NBR1-Mediated Selective Autophagy in Plant Development and Stress Responses

Autophagy is a conserved degradation pathway essential for cellular homeostasis in plants. Selective autophagy confers cargo specificity through receptors, among which NEIGHBOR OF BRCA1 GENE1 (NBR1) is one of the best-characterized. NBR1 mediates the selective turnover of ubiquitinated or stress-damaged cargoes, including protein aggregates and damaged organelles, by linking them to ATG8-decorated autophagosomes via its AIM and UBA domains. This process supports proteostasis, plant development, and adaptation to abiotic stresses, including heat, drought, chilling, salinity, and heavy metals, as well as biotic stresses from bacteria, fungi, viruses, and oomycetes. In this review, we summarize current advances in understanding NBR1 structure, evolutionary conservation, and cargo recognition mechanisms, and highlight its interplay with phytohormone signaling and the ubiquitin–proteasome system (UPS) in shaping plant growth and stress resilience.