Effects of topping and non-topping on growth-regulating hormones of flue-cured tobacco (Nicotiana tabacum L.)-a proteomic analysis.

Introduction: Until now, the mechanism underlying the impact of topping on hormone regulation in tobacco plants remains unclear, and most studies investigating the hormone signaling pathways in plants rely on genes or transcriptional pathways. Methods: This study examines the regulatory mechanisms of hormones in the roots and leaves of tobacco plants with and without topping at the protein level. Results: The results demonstrate that, compared with non-topped plants, topping leads to a decrease in the levels of IAA (auxin), ABA (abscisic acid), and GA (gibberellin) hormones in the leaves, whereas the content of the JA (jasmonic acid) hormone increases. Furthermore, in the roots, topping results in an increase in the levels of IAA, ABA, and JA hormones, along with a decrease in GA content. In the leaves, a total of 258 significantly different proteins were identified before and after topping, with 128 proteins upregulated and 130 proteins downregulated. In the roots, there were 439 proteins with significantly different quantities before and after topping, consisting of 211 upregulated proteins and 228 downregulated proteins. Notably, these proteins were closely associated with the metabolic and biosynthetic pathways of secondary metabolites, as indicated by functional categorization. Conclusions: When integrating the hormone changes and the proteomics results, it is evident that topping leads to increased metabolic activity and enhanced hormone synthesis in the root system. This research provides a theoretical foundation for further investigations into the regulation and signaling mechanisms of hormones at the protein level before and after topping in plants.

Trait Acceptance Buffers Aggressive Tendency by the Regulation of Anger during Social Exclusion.

Social exclusion has led to increased negative emotions and aggressive behaviors, two outcomes that are correlated with each other. Thus, the down-regulation of negative emotions appears to play a crucial role in reducing the tendency for aggressive behavior. However, this assumption has not yet been tested. To this end, a total of 397 undergraduates reported their aggressive tendencies, state emotions and trait acceptance by completing corresponding questionnaires, and a recall paradigm was used to induce experiences of social exclusion. The results showed that in the context of social exclusion, (1) trait acceptance was negatively correlated with negative emotions and aggressive tendency but was positively correlated with positive emotions; (2) negative emotions, rather than positive emotions, were positively correlated with aggressive tendency; (3) increased trait acceptance buffered the experience of anger, which is, in turn, related to reduced aggressive tendency; (4) trait acceptance also downregulated the feeling of sadness, which is, however, related to increased aggression; (5) the mediator of sadness was smaller in effect size than that of anger. Taken together, these results suggest that negative emotions are associated with aggression in the context of social exclusion, and the habitual use of an acceptance strategy was conductive to decreasing aggressive tendencies by decreasing anger.