Search Results (850)

Cooked-rice aroma strongly affects consumer choice, yet the chemical traits distinguishing glutinous rice from normal-amylose japonica rice remain underexplored because earlier studies targeted only a few dozen volatiles using one-dimensional gas chromatography–mass spectrometry (GC-MS). In this study, four glutinous and seven normal Japanese cultivars were cooked under identical conditions, their headspace volatiles trapped with MonoTrap and qualitatively profiled by comprehensive GC × GC-TOFMS. The two-dimensional platform resolved 1924 peaks—about ten-fold previous coverage—and, together with hierarchical clustering, PCA, heatmap visualization and volcano plots, cleanly separated the starch classes (78.3% cumulative PCA variance; Euclidean distance >140). Volcano plots highlighted 277 compounds enriched in the glutinous cultivars and 295 in Koshihikari, including 270 compounds that were not previously documented in rice. Normal cultivars were dominated by ethers, aldehydes, amines and other nitrogenous volatiles associated with grainy, grassy and toasty notes. Glutinous cultivars showed abundant ketones, furans, carboxylic acids, thiols, steroids, nitro compounds, pyrroles and diverse hydrocarbons and aromatics, yielding sweeter, fruitier and floral accents. These results expand the volatile library for japonica rice, provide molecular markers for flavor-oriented breeding and demonstrate the power of GC × GC-TOFMS coupled with chemometrics for grain aroma research. Full article

The brown planthopper, Nilaparvata lugens (Stål, 1854), is the most devastating pest of rice (Oryza sativa L.). Although insecticides are used to control this pest, host plant resistance is a more effective and economic solution. Therefore, identification of N. lugens-resistant genes and elucidation of their underlying resistance mechanisms are critical for developing elite rice cultivars with enhanced and durable resistance. Research has shown that in the long-term evolutionary arms race, rice has developed complex defense systems against N. lugens, while N. lugens has developed diverse and sophisticated strategies to overcome the plant’s defenses. This review emphasizes recent advances in the molecular interactions between rice and the N. lugens, particularly focusing on the resistance mechanisms of 17 cloned major N. lugens resistance genes, which have significantly improved our understanding of the molecular basis of rice–N. lugens interactions. We also highlight the roles of several N. lugens salivary components in activating or suppressing rice defense responses. These insights provide a foundation for developing sustainable and effective strategies to manage this devastating pest of rice. Full article

Growing demand for plant-based nutraceuticals drives the need for innovative bioprocessing strategies. This study developed an integrated approach combining germination and Lactobacillus-mediated fermentation to produce a γ-aminobutyric acid (GABA)-enriched functional beverage from brown rice. Systematic screening identified an optimal rice cultivar for germination. Sequential enzymatic liquefaction and saccharification were optimized to generate a suitable hydrolysate. Screening of 13 probiotic strains revealed that a 10-strain Lactobacillus–Bifidobacterium consortium maximized GABA synthesis (12.2 mg/100 g). Fermentation parameters were optimized to 0.25% monosodium glutamate, 4% inoculum, 10 μmol/L pyridoxine hydrochloride, 37 °C, and 24 h. The resulting beverage achieved significantly elevated GABA concentrations while exhibiting low fat (0.2 g/100 g), reduced caloric content (233.6 kJ/100 g), and high viable probiotic counts (2 × 10⁸ CFU/g). This strategy demonstrates significant potential for the scalable production of multifunctional, plant-based nutraceuticals with targeted bioactive components. Full article

Anaerobic germination (AG) is a pivotal trait for successful direct-seeded rice cultivation, encompassing rainfed and irrigated conditions. Elite rice cultivars are often vulnerable to flooding during germination, resulting in poor crop establishment. This drawback has led to the exploration of AG-tolerant rice landraces, which offer valuable insights into the genetic underpinnings of AG tolerance. Over the years, substantial progress has been made in identifying significant quantitative trait loci (QTLs) associated with AG tolerance, forming the basis for targeted breeding efforts. However, the intricate gene regulatory network governing AG tolerance remains enigmatic. This comprehensive review presents recent advances in understanding the physiological and genetic mechanisms underlying AG tolerance. It focuses on their practical implications in breeding elite rice cultivars tailored for direct-seeding systems. Full article

