Guo-Qiang Wu

C-reactive protein (CRP) is a crucial biomarker of inflammation and a primary pattern recognition molecule of the innate immune system. It is predominantly synthesized by hepatocytes and subsequently released into the circulation. The concentration of CRP in plasma can increase significantly, sometimes by up to a thousand-fold, in the presence of infection, inflammation, or tissue damage, making it a widely used clinical indicator of inflammatory status. The distinctive structure of pentameric CRP (pCRP), coupled with the specific functions of its recognition face (B-face) and effector face (A-face) as well as its calcium-dependent ligand recognition, dictates its structural and functional characteristics. This review presents a thorough analysis of the structure and functional surfaces of CRP, focusing on the dual regulatory role of calcium ions (Ca ²⁺ ) in maintaining structural stability and facilitating ligand recognition. It further examines the historical and mechanistic basis of CRP conformational conversion, emphasizing the distinction between Ca ²⁺ depletion-induced destabilization and physiologically relevant membrane-associated remodeling that can occur in the continued presence of Ca ²⁺ . The present review explores the interaction mechanisms of CRP with its ligands, as well as the influence of the microenvironment on CRP’s conformational dynamics and functional diversity. This review could provide new prospects for designing targeted drugs according to the structural characteristics of CRP.

Calcium-dependent protein kinase (CDPK) is a type of Ca²⁺- sensitive Ser/Thr protein kinase that plays a role in plant growth, development, and response to stress. However, the function of the CDPK gene family in sugar beet (Beta vulgaris L.) is still unknown. In this study, a total of 16 BvCDPK genes in sugar beet were firstly identified by bioinformatics techniques, and they were unevenly distributed across seven chromosomes. The BvCDPK genes were divided into four clusters (I–IV) by phylogenetic analysis, and members of the same family were found to have similar protein motifs and gene structures. Expression profiling under salt stress via qRT-PCR showed that most BvCDPKs were up-regulated, with BvCDPK8 consistently induced in both roots and leaves. Transgenic Arabidopsis thaliana plants overexpressing BvCDPK8 exhibited significantly improved growth under salt stress, accompanied by increased levels of proline, soluble sugars, and total chlorophyll, enhanced activities of antioxidant enzymes such as catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), and marked reduction in malondialdehyde (MDA) content. Furthermore, the expression levels of stress-responsive genes (AtNCED3, AtSOS1, and AtP5CS) were significantly up-regulated in transgenic plants, with AtNCED3 expression in the OE4 line being 3.05-fold higher than in wild-type (WT) plants under 100 mM NaCl. Together, these results demonstrated that BvCDPK8 confers enhanced salt tolerance in A. thaliana, providing a solid foundation for further investigation into its molecular mechanisms.

The sucrose non-fermenting 1-related protein kinase 2 (SnRK2) family of protein kinases plays a crucial role in plant salt stress tolerance. To investigate the function of the BvSnRK2.1 gene in the response to salt stress in sugar beet ( Beta vulgaris L.), the full-length coding sequence (CDS) of BvSnRK2.1 was cloned, and the transgenic tobacco lines overexpressing BvSnRK2.1 were generated. According to the findings, transgenic tobacco lines with overexpression of BvSnRK2.1 gene from sugar beet showed improved root system development, increased levels of proline, sucrose, soluble protein, total soluble sugars and chlorophyll, increased activities of antioxidant enzymes (e.g., peroxidase, catalase and superoxide dismutase) and improved photosynthetic efficiency in saline conditions. Additionally, genes related to proline synthesis ( NbP5CR ), ion transport ( NbSOS1 , NbNHX , and NbAKT ), and reactive oxygen species scavenging (e.g., NbCAT , NbSOD , and NbPOD ) were more highly expressed in tobacco plants overexpressing BvSnRK2.1 . In short, BvSnRK2.1 coordinated several defense mechanisms, such as ion homeostasis, osmoregulation and antioxidant, to greatly improve plant response to salt stress.

Soil properties affect plant growth and cause variation in leaf functional traits. Lycium ruthenicum Murray is one of the desert dominant shrubs and halophytes in the lower reaches of Heihe River, Northwest China. We analyzed the trade-off relationships of 14 leaf functional traits of eight L. ruthenicum populations growing at varying distances from the river and discussed the effects that soil properties have on leaf functional traits. The results showed that: Lower leaf nitrogen (N) content indicated that L.ruthenicum was located at the slow investment–return axis of the species resource utilization graph. Compared with non-saline and very slightly saline habitats, populations of slightly saline habitats showed a higher carbon to nitrogen ratio (C:N). Redundancy analysis (RDA) revealed a relatively strong relationship between leaf functional traits and soil properties, the first RDA axis accounted for 70.99 and 71.09% of the variation in 0–40 and 40–80 cm of soil properties. Relative importance analysis found that in the 0–40 cm soil layer, leaf traits variations were mainly influenced by soil moisture (SWC), HCO₃⁻ and CO₃²⁻ ions content, while leaf traits variations in the 40–80 cm soil layer were mainly influenced by HCO₃⁻ and SO₄²⁻. L.ruthenicum has a foliar resource acquisition method and a resource conservation trade-off with a flexible life history strategy in habitats with drought and salinity stress. In the shallow soil layers, water affects leaf traits variation greater than salt, and in both shallow and deep soil layers, HCO₃⁻ plays a dominant role on leaf traits. This study provides insights into the adversity adaptation strategies of desert plants and the conservation and restoration of arid-saline ecosystems.