SDJ, a pollen-expressed type III J-protein in Prunus, directly binds S-RNase and promotes recruitment of SLFL6 to an S-RNase-associated complex

PbrFEN-1 positively regulates pear pollen tube growth and is involved in the self-incompatibility response

An extended N-terminus restrains the plant cell death-inducing ability of the catalytically competent ribonuclease domain in a pea powdery mildew RALPH effector

A previously unrecognized mechanism regulating RNase activity in a dicot PM RALPH effector is revealed and new insights are provided into the functional diversification of RALPHs and their adaptation to obligate biotrophy.

BAM3 Is a CLE19 Receptor that Mediates a Distinct Signaling Branch Controlling Tapetum Degeneration and Pollen Wall Formation.

This work demonstrates how combinatorial peptide-receptor usage expands the signaling capacity of a single developmental peptide to coordinate robust male reproductive development.

A conserved COBL3-like protein promotes PDLP5-dependent callose accumulation to confer broad-spectrum plasmodesmata-mediated antiviral defense.

Plasmodesmata (PD) play vital roles in plant growth and defense through controlling symplastic transport of important molecules. Here we report that a conserved COBRA-like protein, COBL3, is required for PD-mediated antiviral defense (PMAD) against divergent plant RNA viruses in wheat (Triticum aestivum) and tobacco (Nicotiana benthamiana) via positively regulating callose accumulation. The wheat COBL3 protein, TaCOBL3, interacts with the 17K movement protein (MP) of barley yellow dwarf virus-GAV (BYDV-GAV). TaCOBL3 is associated with the plasma membrane and co-locates with 17K MP at PD. Genetic analysis with overexpression and knockout lines reveals that TaCOBL3 positively regulates wheat defense against BYDV-GAV through modulating callose accumulation at PD. Interestingly, TaCOBL3 interacts with the wheat homolog of PDLP5, a conserved key PD permeability regulator in higher plants. Silencing TaPDLP5 diminishes the elevated BYDV-GAV defense conferred by TaCOBL3 overexpression in wheat. Furthermore, transient expression of TaCOBL3 promotes callose accumulation and lowers PD permeability in tobacco cells, which is, however, largely compromised when tobacco PDLP5 is silenced. Notably, BYDV 17K MP weakens the interaction between TaCOBL3 and TaPDLP5 and inhibits their callose binding activities. Finally, silencing tobacco NbCOBL3 gene decreases callose content and attenuated host defense against two tobraviruses, one potexvirus, and one hordeivirus. Overall, our study reveals a previously unknown role of COBRA-like proteins in PMAD and provides insight into how a plant viral MP sabotages PMAD through perturbing COBL3-PDLP5 interaction to facilitate virus spread through PD. The conserved COBL3 gene may represent a valuable target for engineering broad-spectrum antiviral resistance in crop plants.

Genome-wide characterization of the wheat cryptochrome/photolyase family identifies TaCRY1b as a lamina-joint-associated protein interacting with TaLG2 and TaLG2L

Background Cryptochromes (CRYs) are blue light and ultraviolet A (UV-A) photoreceptors that play pivotal roles in regulating plant development and stress responses through mediating light signaling pathways. However, the evolutionary and functional characteristics of the cryptochrome/photolyase (CRY/PHL) family in wheat (Triticum aestivum L.) remain poorly understood. Results 57 CRY/PHL genes were identified across eight species, including 14 members in hexaploid wheat. Phylogenetic analysis classified CRY/PHLs into four subfamilies. All TaCRY/PHL proteins contain the conserved photolyase homology region (PHR), whereas the cryptochrome C-terminal (CCT) domain is exclusively present in the CRY1 subfamilies. Collinearity analysis revealed extensive synteny among wheat, rice, and maize CRY/PHLs, but not with Arabidopsis, indicating lineage-specific evolution within grasses. Promoters of TaCRY/PHL genes contain multiple predicted light-, hormone-, and stress-responsive cis-elements. Tissue-specific expression profiling demonstrated that subfamily A and C members are predominantly expressed in vegetative tissues, while subfamily B and D members are mainly expressed in reproductive organs. Notably, TaCRY1b expression progressively increased during leaf lamina joint (LJ) development. Subcellular localization demonstrated that TaCRY1b localizes to both the nucleus and cytoplasm, while bimolecular fluorescence complementation assays uncovered direct physical interactions between TaCRY1b and TaLiguless2 (TaLG2s), key regulators of LJ formation. AlphaFold3 prediction showed a putative interaction interface between TaLG2/TaLG2L and TaCRY1b, where multiple complementary residue pairs form polar contacts predominantly within the PHR domain of TaCRY1b. Conclusions This study provides a comprehensive framework for the evolution and functional diversification of the wheat CRY/PHL family and identifies TaCRY1b as a promising candidate regulator of lamina joint development, laying a solid foundation for further investigations into its moltcular function in leaf angle modulation.

The divergent V2 protein encoded by parsley yellow leaf curl virus is a suppressor of transcriptional and post-transcriptional gene silencing and a potential symptom determinant

The Geminiviridae family encompasses over 500 species of economically important plant viruses. A new geminivirus species named parsley yellow leaf curl virus (PYLCV) was first identified in 2020 in Southeastern Iran. The PYLCV genome, comprising 2,779 nucleotides, exhibits a pairwise sequence identity of less than 66% with other geminiviruses and encodes a divergent V2 protein that lacks sequence similarity to known proteins in GenBank. This study explores the functions of this V2 through various analyses. An assessment of the V2 amino acid composition indicates a higher prevalence of acidic residues. By expressing N-terminal and C-terminal GFP fusions (GFP-V2 and V2-GFP) in Nicotiana benthamiana, we demonstrate that V2 localizes to the cytoplasm, nucleus, endoplasmic reticulum, and the Cajal body. Notably, PYLCV V2 suppressed local PTGS and delayed systemic PTGS in GFP-based silencing assays and restored GFP transcript accumulation in a systemic 16c-TGS assay, indicating suppression of transcriptional silencing. Co-immunoprecipitation assays further showed that PYLCV V2 interacts with NbAGO4-1 and with itself, but not detectably with NbSGS3 or NbHDA6, supporting a potential role for PYLCV V2 in targeting the AGO4-mediated transcriptional silencing pathway. Ectopic expression of V2 via a PVX vector induced necrotic lesions with HR-like features, together with systemic mosaic patterns and severe leaf curling in upper leaves. Importantly, PYLCV V2 retains core V2-like biological activities despite extensive primary-sequence divergence, suggesting that functional conservation may rely on structural or biophysical determinants rather than linear sequence similarity. Our findings demonstrate that the divergent V2 protein from PYLCV has the capacity to function as a viral suppressor of RNA silencing (VSR) and as a potential symptom determinant, suggesting relevant roles in viral pathogenicity analogous to those of other geminiviral V2 proteins.