Wenjing Zheng

Lodging is a major constraint limiting grain yield in dry direct seeding rice (DDSR), yet the key traits and phenotypic relationships governing lodging resistance in japonica varieties adapted to this system remain poorly understood. This study evaluated 79 japonica accessions over two years in Shenyang, Northeast China, to dissect phenotypic variation in lodging index and identify ideotypes for breeding. Based on hierarchical clustering, varieties were classified into strong lodging resistance (SLR), medium lodging resistance (MLR), and weak lodging resistance (WLR) types, with SLR varieties achieving lodging indices 27.4–31.8% lower than those of MLR and 63.2–83.8% lower than those of WLR varieties. SLR varieties reduced lodging risk by coordinately balancing whole-plant bending moment and stem breaking resistance: plant height and center-of-gravity height were 5.2–10.7% lower, while basal internode bending stress was 27.9–81.9% higher than in other types. Structural equation modeling identified culm dry weight, inner diameter, and culm phenotype index as primary determinants of lodging variation. Notably, despite 11.0–13.7% fewer spikelets per panicle, SLR varieties maintained grain yields comparable to those of WLR varieties through compensatory increases in grain-filling rate (6.7–7.3%) and 1000-grain weight (8.1–8.7%). These findings demonstrate that optimizing basal internode structure and enhancing culm tissue density can simultaneously improve lodging resistance and preserve yield potential, providing a practical framework for breeding lodging-resistant, high-yielding japonica varieties for DDSR systems in Northeast China.

Rice blast is a major fungal disease that threatens global rice production and is caused by the fungus Magnaporthe oryzae . Therefore, cloning rice blast resistance-related genes, conducting indepth analyses of the interaction mechanisms between M. oryzae and rice, elucidating rice disease resistance pathways, and developing new resistant germplasms are crucial for ensuring food security. This study took the rice blast resistance-related protein kinase Pi65 as the research object and explored its regulatory role in the immune response of rice through protein phosphorylation omics and protein interaction verification. The experimental results demonstrated that Pi65 exhibited autophosphorylation kinase activity. Based on phosphoproteomic analysis, 572 and 107 differentially regulated phosphoproteins (DPPs) were identified in Pi65-knockout (KO) and Pi65-overexpression (OE) lines, respectively, compared with the wild type (WT). These DPPs showed significant changes in signal transduction, metabolic processes, and subcellular localization, indicating that altered Pi65 expression affects phosphorylation homeostasis in rice leaves. KEGG and GO enrichment analyses revealed that the DPPs in KO lines were mainly associated with biological processes such as nitrogen cycling and non-homologous end joining, whereas DPPs in OE lines were significantly enriched in pathways related to the calvin cycle, glycolysis, and RNA binding. Thus, Pi65 may participate in the regulation of cellular metabolism by modulating nuclear phosphorylation networks and post-transcriptional modification processes. Protein interaction validation experiments further confirmed that Pi65 directly interacted with the redox regulatory protein OsAPX4 and the phosphate transporter OsPHF1, linking Pi65 function to redox homeostasis and phosphorus signaling. These findings suggest that Pi65 acts as a key regulatory hub that integrates biotic and abiotic stress signals to modulate rice blast resistance via phosphorylation-dependent signaling cascades. This study provides new insights into the roles of plant kinases in multi-stress responses and offers potential candidate targets for genetic improvement of crop stress resistance.

The Cupin superfamily, characterized by a conserved β-barrel structure, plays crucial roles in plant growth, development, and stress responses. However, comprehensive analyses of this gene family in rice remains limited. Here, we performed a genome-wide identification, molecular evolution, and expression analysis of Cupin genes in rice under abiotic stress. Utilizing the telomere-to-telomere (T2T) genome of rice, 54 Cupin genes (OsCupins) were identified and classified into four subfamilies (GLP, PIRIN, TRR14, and ARD) based on phylogenetic relationships with Arabidopsis homologs. These genes were unevenly distributed across ten chromosomes, with tandem and segmental duplications driving their expansion. Structural and synteny analyses revealed conserved motifs and orthologous relationships with sorghum and Arabidopsis. The promoter regions of OsCupins were enriched in stress-responsive cis-elements, including ABRE, MYB, and MYC motifs. qRT-PCR data demonstrated the significant upregulation of multiple OsCupins (e.g., OsGLP15, OsGLP38, and OsGLP43) under NaCl and PEG 6000 treatments. Functional validation in yeast showed that the overexpression of OsGLP15, OsGLP38, or OsGLP43 enhanced salt and drought tolerance in yeast, with OsGLP43 exhibiting the strongest stress resilience. Our findings provide insights into the evolutionary dynamics and stress-responsive regulatory mechanisms of the Cupin superfamily in rice, offering potential targets for enhancing abiotic stress tolerance in this critical crop.