The improvement in yield in cultivar mixtures has been well established. Despite increasing knowledge of the improvement involving within-species diversification and resource use efficiency, little is known about the benefits arising from relatedness-mediated intraspecific interactions in cultivar mixtures. This study used a relatedness gradient of rice cultivars to test whether neighbor relatedness contributes to improvements in grain yields in cultivar mixtures. We experimentally demonstrated the grain yield of rice cultivar mixtures with varying genetic relatedness under both field and controlled conditions. As a result, a closely related cultivar mixture had increased grain yield compared to monoculture and distantly related mixtures by optimizing the root-to-shoot ratio and accelerating flowering. The benefits over monoculture were most pronounced when compared to the significant yield reductions observed in distantly related mixtures. The relatedness-mediated improvement in yields depended on soil volume and nitrogen use level, with effects attenuating under larger soil volumes or nitrogen deficiency. Furthermore, neighbor relatedness enhanced the richness and diversity of both bacterial and fungal communities in the rhizosphere soil, leading to a significant restructuring of the microbial community composition. These findings suggest that neighbor relatedness may improve the grain yield of rice cultivar mixtures. Beneficial plant–plant interactions may be generated by manipulating cultivar kinship within a crop species. A thorough understanding of kinship strategies in cultivar mixtures offers promising prospects for increasing crop production. Full article

Drought is a key limitation for rice productivity. While oxidative stress markers like hydrogen peroxide (H₂O₂) are important for drought adaptation, the predictive value of combining root anatomical and physiological traits is underexplored. We assessed 20 rice cultivars under drought and control conditions using a random forest, a multi-layer perceptron, and a SHAP-optimized stacking ensemble. The stacking ensemble achieved the highest classification accuracy (81.8%) and identified hydrogen peroxide, relative water content, and endodermis inner circumference as key predictors. SHAP analysis revealed important interactions between root anatomical and physiological traits, providing new biological insights into drought tolerance. Our integrative approach, supported by robust cross-validation, improves predictive power and transparency for breeding drought-resilient rice cultivars. Full article

Heavy metal contamination in paddy fields poses serious risks to food safety and crop productivity. This study evaluated the potential of native soil fungi as bioinoculants to reduce metal uptake in rice cultivated under contaminated conditions. Eight fungal strains—four indigenous and four allochthonous—were selected based on their plant growth-promoting traits, including siderophore production and phosphate solubilization. Additional metabolic analysis confirmed the production of bioactive secondary metabolites. In a greenhouse experiment, three rice cultivars were grown under permanent flooding (PF) and alternate wetting and drying (AWD) in soil enriched with arsenic, cadmium, chromium, and copper. Inoculation with indigenous fungi under AWD significantly reduced the arsenic accumulation in rice shoots by up to 75%. While AWD increased cadmium uptake across all cultivars, fungal inoculation led to a moderate reduction in cadmium accumulation—ranging from 15% to 25%—in some varieties. These effects were not observed under PF conditions. The results demonstrate the potential of native fungi as a nature-based solution to mitigate heavy metal stress in rice cultivation, supporting both environmental remediation and sustainable agriculture. Full article

The plant cuticle, a protective barrier against external stresses, and abscisic acid (ABA), a key phytohormone, are crucial for plant growth and stress responses. Heterologous expression of AtNCED3 in plants has been widely studied. In this research, by comparing the japonica rice cultivar Zhonghua 10 and its AtNCED3 over-expressing lines during the vegetative growth stage through multiple methods, we found that AtNCED3 over-expression increased leaf ABA content, enhanced epidermal wax and cutin accumulation, modified wax crystal density, and thickened the cuticle. These changes reduced leaf epidermal permeability and the transpiration rate, thus enhancing drought tolerance. This study helps understand the role of endogenous ABA in rice cuticle synthesis and its mechanism in plant drought tolerance, offering potential for genetic improvement of drought resistance in crops. Full article

