Author Correction: Root growth in light of changing magnesium distribution and transport between source and sink tissues in potato (Solanum tuberosum L.).

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Physical Activity and Body Composition Are Associated With Severity and Risk of Depression, and Serum Lipids.

BACKGROUND: Physical activity and a healthy body composition are said to reduce the risk of major depressive disorder. Nonetheless, deeper insight is needed into which specific forms of physical activity (and their relation to body composition) are effective in improving and preventing depressive symptoms. METHODS: We compared different self-reported physical activities of the Global Physical Activity Questionnaire and body composition measures between patients with a current major depressive episode (MDE; N = 130) and healthy control subjects (N = 61). These parameters were also tested for correlations with depression severity and serum lipid levels in patients and controls. RESULTS: Patients with a current MDE reported significantly fewer hours spent on total physical activity, walking or bicycling for travel, and vigorous-intensity activities at leisure than healthy control subjects. More time spent on vigorous-intensity activities at work, less time spent on walking or bicycling for travel, higher body fat mass, and lower body muscle mass correlated significantly with stronger depression severity. Physical activity and body measures correlated significantly with serum lipid levels. LIMITATIONS: Self-reports of physical activity, only short-term follow-up of 20 days, cross-sectional study design without examination of causal role of exercise. CONCLUSIONS: More time spent on traveling by foot or by bike is especially associated with a lower risk of and milder depression. These results highlight the differential role of physical activity in depression.

Root growth in light of changing magnesium distribution and transport between source and sink tissues in potato (Solanum tuberosum L.).

This study depicts relations between magnesium (Mg) transport and re-translocation, photoassimilate partitioning, cation and ion concentrations, and finally root growth of potato under different Mg supplies. Potato plants were grown in a hydroponic culture system under different Mg regimes while investigating Mg concentrations, the expression of various Mg transporters, soluble sugars, and cations and anions in source and sink organs at different growth stages. Reports from literature about the impact of Mg deficiency on root growth are inconsistent. As Mg is known to be a phloem mobile nutrient, it is expected to be re-translocated under restricted availability of Mg from source to sink organs. Thus, we assume that plants can tolerate a slight Mg restriction without severe root growth reduction. However, under severe Mg deficiency, the process of Mg re-translocation is hampered, resulting in an impaired photoassimilate partitioning, and finally root growth. This might also explain the findings of studies claiming that Mg deficiency does not impair root growth as plants of these studies likely only suffered a slight Mg restriction. Finally, this study gives indications that an interruption of the process of Mg-re-translocation in early plant growth could be an indicator for growth reductions of the plant at a later growth stage.

LDL cholesterol relates to depression, its severity, and the prospective course.

BACKGROUND: Major depressive disorder (MDD) is a highly prevalent and burdening mental illness. Approximately 30% of the major depressive episodes (MDE) are classified as therapy-refractory. Further knowledge of the pathophysiological mechanisms underlying MDD and predictive biomarkers are needed to improve treatment options. METHODS: Serum lipid levels were compared between patients with a current MDE (n = 130) or remitted MDD (n = 39) and healthy control subjects (n = 61) and associated with the severity (17-item Hamilton Depression Rating Scale [HAMD] scores) and the prospective course of depression (direct follow-up of at median 20 days post-inclusion). RESULTS: We found higher levels of LDL cholesterol (152.5 vs. 134.0 mg/dl, U = 3021, P = 0.008) and LDL/HDL ratio (2.82 vs. 2.21, U = 2912, P = 0.003) in patients with a current MDE than in healthy control subjects. In patients with a current MDE, higher HAMD scores correlated also with higher values of triglycerides (ρ = 0.213, P = 0.015), total cholesterol (ρ = 0.199, P = 0.023), LDL cholesterol (ρ = 0.224, P = 0.010), and LDL/HDL ratio (ρ = 0.196, P = 0.026). Moreover, higher total cholesterol (ρ = -0.233, P = 0.010), LDL cholesterol (ρ = -0.235, P = 0.010), and LDL/HDL ratio (ρ = -0.199, P = 0.029) were associated with a stronger decline in HAMD score between study inclusion and direct follow-up. LIMITATIONS: We employed an associational study design, performed only a short-term follow-up, and excluded suicidal study subjects. CONCLUSIONS: Serum lipid levels are associated with depression per se, the depression severity, and the prospective 3-week course. These observations build the basis for future investigations on individualized lipid metabolism-related treatment strategies in depressed patients.