2026-04-18T07:58:38Zhttps://recercat.cat/oai/request

oai:recercat.cat:10230/469112025-12-24T08:39:49Zcom_2072_6col_2072_452952

00925njm 22002777a 4500 dc Hong, Shin-Young author Sun, Bin author Straub, Daniel author Blaakmeer, Anko author Mineri, Lorenzo author Koch, Jonas author Brinch-Pedersen, Henrik author Holme, Inger B. author Burow, Meike author Lyngs Jørgensen, Hans Jørgen author Albà Soler, Mar author Wenkel, Stephan author 2021-03-24T06:57:56Z 2021-03-24T06:57:56Z 2020 MicroProteins are small, often single-domain proteins that are sequence-related to larger, often multidomain proteins. Here, we used a combination of comparative genomics and heterologous synthetic misexpression to isolate functional cereal microProtein regulators. Our approach identified LITTLE NINJA (LNJ), a microProtein that acts as a modulator of jasmonic acid (JA) signaling. Ectopic expression of LNJ in Arabidopsis resulted in stunted plants that resembled the decuple JAZ (jazD) mutant. In fact, comparing the transcriptomes of transgenic LNJ overexpressor plants and jazD revealed a large overlap of deregulated genes, suggesting that ectopic LNJ expression altered JA signaling. Transgenic Brachypodium plants with elevated LNJ expression levels showed deregulation of JA signaling as well and displayed reduced growth and enhanced production of side shoots (tiller). This tillering effect was transferable between grass species, and overexpression of LNJ in barley and rice caused similar traits. We used a clustered regularly interspaced short palindromic repeats (CRISPR) approach and created a LNJ-like protein in Arabidopsis by deleting parts of the coding sentence of the AFP2 gene that encodes a NINJA-domain protein. These afp2-crispr mutants were also stunted in size and resembled jazD Thus, similar genome-engineering approaches can be exploited as a future tool to create LNJ proteins and produce cereals with altered architectures. Work in the laboratory was funded by the European Research Council (ERC-StG miPDesign, 336295), the Independent Research Fund Denmark (DFF-FNU, Adaptogenomics), the NovoNordisk Foundation (NNF18OC0034226), and start-up funding of Copenhagen Plant Science Centre through the University of Copenhagen. We thank the anonymous reviewers from a previous submission, Hans Thordal-Christensen, Gregg Howe, and Michael Broberg Palmgren for critically reading and improving our manuscript. Branching Jasmonic acid microProteins Heterologous microProtein expression identifies LITTLE NINJA, a dominant regulator of jasmonic acid signaling