MiPEPs and cPEPs as tools to monitor plant gene expression and develop alternative strategies in agriculture.

In order to develop a sustainable agriculture respecting the environment and to reduce chemical inputs, a new strategy has emerged in recent years, based on the use of products targeting plants' natural defense and growth mechanisms. In this context, a few years ago we demonstrated the existence in plants of regulatory peptides called miPEPs for "microRNA-encoded peptides". MicroRNAs (miRNAs) are small RNAs that down-regulate the expression of numerous genes in eukaryotes.

The Essentials on microRNA-Encoded Peptides from Plants to Animals.

Primary transcripts of microRNAs (pri-miRNAs) were initially defined as long non-coding RNAs that host miRNAs further processed by the microRNA processor complex. A few years ago, however, it was discovered in plants that pri-miRNAs actually contain functional open reading frames (sORFs) that translate into small peptides called miPEPs, for microRNA-encoded peptides. Initially detected in and , recent studies have revealed the presence of miPEPs in other pri-miRNAs as well as in other species ranging from various plant species to animals.

Complementary peptides represent a credible alternative to agrochemicals by activating translation of targeted proteins.

The current agriculture main challenge is to maintain food production while facing multiple threats such as increasing world population, temperature increase, lack of agrochemicals due to health issues and uprising of weeds resistant to herbicides. Developing novel, alternative, and safe methods is hence of paramount importance. Here, we show that complementary peptides (cPEPs) from any gene can be designed to target specifically plant coding genes.