Rice bakanae disease (RBD), a major threat in rice-cropping nations, can reduce rice yield and quality. As it is a seed-borne disease, effective seed detection is crucial. Loop-mediated isothermal amplification (LAMP) can rapidly and specifically amplify DNA at a constant temperature with high sensitivity. This research uses LAMP to develop rapid RBD pathogen detection systems. Primers were designed targeting the NRPS31 gene of Fusarium fujikuroi and conserved TEF1α sequences of Fusarium asiaticum, Fusarium proliferatum, and Fusarium andiyazi. These reactions at 60 °C for 60 min had a detection limit of 100 pg·μL⁻¹, and LAMP proved applicable in field trials.

With the continuous improvement in living standards, consumers’ demand for rice quality has been increasingly growing. This study analyzed the quality characteristics of different rice varieties under various cultivation methods. This study examined the rice variety Liaoxing 21 (LX21), the upland rice variety Han 9710 (H9710), and the hybrid rice variety Liaoyou 7362 (LY7362) from Liaoning Province to evaluate the effects of transplanting (TP) and direct seeding (DS) on processing, appearance, nutritional, and tasting quality. The results indicated that the planting method (PM) had a relatively minor impact on processing quality. Compared to TP, DS significantly increased grain length (GL) by 1.19%, grain width (GW) by 2.69%, appearance (A) by 2.61%, stickiness (Ss) by 7.15%, degree of balance (DB) by 3.19%, apparent amylose content (AAC%) by 6.20%, fa by 0.66%, fa/fb₃ by 5.34%, and protein content (PC) by 19.93%. However, DS significantly reduced the grain length/width ratio (GL/W) by 1.03%, chalky grain rate (CGR) by 46.00%, chalkiness (CH) by 52.76%, and fb₃ by 4.23%. Compared to DS, TP resulted in a higher peak viscosity (PV), final viscosity (FV), and pasting temperature (PaT), whereas setback (SB) was lower. Among the tested varieties, LX21 exhibited superior milled rice rate (MRR), head rice rate (HRR), GL, GL/W, A, Ss, DB, taste value (T), and FV compared to H9710 and LY7362, while demonstrating significantly lower CGR, CH, hardness (H), fa, trough viscosity (TV), and peak time (PeT). Under the same planting conditions, the conventional rice variety LX21 demonstrated excellent processing, appearance, and taste quality, whereas H9710 exhibited favorable nutritional quality and Rapid Visco Analyzer (RVA) characteristics. Meanwhile, we also analyzed the correlation between temperature/light conditions and nutritional quality, as well as RVA profiles. The results showed that variations in temperature and light were closely associated with amylopectin accumulation and starch pasting properties. This study highlights the findings that selecting the appropriate PMs and japonica rice varieties can effectively enhance overall rice quality. In the medium maturing regions of Liaoning Province, adopting DS with medium–early maturing japonica rice varieties offers an optimal production strategy for achieving high quality, high yield, and efficient utilization of temperature and light resources.