Globally, rice cultivation consumes large amounts of fresh water, and urgent improvements in water use efficiency (WUE) are needed to ensure sustainable production, given increasing water scarcity. While stomatal traits have been a primary focus for enhancing WUE, complex interactions between stomatal and non-stomatal leaf traits remain poorly understood. In this review, we present an analysis of stomatal and non-stomatal leaf traits influencing WUE in rice. The data suggests that optimising stomatal density and size will be insufficient to maximise WUE because non-stomatal traits such as mesophyll conductance, leaf anatomy, and biochemical composition significantly modulate the relationship between stomatal conductance and the photosynthetic rate. Integrating recent advances in high-throughput phenotyping, multi-omics technologies, and crop modelling, we suggest that combinations of seemingly contradictory traits can enhance WUE without compromising yield potential. We propose a multi-trait breeding framework that leverages both stomatal and non-stomatal adaptations to develop rice varieties with superior WUE and climate resilience. This integrated approach provides a roadmap for accelerating the development of water-efficient rice cultivars, with broad implications for improving WUE in other crops. Full article

This study investigated how nitrogen fertilizer management influences the yield and grain quality of two rice cultivars, Nanjing 9108 (a late-maturing medium japonica) and Ming 1 Youzhenzhan (a three-line indica hybrid). Three field experiments were conducted to assess different nitrogen application strategies, including total nitrogen reduction, panicle-stage nitrogen reduction, and substitution of chemical fertilizer with compound fertilizer. The experiments analyzed changes in rice nitrogen uptake and transport efficiency, yield and its components, and quality and its components under different nitrogen application treatments, and fitted a function based on the effect of total nitrogen fertilizer on quality. Taking into account four quality indicators and ensuring yield reduction is less than 30%, replacing 100% chemical fertilizer with compound fertilizer in Nanjing 9108 was the optimal strategy for significantly improving quality. Reducing panicle fertilizer by 50% or omitting it also significantly improved quality. Replacing chemical fertilizers with 50% compound fertilizer also maintained nutritional quality. Reducing total nitrogen fertilizer by 25% in Ming 1 Youzhenzhan was the optimal strategy for significantly enhancing quality. Replacing chemical fertilizer with 100% compound fertilizer significantly improved quality. Reducing panicle fertilizer by 50% and substituting 50% of chemical fertilizer with compound fertilizer also significantly improved quality. Taking into account the synergistic effects of nitrogen application measures on rice yield and quality, the performance of the two rice varieties is not identical. The results showed that nitrogen fertilizer management significantly affected both yield and quality, with responses varying between the two varieties. But the two varieties can ensure optimal quality under yield conditions by reducing panicle fertilizer application by 50% and replacing chemical fertilizers with compound fertilizers. Full article

Assessing available phosphorus (P) in paddy fields is challenging due to waterlogging-induced reducing conditions. This study tested the applicability of the Truog, Bray 2, and Mehlich 3 extraction methods in both air-dried and incubated soils, as well as the ascorbic-acid-reduced Bray 2 (AR Bray 2), which simulates reducing conditions, for evaluating rice growth under P fertilization. In addition, to investigate the chemical characteristics of the extraction methods, active Al and Fe and P sequential extractions were measured. Soil samples from four representative regions in Yamagata Prefecture were used. Pot cultivation tests using ‘Haenuki’ and ‘Tsuyahime’ cultivars were conducted with varying P fertilizer levels. Variations in P availability across soil types were influenced by levels of active Al and Fe. Sequential extractions identified NaHCO₃-P and NaOH-P fractions as important for P availability. Bray 2 in both soils and AR Bray 2 were the most effective methods, showing a strong saturating exponential correlation with rice growth and P uptake, whereas Mehlich 3 and Truog showed weaker correlations. Bray 2 and AR Bray 2 show potential but require further evaluation for practical application due to the small number of soils. Future efforts should prioritize developing methods that account for P dynamics under reducing conditions, thereby improving P management strategies and supporting sustainable rice production. Full article

