Advances in protein ubiquitination in response to low phosphorus stress in plants

Phosphorus (P) serves as important substrates of many key macromolecules, and plays important roles in many physiological regulatory reactions in plants. Inefficient phosphorous nutrition has been one of the main factors limiting crop yield and quality. In the long-term evolution process, plants have evolved a series of mechanisms to adapt to low P stress. Protein ubiquitination has been found as an important path in plant responses to low P stress recently. In this paper, the roles and mechanisms of ubiquitination of key proteins in response to P deficiency in plants were summarized, and the recent advances on plant ubiquitination approach to cope with P starvation were reviewed. Protein ubiquitination can change the activity, stability and subcellular localization of the target proteins. Ubiquitin, enzyme and target protein are three main components involved in ubiquitin modification. Ubiquitin is composed of 76 amino acids, which are linked to the target protein in a step-by-step conjugate cascade, forming an ubiquitin protein complex, which is transported to 26S proteasome for degradation in vivo to regulate many different physiological processes. Protein ubiquitin modification can promote or inhibit the uptake of P in soils, and its transport to the shoot by changing the root architecture through hormone signaling pathway, affecting the activity and localization of phosphate transporters and related transcription factors, thus regulating P homeostasis. In the end, the research focus of protein ubiquitination in response to low P stress in future is prospected.