PDF(Pubmed)
Abstract：
Applying phosphate-solubilizing bacteria (PSB) as biofertilizers has enormous potential for sustainable agriculture. Despite this, there is still a lack of information regarding the expression of key genes related to phosphate-solubilization (PS) and efficient formulation strategies. In this study, we investigated rock PS by Ochrobactrum sp. SSR (DSM 109610) by relating it to bacterial gene expression and searching for an efficient formulation. The quantitative PCR (qPCR) primers were designed for PS marker genes glucose dehydrogenase (gcd), pyrroloquinoline quinone biosynthesis protein C (pqqC), and phosphatase (pho). The SSR-inoculated soil supplemented with rock phosphate (RP) showed a 6-fold higher expression of pqqC and pho compared to inoculated soil without RP. Additionally, an increase in plant phosphorous (P) (2%), available soil P (4.7%), and alkaline phosphatase (6%) activity was observed in PSB-inoculated plants supplemented with RP. The root architecture improved by SSR, with higher root length, diameter, and volume. Ochrobactrum sp. SSR was further used to design bioformulations with two well-characterized PS, Enterobacter spp. DSM 109592 and DSM 109593, using the four organic amendments, biochar, compost, filter mud (FM), and humic acid. All four carrier materials maintained adequate survival and inoculum shelf life of the bacterium, as indicated by the field emission scanning electron microscopy analysis. The FM-based bioformulation was most efficacious and enhanced not only wheat grain yield (4-9%) but also seed P (9%). Moreover, FM-based bioformulation enhanced soil available P (8.5-11%) and phosphatase activity (4-5%). Positive correlations were observed between the PSB solubilization in the presence of different insoluble P sources, and soil available P, soil phosphatase activity, seed P content, and grain yield of the field grown inoculated wheat variety Faisalabad-2008, when di-ammonium phosphate fertilizer application was reduced by 20%. This study reports for the first time the marker gene expression of an inoculated PSB strain and provides a valuable groundwork to design field scale formulations that can maintain inoculum dynamics and increase its shelf life. This may constitute a step-change in the sustainable cultivation of wheat under the P-deficient soil conditions.
摘要：
将溶解磷酸盐的细菌（PSB）用作生物肥料具有可持续农业的巨大潜力。尽管如此,目前仍然缺乏与磷酸盐溶解(PS)相关的关键基因表达和有效的配方策略的信息.在这项研究中,我们通过Ochrobactrumsp。研究了岩石PS。SSR（DSM109610）通过将其与细菌基因表达相关联并寻找有效的制剂。设计了PS标记基因葡萄糖脱氢酶(gcd)的定量PCR(qPCR)引物,吡咯并喹啉醌生物合成蛋白C(pqqC),和磷酸酶（pho）。与不含RP的接种土壤相比，补充有磷矿（RP）的SSR接种土壤显示pqqC和pho的表达高6倍。此外,植物磷（P）增加（2%），土壤有效磷（4.7%），在补充有RP的PSB接种植物中观察到碱性磷酸酶（6％）活性。SSR改进的根体系结构，具有较高的根长，直径,和音量。苍白杆菌sp.SSR进一步用于设计具有两个充分表征的PS的生物制剂，肠杆菌属。DSM109592和DSM109593，使用四种有机改良剂，生物炭,堆肥,过滤泥浆（FM），和腐殖酸。所有四种载体材料都保持了细菌的足够存活和接种物保质期，场发射扫描电子显微镜分析表明。基于FM的生物制剂最有效，不仅提高了小麦籽粒产量（4-9％），而且提高了种子P（9％）。此外，基于FM的生物制剂提高了土壤有效磷（8.5-11％）和磷酸酶活性（4-5％）。在存在不同的不溶性P源的情况下，PSB溶解之间观察到正相关，和土壤有效磷，土壤磷酸酶活性，种子P含量，和田间接种的小麦品种Faisalabad-2008的谷物产量，当磷酸二铵肥料的施用减少20％时。这项研究首次报道了接种PSB菌株的标记基因表达，并为设计可保持接种动态并延长其保质期的田间规模配方提供了宝贵的基础。在缺磷的土壤条件下，这可能构成小麦可持续种植的阶跃变化。
