Aluminum (Al) toxicity is a major environmental stress that inhibits plant growth and development. There has been impressive progress in recent years that has greatly increased our understanding of the nature of Al toxicity and its mechanisms of tolerance. This review describes the transcription factors (TFs) and plant hormones involved in the adaptation to Al stress. In particular, it discusses strategies to confer plant resistance to Al stress, such as transgenic breeding, as well as small molecules and plant growth-promoting rhizobacteria (PGPRs) to alleviate Al toxicity. This paper provides a theoretical basis for the enhancement of plant production in acidic soils.
Brassinosteroids (BRs) are essential steroid hormones that coordinate plant growth, development and adaptation to changing environments. Although BR signaling has long been viewed primarily as a phosphorylation-dependent pathway, increasing evidence shows that ubiquitination provides an additional regulatory layer that shapes the abundance, activity, subcellular distribution and turnover of key signaling components. Ubiquitin-mediated regulation operates at multiple points in the BR pathway, including receptor homeostasis at the plasma membrane, turnover of GSK3-like kinases, and stability control of the transcription factors BES1/BZR1. These processes determine not only the strength and duration of BR signaling but also its coordination with other hormonal and stress-response pathways. In this review, we discuss recent advances in ubiquitin-mediated regulation of BR signaling, focusing on receptor-level control, proteolytic regulation of core signaling components, and modulation of transcriptional outputs. We also highlight emerging links between ubiquitination, selective autophagy, deubiquitination and BR-associated stress responses, and outline key questions concerning ubiquitin chain specificity, substrate recognition and conservation of these regulatory modules in crops. Defining how ubiquitination fine-tunes BR signaling will deepen our understanding of plant steroid hormone regulation and may provide new strategies for optimizing crop architecture, productivity and stress resilience.
Brassinosteroids (BRs) are essential steroid hormones that coordinate plant growth, development and adaptation to changing environments. Although BR signaling has long been viewed primarily as a phosphorylation-dependent pathway, increasing evidence shows that ubiquitination provides an additional regulatory layer that shapes the abundance, activity, subcellular distribution and turnover of key signaling components. Ubiquitin-mediated regulation operates at multiple points in the BR pathway, including receptor homeostasis at the plasma membrane, turnover of GSK3-like kinases, and stability control of the transcription factors BES1/BZR1. These processes determine not only the strength and duration of BR signaling but also its coordination with other hormonal and stress-response pathways. In this review, we discuss recent advances in ubiquitin-mediated regulation of BR signaling, focusing on receptor-level control, proteolytic regulation of core signaling components, and modulation of transcriptional outputs. We also highlight emerging links between ubiquitination, selective autophagy, deubiquitination and BR-associated stress responses and outline key questions concerning ubiquitin chain specificity, substrate recognition and conservation of these regulatory modules in crops. Defining how ubiquitination fine-tunes BR signaling will deepen our understanding of plant steroid hormone regulation and may provide new strategies for optimizing crop architecture, productivity, and stress resilience.