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Purpose: There is robust evidence indicating the adverse association between childhood abuse and depressive symptoms. However, the ways in which childhood physical abuse is indirectly associated with adulthood depressive symptoms by alexithymia and moral disengagement remain poorly understood, particularly in the context of China. The present study aims to investigate how childhood physical abuse may be associated with depressive symptoms via the serial mediation effects of alexithymia and moral disengagement among college students in China. Methods: A total of 686 college students (female: 53.2%) aged from 17 to 28 years old (M = 21.33; SD = 2.53) were recruited from mainland China to participate in an online survey assessing the variables of interest. Structural equation modeling and multiple group analysis were performed using Mplus 7.0 to investigate the hypothesized model. Results: College students' experiences with childhood physical abuse was significantly associated with their depressive symptoms. This relationship was partially mediated by alexithymia and then by moral disengagement. Meanwhile, alexithymia and moral disengagement had a chain mediating effect on childhood physical abuse and depressive symptoms. Furthermore, multigroup analysis revealed that the association between alexithymia and depressive symptoms was stronger among rural students compared to urban students. Furthermore, the mediation model involving moral disengagement applies exclusively to rural students. Conclusion: Alexithymia and moral disengagement exerted serial mediating effect on the association between childhood physical abuse and depressive symptoms. This pattern was particularly pronounced among rural students. These findings underscore the importance of addressing both childhood adversity and maladaptive cognitive processes in the prevention and treatment of depression.
RESUMEN
The B-type cyclin gene, CycB2, serves as a negative regulator of glandular trichome initiation. Through targeted knockout of NtCycB2 in Nicotiana tabacum cv. K326 using the CRISPR/Cas9 system, we created a variety, HK326, which exhibits significantly increased density and larger glandular heads of long glandular trichomes. Under Cd-stress, HK326 exhibited enhanced Cd tolerance, as demonstrated by a robust root system, strengthened cell membrane stability, and higher photosynthetic parameters. HK326 exhibited enhanced Cd-stress tolerance due to a strong excretion capacity of long glandular trichomes by forming calcium oxalate crystals. Cd mainly accumulated in tobacco shoots rather than remained in roots. Specifically, Cd levels of the HK326 shoot surface were nearly two-fold of those of K326, resulting in less Cd internally in the roots and shoots. Gene expression patterns revealed 11 Cd transporter genes that were upregulated after Cd-stress in shoots, roots, and trichomes. Among them, the NtHMA2 gene encoding heavy metal ATPases and involved in the transport of divalent heavy metal cations was expressed consistently and significantly higher in HK326 than K326, both before and after Cd-stress. NtHMA2 expression was strong in trichomes, moderate in shoots, while weak in roots. The results indicate that NtHMA2 may be involved in Cd excretion from glandular trichomes. Our findings suggest HK326 may be an appropriate candidate plant for Cd-stress tolerance.