Non-conventional peptides in plants: From gene regulation to crop improvement

Conventional peptides (CPs) and non-conventional peptides (NCPs) are generated from small open reading frames, but most CPs are derived from large precursors. NCPs, which are derived from sequences other than conventional open reading frames or annotated coding sequences regions, function in plant development and adaptation to stresses. Ribosome profiling, a technique for studying translational regulation, can be used to identify NCPs. Another new technique, peptidogenomics, which integrates mass spectrometry and genomics, is becoming more widely used for identifying plant NCPs. In recent years, numerous studies have investigated the roles in monocots and dicots of miRNA-derived peptides and upstream open reading frames, which have potential for improving agronomic traits. Investigating the biological functions of NCPs will advance molecular plant breeding by identifying regulators of plant growth and development. We present an overview of NCP identification methods and recent findings about NCP biological functions.