Journal of Integrative Plant Biology最新文献

Mitogen-activated protein kinase (MAPK) cascades play a fundamental role in plant immunity by transducing external signals inside plant cells. Here, we defined a wheat MAPK cascade, composed of the mitogen-activated protein kinase kinase (MAPKK) TaMKK2 and its downstream MAPK TaMAPK6, which phosphorylates the core immune regulator TaSGT1 (suppressor of G2 allele of Skp1), resulting in enhanced nuclear entry of TaSGT1, thereby conferring resistance against the devastating wheat pathogen Puccinia striiformis f. sp. tritici (Pst). Hence, we identified a TaMKK2-TaMAPK6-TaSGT1 signaling cascade that contributes to wheat stripe rust resistance. During infection, Pst secrets a haustorium-associated secreted protein 215 (HASP215), that targets TaMKK2 and interferes with the interaction of TaMKK2 with TaMAPK6 to suppress TaMAPK6 phosphorylation and activation, thereby leading to reduced capacity of TaMAPK6 to phosphorylate TaSGT1. Consequently, inhibition of TaMAPK6-mediated TaSGT1 phosphorylation resulted in decreased nuclear translocation of TaSGT1 and suppressed plant immunity. Our work elucidates the positive function of TaMKK2-TaMAPK6 cascade in wheat immunity by regulating the immune component TaSGT1, and its regulation by the rust effector HASP215, providing new insights into the MAPK cascade on crop immunity and the pathogenicity mechanism of obligate biotrophic fungus.

This commentary on Liu et al. (2025 JIPB) discusses the groundbreaking discovery that hydrogen sulfide (H₂S) modulates guard cell function by inhibiting inward-rectifying potassium channels through protein persulfidation, providing novel insights into the molecular mechanisms governing stomatal regulation and opening new avenues for enhancing plant stress resilience.

Synthetic microbial communities (SynComs) are a promising tool for making full use of the beneficial functions imparted by whole bacterial consortia. However, the complexity of reconstructed SynComs often limits their application in sustainable agriculture. Furthermore, inter-strain interactions are often neglected during SynCom construction. Here, we propose a strategy for constructing a simplified and functional SynCom (sfSynCom) by using elite helper strains that significantly improve the beneficial functions of the core symbiotic strain, here Bradyrhizobium elkanii BXYD3, to sustain the growth of soybean (Glycine max). We first identified helper strains that significantly promote nodulation and nitrogen fixation in soybean mediated by BXYD3. Two of these helper strains assigned to the Pantoea taxon produce acyl homoserine lactones, which significantly enhanced the colonization and infection of soybean by BXYD3. Finally, we constructed a sfSynCom from these core and helper strains. This sfSynCom based on the core-helper strategy was more effective at promoting nodulation than inoculation with BXYD3 alone and achieved effects comparable to those of a complex elite SynCom previously constructed on the basis of potential beneficial functions between microbes and plants alone. Our results suggest that considering interactions between strains as well as those between strains and the host plant might allow construction of sfSynComs.

The transcription factor bHLH25 acts as a H₂O₂ sensor in rice. Oxidized bHLH25 boosts lignin production to strengthen cell walls against pathogens, while non-oxidized bHLH25 activates phytoalexins to inhibit pathogen growth. This dual role balances defense and growth, offering a potential strategy for engineering disease-resistant crops without yield loss.

Hypoxia (low-oxygen tension) caused by complete submergence or waterlogging is an abiotic stress factor that severely affects the yield and distribution of plants. To adapt to and survive under hypoxic conditions, plants employ several physiological and molecular strategies that integrate morphological acclimation, metabolic shifts, and signaling networks. Group VII ETHYLENE RESPONSE FACTORS (ERF-VIIs), master transcription factors, have emerged as a molecular hub for regulating plant hypoxia sensing and signaling. Several mitogen-activated protein kinases and calcium-dependent protein kinases have recently been reported to be involved in potentiating hypoxia signaling via interaction with and phosphorylation of ERF-VIIs. Here, we provide an overview of the current knowledge on the regulatory network of ERF-VIIs and their post-translational regulation in determining plant responses to hypoxia and reoxygenation, with a primary focus on recent advancements in understanding how signaling molecules, including ethylene, long-chain acyl-CoA, phosphatidic acid, and nitric oxide, are involved in the regulation of ERV-VII activities. Furthermore, we propose future directions for investigating the intricate crosstalk between plant growth and hypoxic resilience, which is central to guiding breeding and agricultural management strategies for promoting flooding and submergence stress tolerance in plants.

