht1; 5 was isolated and functionally validated in transgenic Nicotiana benthamiana and maize by analyzing the ZmPht1; 5 promoter (M2P-1) and its 5′ truncated variants (M2P-2 ~ M2P-8) in different sizes under normal and Pi-deprivation conditions. The M2P-7 displayed the highest promoter activities among 5′ truncated fragments in all tested tissues of transgenic Nicotiana benthamiana at different development stages, which was 1.5 and 3 times higher than the well-used CaMV35S promoter under normal and Pi-deprivation conditions, respectively. In maize, the M2P-7 promoter activity was comparable to the maize ubiquitin1 promoter widely used in monocots under normal condition, which was about 1.3 times that of the ubiquitin1 promoter under Pi-deprivation environments. Moreover, the M2P-7 fragment is only 295 bp in length, thus reducing the construct size, and is therefore beneficial for genetic transformation. Thus, the small promoter M2P-7 of plant origin could be of great use for monocotyledonous and dicotyledonous crop improvement via transgenic techniques based on its promoter activities, expression patterns and small size.

中文翻译：

---

玉米高亲和磷酸转运蛋白基因ZmPht1 295 bp强启动子的分离与鉴定 5 在转基因本氏烟草和玉米中

小的 295-bp ZmPht1；5启动子足以驱动靶基因的高强度表达，特别是在磷酸盐剥夺条件下，因此可用于通过转基因技术改良作物。磷酸盐（Pi）缺乏已成为世界农业生产的主要挑战和限制因素。使用合适的启动子调控基因表达以提高作物对磷的吸收和利用效率，可以减少对磷肥的需求。在该研究中，玉米高亲和力磷酸转运蛋白 ZmPht1 的 295-bp 强启动子 (M2P-7)；通过分析 ZmPht1 在转基因本氏烟草和玉米中分离和功能验证了 5 个；在正常和 Pi 剥夺条件下，不同大小的 5 个启动子 (M2P-1) 及其 5' 截短变体 (M2P-2 ~ M2P-8)。M2P-7在转基因本氏烟草所有受试组织中不同发育阶段的5'截短片段中表现出最高的启动子活性，分别是正常和Pi剥夺条件下常用的CaMV35S启动子的1.5倍和3倍。 . 在玉米中，M2P-7启动子的活性与正常条件下广泛用于单子叶植物的玉米ubiquitin1启动子相当，是Pi剥夺环境下ubiquitin1启动子活性的1.3倍左右。此外，M2P-7 片段长度仅为 295 bp，从而减少了构建体的大小，因此有利于遗传转化。因此，植物来源的小启动子 M2P-7 可以通过基于其启动子活性的转基因技术对单子叶和双子叶作物的改良有很大的用途，