Plant growth promoting endophyte promotes cadmium accumulation in Solanum nigrum L. by regulating plant homeostasis.

The homeostasis regulating mechanism of endophyte enhancing cadmium (Cd) extraction by hyperaccumulator is poorly understood. Here, an endophyte strain E3 that belonged to Pseudomonas was screened from Cd hyperaccumulator Solanum nigrum L., which significantly improved the Cd phytoextraction efficiency of S. nigrum by 40.26%. The content and translocation factor of nutrient elements indicated that endophyte might regulate Cd accumulation by affecting the uptake and transport of magnesium and iron in S. nigrum. Gene transcriptional expression profile further revealed that SnMGT, SnIRT1, and SnIRT2, etc., were the key genes involved in the regulation of S. nigrum elements uptake by endophyte. However, changes in elemental homeostasis did not negatively affect plant growth. Endophyte inoculation promoted plant growth by fortifying photosynthesis as well as recruiting specific bacteria in S. nigrum endosphere, e.g., Pseudonocardiaceae, Halomonas. Notably, PICRUSt2 analysis and biochemical characterization jointly suggested that endophyte regulated starch degradation in S. nigrum leaves to maintain photosynthetic balance. Our results demonstrated that microecological characteristics of hyperaccumulator could be reshaped by endophyte, also the homeostasis regulation in endophyte enhanced hyperaccumulator Cd phytoextraction was significant.

Three-Column Classification for Acetabular Fractures: Introduction and Reproducibility Assessment.

BACKGROUND: The Judet-Letournel classification has been widely used to diagnose acetabular fractures since it was proposed. However, there has been growing evidence of incompleteness and comprehension difficulty in this classification, which may adversely affect its clinical use. The purposes of this study were to introduce a novel 3-column classification system for acetabular fractures and to evaluate its reliability and reproducibility. METHODS: A total of 1,028 patients with acetabular fractures, who had undergone surgical treatment from June 2011 to January 2017 in 7 level-I trauma centers, were recruited into this study. Preoperative radiographs and computed tomographic (CT) scans were conducted for each patient. To evaluate the reproducibility of the 3-column classification system for acetabular fractures, the interobserver and intraobserver reliability (kappa coefficient, κ) of this classification system compared with those of the Judet-Letournel classification system was investigated by 4 observers. RESULTS: A total of 209 patients (20.33%) could not be classified by the Judet-Letournel classification, and 3 cases (0.29%) could not be classified by the novel 3-column classification. The mean κ value of the interobserver reliability for the Judet-Letournel classification was 0.591 (range, 0.508 to 0.681), indicating moderate agreement, whereas the mean κ value was 0.735 (range, 0.594 to 0.930), indicating substantial agreement, when using the 3-column classification. The mean κ value for the intraobserver reliability was 0.751 (range, 0.708 to 0.793) for the Judet-Letournel classification and 0.909 (range, 0.792 to 0.957) for the 3-column classification. CONCLUSIONS: The 3-column classification, based on the anatomic character of the acetabulum, showed higher interobserver and intraobserver reliability than the Judet-Letournel classification. Additionally, certain fracture patterns in the 3-column classification scheme generally correlated with surgical approaches. This novel classification system may be used as a supplement to the traditional Judet-Letournel classification system. CLINICAL RELEVANCE: The 3-column concept of the acetabulum proposed in this study is helpful to master acetabular fractures for less experienced surgeons. The novel classification system could assist with acetabular fracture diagnosis and the choice of surgical approaches.