Abiotic stresses, especially cold, salinity and drought, are the primary causes of crop loss worldwide. Plant adaptation to environmental stresses is dependent upon the activation of cascades of molecular networks involved in stress perception, signal transduction, and the expression of specific stress-related genes and metabolites. Plants have stress-specific adaptive responses as well as responses which protect the plants from more than one environmental stress. There are multiple stress perception and signaling pathways, some of which are specific, but others may cross-talk at various steps. In this review article, we first expound the general stress signal transduction pathways, and then highlight various aspects of biotic stresses signal transduction networks. On the genetic analysis, many cold induced pathways are activated to protect plants from deleterious effects of cold stress, but till date, most studied pathway is ICE-CBF-COR signaling pathway. The Salt-Overly-Sensitive (SOS) pathway, identified through isolation and study of the sos1, sos2, and sos3 mutants, is essential for maintaining favorable ion ratios in the cytoplasm and for tolerance of salt stress. Both ABA-dependent and -independent signaling pathways appear to be involved in osmotic stress tolerance. ROS play a dual role in the response of plants to abiotic stresses functioning as toxic by-products of stress metabolism, as well as important signal transduction molecules and the ROS signaling networks can control growth, development, and stress response. Finally, we talk about the common regulatory system and cross-talk among biotic stresses, with particular emphasis on the MAPK cascades and the cross-talk between ABA signaling and biotic signaling.

A skin-like gradient-wrinkle rGO film with a hierarchical structure that showed ultrahigh sensitivity and a special motion-direction detection of moving objects.

The purpose of this study was to test the effects of a series of strontium-substituted HA (Sr-HA) ceramics (0, 1, 5, and 10 mol% Sr substitution) on osteoblasts, thereby demonstrating whether strontium incorporation with HA would favor osteoblast metabolism. Rat primary osteoblasts were cultured with culture media containing ions released from the Sr-HA ceramics as they dissolved. MTT test, alkaline phosphatase activity, osteoblast transcription factor gene (cbfa1) expression and Alizarin Red staining were conducted at different time-points. There is no significant difference in cell proliferation between groups. However, compared with HA group, Sr-HA groups presented significant enhancement with regard to ALP activity, cbfa1 mRNA expression, and mineralization nodules. Among Sr-HA groups, 5 and 10% groups showed much better performances in ALP activity, cbfa1 mRNA expression, and mineralization nodules than 1% group, however, no significant difference was found between 5 and 10% groups. This study has demonstrated that Sr incorporation in HA ceramic enhanced osteoblastic cell differentiation and mineralization. However, further detailed studies are needed to understand the mechanistic effects of this Sr incorporation on osteoblastic cells and the optimal percentage of calcium should be substituted with strontium in HA.

Electrical stimulation (ES) therapy has good effects in patients with nervous system injury-related diseases. ES promotes nerve cell regeneration and stimulates Schwann cells to express neurotrophic factors. The incidence of stress urinary incontinence (SUI) among elderly people is increasing. Some studies suggest that damage to the pudendal nerve is closely related to the pathogenesis of SUI. It has also been found that pelvic ES can reduce SUI symptoms in a rat model of SUI caused by pudendal nerve injury. Clinically, pelvic floor electrical stimulation is effective in patients with mild to moderate SUI. These studies indicate that ES may ameliorate damage to the pudendal nerve and thus achieve the goal of SUI treatment, although the mechanism of action of this treatment remains unclear. Therefore, the purpose of the present study was to clarify the relationships among ES, neural cells and Schwann cells at the cellular level. We applied ES to nerve cells at 100 mV/mm or 200 mV/mm for 0, 0.5, 1, or 2 h to investigate changes in nerve cell activity. We then co-cultured the nerve cells with Schwann cells to explore the influence of single-culture and co-culture conditions on the nerve cells. Compared to non-ES, ES of the nerve cells increased their activity. Compared to those in single culture, co-cultured nerve cells exhibited an additional increase in activity. We also found that Schwann cell derived exosomes could promote the activity of nerve cells, with glutamate and calcium ions playing a potential role in this process. These results suggest that the mutual regulation of neural cells and Schwann cells plays an important role in the process by which ES ameliorates neurological function, which may provide a basis for subsequent studies.

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