Microelement strontium and human health: comprehensive analysis of the role in inflammation and non-communicable diseases (NCDs).

Strontium (Sr), a trace element with a long history and a significant presence in the Earth's crust, plays a critical yet often overlooked role in various biological processes affecting human health. This comprehensive review explores the multifaceted implications of Sr, especially in the context of non-communicable diseases (NCDs) such as cardiovascular diseases, osteoporosis, hypertension, and diabetes mellitus. Sr is predominantly acquired through diet and water and has shown promise as a clinical marker for calcium absorption studies. It contributes to the mitigation of several NCDs by inhibiting oxidative stress, showcasing antioxidant properties, and suppressing inflammatory cytokines. The review delves deep into the mechanisms through which Sr interacts with human physiology, emphasizing its uptake, metabolism, and potential to prevent chronic conditions. Despite its apparent benefits in managing bone fractures, hypertension, and diabetes, current research on Sr's role in human health is not exhaustive. The review underscores the need for more comprehensive studies to solidify Sr's beneficial associations and address the gaps in understanding Sr intake and its optimal levels for human health.

Two New Polyphenol Oxidase Genes of Tea Plant (Camellia sinensis) Respond Differentially to the Regurgitant of Tea Geometrid, Ectropis obliqua.

Polyphenol oxidases (PPOs) have been reported to play an important role in protecting plants from attacks by herbivores. Though PPO genes in other plants have been extensively studied, research on PPO genes in the tea plant (Camellia sinensis) is lacking. In particular, which members of the PPO gene family elicit the defense response of the tea plant are as yet unknown. Here, two new PPO genes, CsPPO1 and CsPPO2, both of which had high identity with PPOs from other plants, were obtained from tea leaves. The full length of CsPPO1 contained an open reading frame (ORF) of 1740 bp that encoded a protein of 579 amino acids, while CsPPO2 contained an ORF of 1788 bp that encoded a protein of 595 amino acids. The deduced CsPPO1 and CsPPO2 proteins had calculated molecular masses of 64.6 and 65.9 kDa; the isoelectric points were 6.94 and 6.48, respectively. The expression products of recombinant CsPPO1 and CsPPO2 in Escherichia coli were about 91 and 92 kDa, respectively, but the recombinant proteins existed in the form of an inclusion body. Whereas CsPPO1 is highly expressed in stems, CsPPO2 is highly expressed in roots. Further results showed that the expression of CsPPO1 and CsPPO2 was wound- and Ectropis obliqua-induced, and that regurgitant, unlike treatment with wounding plus deionized water, significantly upregulated the transcriptional expression of CsPPO2 but not of CsPPO1. The difference between regurgitant and wounding indicates that CsPPO2 may play a more meaningful defensive role against E. obliqua than CsPPO1. Meanwhile, we found the active component(s) of the regurgitant elicited by the expression of CsPPO may contain small molecules (under 3-kDa molecular weight). These conclusions advance the understanding of the biological function of two new PPO genes and show that one of these, CsPPO2, may be a promising gene for engineering tea plants that are resistant to E. obliqua.

Prioritizing plant defence over growth through WRKY regulation facilitates infestation by non-target herbivores.

Plants generally respond to herbivore attack by increasing resistance and decreasing growth. This prioritization is achieved through the regulation of phytohormonal signaling networks. However, it remains unknown how this prioritization affects resistance against non-target herbivores. In this study, we identify WRKY70 as a specific herbivore-induced, mitogen-activated protein kinase-regulated rice transcription factor that physically interacts with W-box motives and prioritizes defence over growth by positively regulating jasmonic acid (JA) and negatively regulating gibberellin (GA) biosynthesis upon attack by the chewing herbivore Chilo suppressalis. WRKY70-dependent JA biosynthesis is required for proteinase inhibitor activation and resistance against C. suppressalis. In contrast, WRKY70 induction increases plant susceptibility against the rice brown planthopper Nilaparvata lugens. Experiments with GA-deficient rice lines identify WRKY70-dependent GA signaling as the causal factor in N. lugens susceptibility. Our study shows that prioritizing defence over growth leads to a significant resistance trade-off with important implications for the evolution and agricultural exploitation of plant immunity.