Plant Growth Regulation - Clonostachys rosea f. catenulate is a well-documented fungus, with extensive research reported on its antagonistic activity and mechanisms as a biocontrol. However, the...

Nitrogen is a major limiting nutrient for plant growth and a central driver of fertilizer use in agriculture. In many agricultural soils, nitrate is the main form of available nitrogen, but it is highly mobile and unevenly distributed, forcing plants to continuously adjust root growth to local supply. Legumes add an extra layer of complexity because they can also obtain ammonium through symbiotic nitrogen fixation in root nodules, which are carbon-expensive organs that must be regulated according to both external nitrate levels and internal nitrogen status. This review compares nitrogen signalling in the non-legume Arabidopsis thaliana and the model legume Medicago truncatula. Our aim is to understand how conserved pathways have been rewired to support these different nitrogen acquisition strategies. We focus on three core modules: CLE–CLV1/SUNN signalling, the NIN–NLP transcriptional module and the miR2111–TML pathway. In Arabidopsis, CLE–CLV1 acts mainly as a local low-nitrogen checkpoint that restricts lateral root emergence in nitrate-poor zones, while NLP7 integrates nitrate availability with root architectural responses. In Medicago, orthologous components have been recruited into the autoregulation of nodulation (AON) pathway, where nitrate-induced CLE peptides, NIN–NLP interactions and the systemic miR2111–TML module together integrate nitrate supply and rhizobial infection to coordinate nodulation with whole-plant nitrogen status and carbon cost. Within this network, the CLV1 ortholog SUNN acts as a central integration point. It responds to rhizobia-induced CLE peptides and to nitrogen-dependent systemic signals, including nitrate-induced CLE peptides, that influence lateral root growth in the absence of symbiosis. By contrasting these modules in Arabidopsis and Medicago, we show how legumes have layered symbiotic regulation onto ancestral nitrogen-signalling circuits that were first characterised in non-legume nitrate responses. This evolutionary perspective provides a mechanistic basis for future efforts to improve nitrogen use efficiency in crops by adjusting how CLE signalling, NIN/NLP activity and miR2111–TML-like modules link nitrogen status to root and nodule development.

In C3 plants, plastid carbonic anhydrases are essential for growth on ambient air but are not required for efficient CO2 assimilation.

(a) MIRO1 transcript levels were measured by RT-qPCR using two primer pairs targeting the upstream and downstream regions of the gene. Two-week-old seedlings were treated with mock or 10 µM flg22 for 2 h prior to RNA extraction. (b) sMIRO1 expression was assessed in transgenic plants expressing a GUS reporter driven by the MIRO1 promoter. Two-week-old seedlings were treated with mock or 10 μM flg22 for 2 h and followed by GUS staining. Dashed boxes indicate regions enlarged to the right. Scale bar, 50 μm. Scale bar in the enlarged views is 10 μm. (c) RT-qPCR (left) showing MIRO1 expression in 2-week-old WT, miro1-2 mutants, and miro1-2 complementation lines expressing GFP-MIRO1 under its native promoter. Immunoblot (right) showing GFP-MIRO1 protein levels in the GFP-MIRO1/miro1-2 complementation lines. GFP-MIRO1 was detected with anti-GFP. Equal loading was confirmed by Ponceau staining. Immunoblotting was repeated three times with similar results. (d) Stomatal apertures measured in WT and miro1-2 mutant cotyledons after treatment with mock, 1 µM or 10 µM flg22 for 2 h. (e) Stomatal apertures measured in 4-week-old WT and miro1-2 mutant rosette leaves after treatment with mock or 10 µM flg22 for 2 h. (f) Stomatal apertures measured in 2-week-old WT and...

Liu et al. show that O-acetylserine(thiol)lyase (OAS)-A1 regulates stomatal development by balancing cysteine and hydrogen peroxide. Hydrogen sulfide enhances OAS-A1 activity via persulfidation on Cys28 and Cys42, which affects stomatal density.

Photosystem II Subunit S (PsbS) is a critical regulator of non-photochemical quenching (NPQ), which is a protective mechanism triggered to dissipate excess l...

Melotto, M., Fochs, B., Jaramillo, Z. & Rodrigues, O. Fighting for survival at the stomatal gate. Annu. Rev. Plant Biol. 75, 551–577 (2024).

This protocol details the design principles and procedures for building programmable CRISPRi-based gene circuits, and for testing individual components and the assembled circuits in various plant spec...

The transcription factor NTT/WIP2 regulates cytokinin biosynthesis, signaling, and degradation genes (IPT5, AHP6, and CKX7, among others), modulating tissue-specific cytokinin homeostasis.