Journal of Integrative Plant Biology最新文献

The UGT73 subfamily in Dioscorea nipponica exhibits remarkable catalytic diversity in glycosylation of steroidal saponins. Notably, DnU26 from the UGT73 subfamily and members of the phylogenetically distant UGT91 family independently evolved identical catalytic functions, revealing convergent evolution and the remarkable flexibility of plant glycosyltransferases in generating metabolic diversity.

This commentary highlights the role of DULL NITROGEN RESPONSE 1 (DNR1) in improving crops under changing climates. By understanding how DNR1 affects rice growth, the study paves the way for developing climate-resilient crop varieties (e.g., rice, wheat, and maize), potentially boosting yields and ensuring food security under elevated CO₂ levels.

Phytopathogens, such as the rice blast fungus Magnaporthe oryzae, suppress plant immunity for reproduction by secreting effectors into plant cells. The M. oryzae effector AvrPib is known to be recognized by Pib, an intracellular nucleotide-binding, leucine-rich repeat receptor (NLR), in rice. However, how AvrPib manipulates blast resistance and its potential targets in rice remains unclear. In this study, we showed that AvrPib interacts with the rice MAP KINASE KINASE KINASE 72 (OsMAPKKK72), a previously uncharacterized Raf-like MAPKKK. The osmapkkk72 mutant shows enhanced susceptibility to the M. oryzae strain Guy11 and reduced mitogen-activated protein kinase (MAPK) activation after treatment with chitin. Furthermore, OsMAPKKK72 interacts with MAP KINASE KINASE 9 (OsMKK9) and increases the interaction between OsMKK9 and OsMPK3/6. Accordingly, OsMKK9 positively regulates rice blast resistance and increases MAPK activation in an OsMAPKKK72-dependent manner following chitin treatment in rice, suggesting that OsMAPKKK72 may serve as a scaffold in the MAPK cascade. AvrPib inhibits the interaction between OsMAPKKK72 and OsMKK9, leading to reduced MAPK activation, which is mediated by OsMKK9. Taken together, our results reveal the critical roles of OsMAPKKK72 in blast resistance and uncover a mechanism wherein AvrPib suppresses rice blast resistance by interference with MAPK activation by targeting a key component in the MAPK cascade.

Steroidal glycoalkaloids (SGAs) are predominantly found in Solanaceous plants, including tomato (Solanum lycopersicum). In addition to their roles in resistance to herbivores, pathogens, and environmental stresses, SGAs exert antifungal, antibacterial, and anticancer effects. Over the past 15 years, the biosynthesis pathway of SGAs in tomato has been progressively investigated. A growing number of intermediate compounds and novel biosynthetic enzymes have been identified. In addition, various regulatory factors and their underlying regulatory mechanisms governing SGAs biosynthesis have been increasingly elucidated. Building upon these advances in understanding the SGAs biosynthetic pathway and its regulatory network, metabolic engineering of the SGAs pathway in tomato has been achieved using techniques such as gene editing. This mini review summarizes the current understanding of SGAs biosynthesis and regulatory mechanisms in tomato, and provides an overview of recent progress and future perspectives in metabolic engineering applications targeting this pathway.

This commentary explores recent advances that reveal how auxin transport and signaling precisely regulate its function in plant growth and development and offer new tools for precise plant engineering. These advances include a high-resolution structures of AUX1 and insights into TIR1-generated cyclic AMP signaling and the bi-layer ARF/cis-element code.

This review examines signaling peptides, which function in plant growth, development, and environmental adaptation, making them promising tools for crop improvement. Their gene-encoded nature and synthetic plasticity facilitate functional engineering. Engineered peptides offer superior binding affinity, functional specificity, and ligand stability, providing a multifaceted strategy to improve crop performance.

Mitogen-activated protein kinase (MAPK) cascades play vital roles in regulating plant growth, development, and stress responses. Nevertheless, the complete MAPK cascade that regulates the flowering time of Arabidopsis thaliana has not been established. A MAPK module comprising MAPKKK18, MAPKK3, and MAPK1/2/7/14 accelerates flowering in Arabidopsis. Through direct interaction, MAPK1/2/7/14 phosphorylates the S²⁴ residue of NF-YB2. Phosphorylated NF-YB2 enhances the stability of the heterotrimeric CO ~ NF-YB2 ~ NF-YC3/C9 complex and the expression of FT. Accumulation of NF-YB2 significantly promotes flowering, whereas the role of NF-YB2^S24A in this process is less pronounced. Compared with the transgenic plants overexpressing MAPKKK18 in the wild-type (WT) background, the nf-yb2 plants overexpressing MAPKKK18 bolt considerably later. Taken together, the MAPKKK18-mediated signaling cascade exerts tight control over the flowering time of Arabidopsis by modulating the phosphorylation status of NF-YB2, unveiling a flexible regulatory pathway to fine-tune plant development.

Gibberellins (GAs) and auxin play central regulatory roles in seed germination and root system development, respectively, so that the application of these phytohormones to crops would be worthwhile, with an increasing potential demand in agriculture. However, there are few effective chemicals that simultaneously enhance both GA and auxin signaling. Here, we report on an artificial thiourea derivative chemical, Y21, that serves as both a GA-signaling agonist and an auxin analog, promoting seed germination and root development, as well as low-phosphorus tolerance. Phenotypic, biochemical, and genetic evidence demonstrated that Y21 enhances the interaction between GA and its receptor GID1C via the Val239 amino acid residue and consequently promotes degradation of the DELLA proteins REPRESSOR OF ga1-3 (RGA) and RGA-LIKE 2. Furthermore, we found that Y21 interacts with the auxin receptor TIR1 via the Cys405 residue and thus promotes the turnover of the auxin-responsive Aux/IAA proteins. Consequently, Y21 significantly increases low-phosphorus tolerance of treated plants by positively regulating lateral root development. To our knowledge, Y21 is the first GA-signaling agonist to be identified, and our results also demonstrate that this potent synthetic chemical, identified by chemical genetic screening, is effective at modulating plant development and stress tolerance.

Transposable elements (TEs) are essential constituents of plant genomes, promoting environmental adaptation and modulating gene expression through novel insertions. Although their activities can also trigger deleterious mutations, host mechanisms have evolved to repress them. Similarly, TEs have developed strategies to counteract silencing for their propagation. Here, the LTR retrotransposon Copia2 was identified as an active TE in japonica rice, with variations in 5-base-pair repeats within its 5'-LTR influencing promoter activity. The expression of Copia2 could be activated by drought conditions, with CG-1 motifs on LTR acting as cis-acting elements recognized by calmodulin-binding transcription activators. Under drought stress, the interaction of drought-induced proteins SCT1 and SCT2 with calmodulin OsCML4 and OsCML31 further activates Copia2 expression, enhancing its sensitivity to Ca²⁺ signaling. Additionally, decreased DNA methylation of Copia2 under drought conditions, regulated by Ca²⁺ signaling, facilitates the binding of SCT1 and SCT2 to the LTR. In summary, the drought-induced activity of Copia2 is regulated by the synergy of SCT1/SCT2 and DNA methylation mediated through Ca²⁺ signaling, potentially contributing to its recent activity in rice.

This commentary on Du et al. (2025) demonstrates that transferring paired sensor-helper NLRs from Solanaceae to non-asterid species (rice, soybean, and Arabidopsis) overcomes restricted taxonomic functionality, enabling resistance to bacterial leaf streak without fitness costs, and unlocking cross-kingdom immune potential for crop protection.