Maintenance of endoplasmic reticulum (ER) homeostasis is central for plants to survive in changing cellular and environmental conditions. Although the role of ER in plant immunity is evident, how ER homeostasis is associated with activation of the immune response remains unclear. Here, we report that StDMP2, an ER-localized member of the DOMAIN OF UNKNOWN FUNCTION 679 membrane protein (DMP) family, positively regulates resistance to Phytophthora in potato (Solanum tuberosum). Heterologous expression of StDMP2 in tobacco (Nicotiana benthamiana) also enhances resistance to Phytophthora. Furthermore, StDMP2 is involved in both chemical- and pathogen-induced ER stress responses. Notably, StDMP2 plays a crucial role in several pathogen-associated molecular pattern-triggered immunity responses, and specifically contributes to the hypersensitive response triggered by the bacterial type-III secreted effector AvrRpt2, but not the Phytophthora infestans-secreted effector Avr3a. Further investigation revealed that StDMP2 affects the ER quality control-mediated accumulation of specific pattern recognition receptors and NON-RACE SPECIFIC DISEASE RESISTANCE 1. Collectively, these findings elucidate a mechanism by which StDMP2 promotes plant immunity through modulating ER homeostasis.

Tiller angle shapes plant architecture, and is one of the top traits in plant breeding. A compact plant type reduces shading between plants, especially at high planting density, but also creates a humid microenvironment often associated with a higher incidence of pathogen and pest attacks, especially under highly humid climates. However, how to precisely manipulate the tiller angle to achieve a desirable plant type has been under-approached. Here we report the creation of gradient tiller angles in indica rice by fine tuning the expression of TILLER ANGLE CONTROL1 (TAC1), a domesticated gene in cultivated rice. We edited the regions upstream and downstream of the TAC1 coding sequence using multiplex CRISPR-Cas9 technology and developed homozygous allelic lines carrying deletions/inversions of various sizes at different positions. Those lines displayed smooth gradient changes in tiller angle that aligned well with TAC1 expression levels. Additionally, changes in the TAC1 expression level had no impact on other agronomic traits examined. TAC1 is well conserved across species, including perennial fruit trees in which mutation of TAC1 orthologs leads to a broomy plant type. Thus, our results provide a guide to creating tiller angles for selection according to climate zones in rice breeding programs, this approach can be extended to diverse species for improving plant architecture.

The domains rearranged methyltransferases (DRMs) play a critical role in the RNA-directed DNA methylation (RdDM) pathway in plants. However, the effects of inactivating the RdDM pathway on gene expression, transposable element (TE) activity, and phenotype in soybean remain unexplored. Here, we employed clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 gene editing to generate a quintuple mutant line in soybean (Gmdrm2a^-/-2b^-/-2c^-/-3a^-/-3b^-/-, designated Gmdrm). Gmdrm exhibited severe developmental abnormalities, including dwarfism and delayed growth, albeit remaining viable and fertile; however, the fully homozygous mutant could be maintained for a limited number of generations (T0-T3). Whole genome bisulfite sequencing revealed a significant reduction in DNA methylation across all cytosine sequence contexts, with an average loss of 10%. The loss of ^mC was biased toward euchromatic regions, which is in contrast to the chromomethylase mutant. Transcriptome profiling identified 1,685 up-regulated genes, including photosynthesis-related genes, accompanied with altered chloroplast ultrastructure. Additionally, a cluster of resistance (R) genes on chromosome 16 was significantly up-regulated, coinciding with their reduced non-CG methylation. We also observed 3,164 differentially expressed TEs (DETs), of which, 2,655 were up-regulated and hypomethylated along their entire length. A substantial reduction in the abundance of 24-nt small interfering RNAs (siRNAs) in the Gmdrm mutant was detected by small RNA sequencing. Of note, the DRM-targeted TEs typically display higher levels of 24-nt siRNA abundance, shorter lengths, and are more AT-rich compared to chromomethylase-targeted TEs, highlighting 24-nt siRNAs as key determinants of DRM-dependent TE regulation. Together, this study documents a critical role of DRM-mediated DNA methylation in regulating gene expression, TE silencing, and normal development in soybean.

MYB transcription factors (TFs), one of the largest TF families in plants, are involved in various plant-specific processes as the central regulators, such as in phenylpropanoid metabolism, cell cycle, formation of root hair and trichome, phytohormones responses, reproductive growth and abiotic or biotic stress responses. Here we summarized multiple roles and explained the molecular mechanisms of MYB TFs in plant development and stress adaptation. The exploration of MYB TFs contributes to a better comprehension of molecular regulation in plant development and environmental adaptability.