A switch in time shapes plant organ growth
DAR2 cleavage of TMK1-EGFP relocates it from the plasma membrane to the nucleus of Arabidopsis root protoplasts. (AH) Confocal images of dar2-1 root protoplasts transformed with TMK1-EGFP, histone HT2B-mCherry, and cleavage mutants with or without DAR2. HT2B-mCherry marks the nucleus. Colocation of TMK1-EGFP and HT2B-mCherry shows as yellow fluorescence. (Scale bars: 5 µm.) (I) Ratios of nuclear-localized/total protoplast EGFP in different TMK1-EGFP cleavage mutants. n = 20 protoplasts from each of three independent experiments. All were compared to TMK-EGFP levels without 3HA-DAR2, and significant differences are indicated as *P < 0.05. Credit: Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2205757119

The Chinese Academy of Sciences and the John Innes Centre collaborated to identify a switch that establishes differential cell growth.

The growth regulator auxin stimulates cell growth. The cell wall has properties that help cell growth. There is an opposite growth-retarding effect in the cell nucleus caused by the reduction of auxin-mediated genes.

These seemingly opposed functions are carried out in different parts of the cell by the same person. This involves the transfer of part of the cleaved proteins from the cell surface to the nucleus. Technical challenges have made it hard to identify the proteins involved in this process.

The members of the peptidases are involved. Growth responses and shaping organ growth can be achieved with the help of theseidases. In the demonstration, the information flow from the cell surface to the nucleus is shown to be altered. Defining these processes helps us understand plant growth.

Dr. Gu, a research assistant at the John Innes Centre, says that their work proved that the DA1 family peptidases function on hormones. A way to improve crop seed emergence could be offered by the findings.

There is a publication in the National Academy of Sciences about the modification of transmembrane kinase 1 nuclear localization by peptidases.

More information: Benguo Gu et al, Modulation of receptor-like transmembrane kinase 1 nuclear localization by DA1 peptidases in Arabidopsis, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2205757119 Journal information: Proceedings of the National Academy of Sciences