Melatonin Confers NaCl Tolerance in Withaniacoagulans L. by Maintaining Na+/K+ Homeostasis, Strengthening the Antioxidant Defense System and Modulating Withanolides Synthesis-Related Genes.

As a multifunctional signaling molecule, melatonin (ML) is widely considered to induce the defense mechanism and increase the accumulation of secondary metabolites under abiotic stresses. Here, the effects of different concentrations of ML (100 and 200 µM) on the biochemical and molecular responses of Withania coagulans L. in hydroponic conditions under 200 mM NaCl treatment were evaluated. The results showed that NaCl treatment impaired photosynthetic function and reduced plant growth by decreasing photosynthetic pigments and gas exchange parameters. NaCl stress also induced oxidative stress and membrane lipid damage, disrupting Na+/K+ homeostasis and increasing hydrogen peroxide levels. NaCl toxicity decreased nitrogen (N) assimilation activity in leaves by reducing the activity of enzymes associated with N metabolism. However, adding ML to NaCl-stressed plants improved gas exchange parameters and increased photosynthesis efficiency, resulting in improved plant growth. By enhancing the activity of antioxidant enzymes and reducing hydrogen peroxide levels, ML ameliorated NaCl-induced oxidative stress. By improving N metabolism and restoring Na+/K+ homeostasis in NaCl-stressed plants, ML improved N uptake and plant adaptation to salinity. ML increased the expression of genes responsible for the biosynthesis of withanolides (FPPS, SQS, HMGR, DXS, DXR, and CYP51G1) and, as a result, increased the accumulation of withanolides A and withaferin A in leaves under NaCl stress. Overall, our results indicate the potential of ML to improve plant adaptation under NaCl stress through fundamental changes in plant metabolism. Supplementary Information: The online version contains supplementary material available at 10.1134/S1021443723600125.

Theory of Planned Behavior and Perceived Role Model as Predictors of Nutrition and Physical Activity Behaviors Among College Students in Health-Related Disciplines.

Physical activity (PA) and nutrition behaviors among college students in health-related disciplines are understudied. We used theory of planned behavior (TPB) and role model beliefs (RMB) to predict PA and eating behaviors of college students in health-related programs (nurses, physical education, exercise science, and athletic training). A 26-item survey was administered among the participants. Independent variables included TPB constructs and RMB measured on a 5-point scale. PA was measured by multiplicative scores of students' number of days by the amount of time spent exercising per week. Nutrition behavior was measured using fruits (2½ c-eq/day), vegetables (2½ c-eq/day), dairy (2 c-eq/day), grains (6 oz-eq/day), and proteins (5½ oz-eq/day). Multiple regression analyses were used to predict PA and nutrition behaviors. A total of 271 college health majors (mean age 22.5 ± 4.6 years) participated in the study. The majority (56.8%) of students did not meet the weekly PA guidelines and 43.2% did not meet the recommended dietary guidelines for daily servings of food groups combined. Regression analyses showed that outcome evaluation, behavioral belief, and RMB, were significantly related with student's PA behavior and they accounted for 34%, 8%, and 1% of the variance, respectively (total R2 = 44.7). Outcome evaluation and behavioral beliefs were significantly related with nutritional behavior and they accounted for 13.3%, and 5.3% of the variance respectively (total R2 = 18.6). TPB (outcome evaluation, behavioral belief) and RMB could be used to guide programs in promoting PA and nutrition behavior among college health majors.

Young adults' human papillomavirus-related knowledge: source of medical information matters.

OBJECTIVES: Few studies examine the influence that different sources of medical information has on human papillomavirus (HPV)-related knowledge. We examined the relationship between the primary source of medical information and knowledge about HPV in young adults aged 18-26 years. STUDY DESIGN: This study used cross-sectional data from the Health Information National Trends Survey. METHODS: Respondents (n = 404) self-reported their knowledge about HPV-related diseases and vaccinations and their sources of medical information. Sources of medical information included electronic/print media, family/friends, or a healthcare provider. Bivariate and multivariate analyses were used to examine the association between the source of information and HPV knowledge. RESULTS: Fifty-six percent of respondents used electronic or print media as their primary source of medical information. A greater proportion of Hispanic (40.0%) and black (36.0%) respondents received medical information from their family/friends than white respondents (20.0%). Respondents who received medical information from family/friends had 4.34 (95% confidence interval [CI]: 2.14, 8.79), 4.06 (95% CI: 2.05, 8.04), and 2.35 (95% CI: 1.10, 5.04) times higher odds than those who received information from healthcare providers of not knowing that HPV causes cervical cancer, knowing HPV is a sexually transmitted infection, and hearing about the HPV vaccine, respectively. CONCLUSION: Source of medical information was significantly associated with knowledge of HPV. Receiving medical information from family/friends negatively influenced young adults' HPV knowledge. These findings may guide future interventions to target peer and familial influence on medical decisions.