The research on rice lodging resistance holds immeasurable value for achieving high yield, stable production, and superior quality of rice. To investigate the effects of mechanical properties and physicochemical characteristics of Japonica hybrid rice on its lodging resistance ability under natural field cultivation conditions, LY1052, LY9906, and GY1, which were mainly popularized in northern China, were selected as the experimental subjects, and NL313, Japonica hybrid rice prone to lodging, was taken as the control (NL313).The max bending force, breaking moment, bending section coefficient, single stem weight mass moment, bending strength, Young’s elastic modulus, inertia moment, and other mechanical indexes were measured by the bending test and tensile test, and the correlations between mechanical indexes, physicochemical indexes, and lodging index were studied. There was an extremely significant difference in the lodging index of experimental subjects and control (NL313) (p < 0.05). Therefore, it was concluded that the lower plant height and lighter panicle were not the stronger lodging resistance under appropriate cultivation conditions. Optimization of rice plant-type structure can achieve the unity of high culm and high yield. The lodging resistance of rice could be improved by shortening the internode length, increasing the tissue thickness and vascular bundle area, and increasing the content of cellulose and potassium in the stem. It was also found that the lodging resistance of rice plants was positively correlated with the maximum stem bending force, breaking moment, bending section coefficient, bending strength, and Young’s elastic modulus (p < 0.01) and negatively correlated with single stem weight mass moment and inertia moment (p < 0.01). It is feasible to select them as reference indexes of the lodging resistance of rice. The experimental results not only help to enrich the theoretical system of rice lodging resistance research but also provide an essential reference and basis for formulating scientific cultivation and management measures and breeding lodging-resistant rice varieties in practical production, which is of great significance for ensuring global food security and promoting sustainable agricultural development.

The PLATZ gene family, known for its pivotal roles in regulating plant growth, development, and stress responses, is of great significance in rice biology and crop improvement efforts. In this study, we undertook a comprehensive identification and analysis of the PLATZ gene family across 10 Oryza genus species, including both cultivated and wild rice varieties. A total of 144 PLATZ genes were identified, demonstrating their widespread distribution. Phylogenetic analysis revealed six distinct groups among these genes, with high sequence similarity among members indicating a common evolutionary origin and potential functional conservation. Further analysis of conserved motifs, domains, and promoter regions provided insights into the transcriptional regulation and potential functions of PLATZ genes. Notably, expression profiling showed differential expression patterns of specific PLATZ genes, such as OsPLATZ7, OsPLATZ9, and OsPLATZ11, under various abiotic stress conditions and hormone treatments, highlighting their important roles in stress adaptation and hormone signaling. Additionally, the consistently high expression of OsPLATZ9 across multiple tissues suggests its involvement in multiple developmental processes. Overall, this study provides a detailed characterization of the PLATZ gene family in rice, laying the foundation for future functional studies and potential applications in agricultural biotechnology.

Background: Rice, a staple food for over half of the global population, exhibits significant diversity in grain shape characteristics, which impact not only appearance and milling quality but also grain weight and yield. Identifying genes and loci underlying these traits is crucial for improving rice breeding programs. Previous studies have identified multiple quantitative trait loci (QTLs) and genes regulating grain length, width, and length-width ratio; however, further investigation is necessary to elucidate their regulatory pathways and their practical application in crop improvement. Methods: This study employed a genome-wide association study (GWAS) on 280 japonica rice varieties from northern China to decipher the genetic basis of grain shape traits. Phenotyping included measurements of 11 grain-related traits, such as grain length, width, and area, along with their brown and white rice counterparts. High-density single nucleotide polymorphism (SNP) markers (33,579) were utilized for genotyping, and GWAS was performed using a mixed linear model (MLM) incorporating principal component analysis (PCA) and kinship (K) matrix to account for population structure and relatedness. Results: Our analysis detected 15 QTLs associated with the 11 grain shape traits, of which five major QTL clusters emerged as crucial. Candidate genes, including LOC_Os01g50720 (qGL1), OsMKK4 (LOC_Os02g54600, influencing qBA2, qWL2, and qWA2), GW5 (LOC_Os05g09520, controlling qGW5, qBW5, qBR5, qWW5, and qWR5), GW6a (LOC_Os06g44100, associated with qGW6, qBW6, qBR6, qWW6, and qWR6), and FZP (LOC_Os07g47330, linked to qWL7), were identified based on functional annotations and haplotype analysis. These findings offer valuable insights into the genetic mechanisms underlying rice grain shape and suggest promising targets for marker-assisted selection to enhance rice quality and yield.