Disruption of the phosphate-starvation response of oilseed rape suspension cells by the fungicide phosphonate
Disruption of the phosphate-starvation response of oilseed rape suspension cells by the fungicide phosphonate
复制标题
杀菌剂膦酸盐破坏油菜悬浮细胞的磷酸盐饥饿反应
作者：
M. Carswell;Bruce R. Grant;W. Plaxton
摘要。研究了抗真菌剂膦酸盐（Phi）对甘蓝型油菜（Brassica napus L. cv.）抗性的影响。研究了Jet Neuf细胞悬浮液对无机磷酸盐（Pi）饥饿的影响。在没有Pi的情况下，将细胞传代7 d，酸性磷酸酶（APase; EC 3.1.3.2）和焦磷酸（PPi）依赖性磷酸果糖激酶（PFP; EC 2.7.1.90）活性分别提高4.5倍和2.8倍，导致Vmax增加19倍，Km （Pi）减少14倍。在营养培养基中添加2 mM Phi，可显著降低Pi饥饿细胞的生长和Pi含量，但不降低Pi充足细胞的Pi含量，并在很大程度上消除了Pi饥饿依赖性诱导的PFP、APase和高亲和质膜Pi转运子。免疫印迹显示细胞含有三种在Pi胁迫下重新合成的APase异构体，Phi处理抑制了这一过程。磷酸盐处理后的pi饥饿细胞显著改变了Mrs为66、55、45和40 kDa的多肽在体内32p标记的相对程度。然而，Phi对pi -饥饿细胞的总腺苷酸库没有影响，到第7天，它比pi -充足细胞的总腺苷酸库低约32%。可溶性蛋白水平和丙酮酸激酶（EC 2.7.1.40）和atp依赖性磷酸果糖激酶（EC 2.7.1.11）的活性不受Pi饥饿和/或Phi处理的影响。Phi对pi饥渴型甘蓝型油菜幼苗生长、APase和PFP活性的影响与悬浮细胞相似。这些结果与高等植物中Phi作用的主要位点在信号转导链的水平上的假设是一致的，植物通过信号转导链在分子水平上感知和响应Pi胁迫。
Abstract. The influence of the anti-fungal agent phosphonate (Phi) on the response of oilseed rape (Brassica napus L. cv. Jet Neuf ) cell suspensions to inorganic phosphate (Pi) starvation was examined. Subculture of the cells for 7 d in the absence of Pi increased acid phosphatase (APase; EC 3.1.3.2) and pyrophosphate (PPi)-dependent phosphofructokinase (PFP; EC 2.7.1.90) activities by 4.5- and 2.8-fold, respectively, and led to a 19-fold increase in Vmax and a 14-fold decrease in Km (Pi) for Pi uptake. Addition of 2 mM Phi to the nutrient media caused dramatic reductions in the growth and Pi content of the Pi-starved, but not Pi-sufficient cells, and largely abolished the Pi-starvation-dependent induction of PFP, APase, and the high-affinity plasmalemma Pi translocator. Immunoblotting indicated the cells contain three APase isoforms that are synthesized de novo following Pi stress, and that Phi treatment represses this process. Phosphonate treatment of Pi-starved cells significantly altered the relative extent of in-vivo 32P-labelling of polypeptides having Mrs of 66, 55, 45 and 40 kDa. However, Phi had no effect on the total adenylate pool of Pi-starved cells which was about 32% lower than that of Pi-sufficient cells by day 7. Soluble protein levels, and activities of pyruvate kinase (EC 2.7.1.40) and ATP-dependent phosphofructokinase (EC 2.7.1.11) were unaffected by Pi starvation and/or Phi treatment. The effects of Phi on the growth, and APase and PFP activities of Pi-starved B. napus seedlings were similar to those observed in the suspension cells. The results are consistent with the hypothesis that a primary site of Phi action in higher plants is at the level of the signal transduction chain by which plants perceive and respond to Pi stress at the molecular level.
一个简单的计算机程序，具有用于分析酶动力学的统计测试。
影响因子：
2.7
作者：
Brooks,SP
通讯作者：
Brooks,SP