Bacterial motility relying on flagella is characterized by several modes, including swimming, swarming, twitching, and gliding. This motility allows bacteria to adapt remarkably well to hostile environments. More than 50% of bacteria naturally contain flagella, which are crucial for bacterial chemotaxis motility. Chemotaxis can be either positive, where bacteria move towards a chemical source, or negative, known as chemorepulsion, where bacteria move away from the source. Although much is known about the mechanisms driving chemotaxis towards attractants, the molecular mechanisms underlying chemorepulsion remain elusive. Chemotaxis plays an important role in the colonization of the rhizosphere by rhizobacteria. Recently, researchers have systematically studied the identification and recognition mechanisms of chemoattractants. However, the mechanisms underlying chemorepellents remain unclear. Systematically sorting and analyzing research on chemorepellents could significantly enhance our understanding of how these compounds help probiotics evade harmful environments or drive away pathogens.

The rhizosphere microbiome plays a critical role in promoting crop health and productivity. Selenium (Se), a beneficial trace element for plants, not only enhances resistance to both abiotic and biotic stresses but also modulates soil microbial communities. Se biofortification of crops grown in seleniferous soils using selenobacteria represents an eco-friendly and sustainable biotechnological approach. Crops primarily absorb selenium from the soil in its oxidized forms, selenate and selenite, and subsequently convert it into organic Se compounds. However, the role of Se-oxidizing bacteria in soil Se transformation, bioavailability, and plant uptake remains poorly understood. In this review, systematic collection and analysis of research on selenobacteria, including both Se-oxidizing and Se-reducing bacteria, are therefore essential to elucidate their functions in enhancing crop growth and health. These insights can (i) deepen our mechanistic understanding of microbially mediated Se cycling and stress resilience and (ii) offer a novel framework for nanomicrobiome engineering aimed at promoting sustainable food production.

Breast cancer is one of the most common malignant tumors among women, which seriously threatens women’s health. Human epidermal growth factor receptor 2 (HER2)-positive breast cancer, characterized by poor prognosis, is an aggressive phenotype accounting for 15–20% of all kinds of breast cancers. Therefore, it has attracted great interest among researchers in discovering targeted therapy drugs countering HER2, and they have been considered as the pivotal therapeutic regimen for HER2-positive breast cancer patients. Nowadays, large progress has been achieved in HER2-targeted drugs, and this review categorizes them into four types according to the drug action mode, including monoclonal antibodies (mAbs), tyrosine kinase inhibitors (TKIs), antibody-drug conjugates (ADCs), and bispecific antibodies (bsAbs). The progress of HER2-targeted drugs reflects the discovery of drug targets, the screening of drug compounds, and the modification of antibodies, which offer diverse medical options and better therapeutic benefits for individual patients. In detail, we focus on the indication, administration, efficacy, strengths, and challenges of HER2-targeted drugs, concerning approved drugs and clinical trials. This review aims to provide significant references for the targeted therapeutic regimen and a more precise treatment strategy for HER2-positive breast cancer.