The brassinosteroid (BR) receptor BRASSINOSTEROID-INSENSITIVE 1 (BRI1) plays a critical role in plant growth and development. Although much is known about how BR signaling regulates growth and development in many crop species, the role of StBRI1 in regulating potato (Solanum tuberosum) tuber development is not well understood. To address this question, a series of comprehensive genetic and biochemical methods were applied in this investigation. It was determined that StBRI1 and Solanum tuberosum PLASMA MEMBRANE (PM) PROTON ATPASE2 (PHA2), a PM-localized proton ATPase, play important roles in potato tuber development. The individual overexpression of StBRI1 and PHA2 led to a 22% and 25% increase in tuber yield per plant, respectively. Consistent with the genetic evidence, in vivo interaction analysis using double transgenic lines and PM H+-ATPase activity assays indicated that StBRI1 interacts with the C-terminus of PHA2, which restrains the intramolecular interaction of the PHA2 C-terminus with the PHA2 central loop to attenuate autoinhibition of PM H+-ATPase activity, resulting in increased PHA2 activity. Furthermore, the extent of PM H+-ATPase autoinhibition involving phosphorylation-dependent mechanisms corresponds to phosphorylation of the penultimate Thr residue (Thr-951) in PHA2. These results suggest that StBRI1 phosphorylates PHA2 and enhances its activity, which subsequently promotes tuber development. Altogether, our results uncover a BR–StBRI1–PHA2 module that regulates tuber development and suggest a prospective strategy for improving tuberous crop growth and increasing yield via the cell surface-based BR signaling pathway.
Brassinosteroids (BRs) are well known for their important role in the regulation of plant growth and development. Plants with deficiency in BR signaling show delayed plant development and exhibit late flowering phenotypes. However, the precise mechanisms involved in this process require investigation. In this study, we cloned homologs of BRASSINOSTEROID INSENSITIVE 2 (SlBIN2), the GSK3-like protein kinase in tomato (Solanum lycopersicum). We characterized growth-related processes and phenotypic changes in the transgenic lines and found that SlBIN2s transgenic lines have delayed development and slow growing phenotypes. SlBIN2s work redundantly to negatively regulate BR signaling in tomato. Furthermore, the transcription factor SlBIN2.1-INTERACTING MYB-LIKE 1 (SlBIML1) was identified as a downstream substrate of SlBIN2s that SlBIN2s interact with and phosphorylate to synergistically regulate tomato developmental processes. Specifically, SlBIN2s modulated protein stability of SlBIML1 by phosphorylating multiple amino acid residues, including the sites Thr266 and Thr280. This study reveals a branch of the BR signaling pathway that regulates the vegetative growth phase and delays floral transition in tomato without the feedback affecting BR signaling. This information enriches our understanding of the downstream transduction pathway of BR signaling and provides potential targets for adjusting tomato flowering time.
The obligate biotrophic fungus Puccinia striiformis f. sp. tritici (Pst) frequently overcomes host immunity through rapid evolution. The wheat landrace Paozimai exhibits high-temperature all-stage resistance (HTAS) to Pst, a type of resistance expressed at relatively high temperatures across all growth stages. In this study, we investigated host–pathogen interactions using integrated transcriptomic and data-independent acquisition proteomic analyses. Dual RNA-seq analysis at 192 and 216 h post-inoculation (hpi) revealed a shift in enriched Pst pathways during the late latent period, from endoplasmic reticulum protein processing and fatty acid metabolism at 192 hpi to carbohydrate and glutathione metabolism at 216 hpi. In the host, differentially expressed genes (DEGs) were enriched in defense-related signaling pathways at 192 hpi and in metabolic pathways at 216 hpi. Co-expression network analysis identified ribosomal and protein biosynthesis processes that may contribute to defense. Proteomic analysis showed greater overlap across time points, with oxidative phosphorylation enriched at 192 hpi and glycan biosynthesis at 216 hpi. Furthermore, integrated multi-omics and co-expression network analysis identified 16 candidate wheat genes, including genes encoding ribosomal proteins and stress-response proteins. These findings describe temperature-associated host and pathogen responses during HTAS and nominate candidates for functional validation.
Background: Nudix hydrolases (NHs), characterized by the conserved Nudix motif (GX5EX7REUXEEXGU), hydrolyze nucleoside diphosphate derivatives and play vital roles in plant stress responses and cellular homeostasis. However, the NH gene family has not been systematically characterized in maize (Zea mays L.). Methods: We performed a genome-wide analysis of ZmNH (Nudix hydrolase) genes using a maize pan-genome encompassing 26 high-quality genomes. Results: A total of 73 ZmNH members were identified, comprising 22 core genes (present in all 26 lines), 28 dispensable genes (present in 2–25 lines), and 23 private genes (present in only one line). Phylogenetic analysis clustered them into three subgroups (Type-I, -II, and -III), with Type-III being the largest (28 members). Gene structure and motif analyses revealed conserved exon–intron architectures and 10 conserved motifs. Nonsynonymous/synonymous substitution ratio (Ka/Ks) calculations across the 26 inbred lines indicated that most ZmNH genes were under purifying selection (Ka/Ks < 1), whereas ZmNH2 and ZmNH12 showed evidence of positive selection in some lines. Expression profiling under four stress conditions—Fusarium graminearum, Cercospora zeina, Exserohilum turcicum, and Ostrinia furnacalis—identified 20 differentially expressed ZmNH genes. Notably, ZmNH9 was consistently responsive across multiple pathogen treatments, suggesting a potential role in broad-spectrum disease resistance. Conclusions: These findings provide a foundation for future functional studies of the maize NH gene family.