Benzoxazinoids in Root Exudates of Maize Attract Pseudomonas putida to the Rhizosphere

Benzoxazinoids, such as 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA), are secondary metabolites in grasses. In addition to their function in plant defence against pests and diseases above-ground, benzoxazinoids (BXs) have also been implicated in defence below-ground, where they can exert allelochemical or antimicrobial activities. We have studied the impact of BXs on the interaction between maize and Pseudomonas putida KT2440, a competitive coloniser of the maize rhizosphere with plant-beneficial traits. Chromatographic analyses revealed that DIMBOA is the main BX compound in root exudates of maize. In vitro analysis of DIMBOA stability indicated that KT2440 tolerance of DIMBOA is based on metabolism-dependent breakdown of this BX compound. Transcriptome analysis of DIMBOA-exposed P. putida identified increased transcription of genes controlling benzoate catabolism and chemotaxis. Chemotaxis assays confirmed motility of P. putida towards DIMBOA. Moreover, colonisation essays in soil with Green Fluorescent Protein (GFP)-expressing P. putida showed that DIMBOA-producing roots of wild-type maize attract significantly higher numbers of P. putida cells than roots of the DIMBOA-deficient bx1 mutant. Our results demonstrate a central role for DIMBOA as a below-ground semiochemical for recruitment of plant-beneficial rhizobacteria during the relatively young and vulnerable growth stages of maize

Characterization of the yehUT Two-Component Regulatory System of Salmonella enterica Serovar Typhi and Typhimurium

10.1371/journal.pone.0084567PLoS ONE812-POLN

Depression in athletes: Prevalence and risk factors

Depression affects an estimated 6.7% of today\u27s adult population in a 12-month period. The prevalence rates for certain age groups, such as young adults and older adults, are higher. There are approximately 400,000 National Collegiate Athletic Association student athletes competing each year and 5 to 7 million high school student athletes involved in competitive interscholastic sports. Given such a high prevalence rate in certain age groups and a large denominator pool of athletes, past notions that athletes are devoid of mental health issues have come under scrutiny by sports medicine providers. Initial data suggest that athletes are far from immune to depression. The purpose of this article was to review the current research on athletes and depression; particularly this article will provide an overview of studies, which have investigated the rate of depression among athletes, and discuss relevant risk factors, which may contribute to depression among athletes

The routledge handbook of clinical sport psychology

Clinical sport psychology is a rapidly growing field that brings together research and clinical interventions from both clinical psychology and sport and performance psychology. Complementary to sports medicine and clinical sport psychiatry, clinical sport psychology addresses the mental health needs and psychological well-being of athletes, coaches, and other members of the sport community. It offers scientifically informed conceptualizations of psychological distress as it manifests in sport settings, as well as empirically supported clinical interventions tailored to the needs of sport populations. This volume addresses the latest research findings regarding mental health among athletes and other sport professionals, including epidemiological research concerning depression, anxiety, eating disorders, and conduct and interpersonal problems. In addition, it explores the unique etiology of mental health problems among athletes, including psychological sequelae of injury and trauma, as well as concise practice guidelines for conceptualizing and treating psychological distress in sport populations. Strategies for thorough yet efficient psychological assessment of athletes, coaches, and other sport professionals are also provided. A compendium of relevant empirical research and clinical best practices for assessment and treatment, this handbook charts the course that clinical sport psychology has taken since its inception as a distinct clinical specialty and highlights future directions for this rapidly growing practice domain. It offers essential reading for psychologists and other mental health professionals who provide clinical services in sport and performance settings