Microelement Research Center, College of Resources & Environment, Huazhong Agricultural University, Wuhan, P. R. China.
Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), MOA, Huazhong Agricultural University, Wuhan, P. R. China.
J Exp Bot. 2020 Jul 6;71(14):4321-4332. doi: 10.1093/jxb/eraa179.
Whilst constitutive overexpression of particular acid phosphatases (APases) can increase utilization of extracellular organic phosphate, negative effects are frequently observed in these transgenic plants under conditions of inorganic phosphate (Pi) sufficiency. In this study, we identified rice purple acid phosphatase 10c (OsPAP10c) as being a novel and major APase that exhibits activities associated both with the root surface and with secretion. Two constructs were used to generate the OsPAP10c-overexpression plants by driving its coding sequence with either a ubiquitin promoter (UP) or the OsPAP10c-native promoter (NP). Compared with the UP transgenic plants, lower expression levels and APase activities were observed in the NP plants. However, the UP and NP plants both showed a similar ability to degrade extracellular ATP and both promoted root growth. The growth performance and yield of the NP transgenic plants were better than the wild-type and UP plants in both hydroponic and field experiments irrespective of the level of Pi supply. Overexpression of APase by its native promoter therefore provides a potential way to improve crop production that might avoid increased APase activity in untargeted tissues and its inhibition of the growth of transgenic plants.
虽然特定酸性磷酸酶（APases）的组成型过表达可以增加细胞外有机磷酸盐的利用，但在无机磷酸盐（Pi）充足的条件下，这些转基因植物经常观察到负面效应。在这项研究中，我们鉴定了水稻紫色酸性磷酸酶 10c（OsPAP10c）是一种新型的主要 APase，它具有与根表面和分泌相关的活性。我们使用两种构建体通过用泛素启动子（UP）或 OsPAP10c 天然启动子（NP）驱动其编码序列来生成 OsPAP10c 过表达植物。与 UP 转基因植物相比，NP 植物中观察到的表达水平和 APase 活性较低。然而，UP 和 NP 植物都表现出相似的降解细胞外 ATP 的能力，并都促进了根的生长。在水培和田间实验中，NP 转基因植物的生长性能和产量均优于野生型和 UP 植物，无论 Pi 供应水平如何。通过其天然启动子过表达 APase 因此提供了一种提高作物产量的潜在方法，这可能避免了未靶向组织中 APase 活性的增加及其对转基因植物生长的抑制。
