Agriculture Reference
In-Depth Information
Chapter 7
Role of Autophagy in Plant Nutrient
Deficiency
Milagros Collados Rodr
´
guez, Katarzyna Zientara-Rytter,
and Agnieszka Sirko
Abstract One of the environmental stresses frequently encountered by plants is
nutrient deficiency. Therefore, reuse of valuable cellular nutrients is an important
trait in nutrient use efficiency (NUE). High NUE is a desired trait in plants at all
developmental steps to reach maximum potentials with minimum inputs. Two
highly conserved evolutionary mechanisms are responsible for protein turnover at
the cellular level, the ubiquitin-proteasome system (UPS) and the autophagy path-
way. Generally, UPS recycles short-lived regulatory proteins while autophagy
recycles long-lived proteins, protein aggregates or organelles. The proteins,
which are destined for degradation, are marked by a special polypeptide tag,
ubiquitin. The features of this tag, as well as activity of ubiquitinating and deubiqui-
tinating enzymes, are determinants that allocate the protein into one or the other
degradation systems. Apart from the common subset of over 30 proteins required
for the “core autophagy”, there exist selective autophagy cargo receptors. These
proteins perform the quality control function by recognizing ubiquitinated cargoes
(ready for degradation) and linking them to the autophagy machinery. Adequate
knowledge of the processes of selective autophagy will be beneficial for agricul-
tural production and the environment by delivering the methods and means for
obtaining crops with improved NUE, higher yield and better stress tolerance.
Keywords NUE (nutrient use efficiency) • Autophagy • UPS (ubiquitin
proteasome system) • Nutrient deficiency • Protein turnover • Protein homeostasis
• PCD (programmed cell death)