Rice (Oryza sativa L.), a staple food for over half of the global population, plays a pivotal role in food security. Among its two primary groups, japonica and indica, temperate japonica varieties are particularly valued for their high-quality grain and culinary uses. Although some of these varieties are adapted to cooler climates, they often suffer from reduced productivity or increased disease susceptibility when cultivated in warmer productive environments. These limitations underscore the need for breeding programs to incorporate biotechnological tools that can enhance the adaptability and resilience of the plants. However, New Genomic Techniques (NGTs), including CRISPR-Cas9, require robust in vitro systems, which are still underdeveloped for temperate japonica genotypes. In this study, we developed a reproducible and adaptable protocol for protoplast isolation and regeneration from the temperate japonica cultivars ‘Ónix’ and ‘Platino’ using somatic embryos as the starting tissue. Protoplasts were isolated via enzymatic digestion (1.5% Cellulase Onozuka R-10 and 0.75% Macerozyme R-10) in 0.6 M AA medium over 18–20 h at 28 °C. Regeneration was achieved through encapsulation in alginate beads and coculture with feeder extracts in 2N6 medium, leading to embryogenic callus formation within 35 days. Seedlings were regenerated in N6R and N6F media and acclimatized under greenhouse conditions within three months. The isolated protoplast quality displayed viability rates of 70–99% within 48 h and supported transient PEG-mediated transfection with GFP. Additionally, the transient expression of a gene editing CRISPR-Cas9 construct targeting the DROUGHT AND SALT TOLERANCE (OsDST) gene confirmed genome editing capability. This protocol offers a scalable and genotype-adaptable system for protoplast-based regeneration and gene editing in temperate japonica rice, supporting the application of NGTs in the breeding of cold-adapted cultivars. Full article

Climate change poses significant challenges to temperate rice production, particularly affecting grain quality and market acceptance. This review synthesizes current knowledge of climate-induced quality changes, with a focus on the Australian rice industry as a case study with comparisons to other temperate regions. Environmental stressors such as extreme temperatures, variable rainfall, elevated CO₂, and salinity disrupt biochemical pathways during grain development, altering physicochemical, textural, and aromatic traits. Different rice classes exhibit distinct vulnerabilities: medium-grain japonica varieties show reduced amylose under heat stress, aromatic varieties experience disrupted aroma synthesis under drought, and long-grain types suffer kernel damage under combined stresses. Temperature is a key driver, with quality deterioration occurring above 35 °C and below 15 °C. Systems biology analyses reveal complex signalling networks underpinning these stress responses, although experimental validation remains limited. The Australian industry has responded by developing cold-tolerant cultivars, precision agriculture, and water-saving practices, yet projected climate variability demands more integrated strategies. Priorities include breeding for stress-resilient quality traits, refining water management, and deploying advanced phenotyping tools. Emerging technologies like hyperspectral imaging and machine learning offer promise for rapid quality assessment and adaptive management. Sustaining high-quality rice in temperate zones requires innovation linking physiology with practical adaptation. Full article

C2H2 zinc finger proteins (C2H2-ZFPs) constitute one of the largest transcription factor families in plants, playing crucial roles in growth, development, and stress responses. Here, we performed a comprehensive genome-wide analysis of C2H2-ZFPs in foxtail millet (Setaria italica v2.0), identifying 67 members that were unevenly distributed across all nine chromosomes. Most SiC2H2 proteins were predicted to be alkaline, stable, and nuclear-localized, with the exception of SiC2H2-11 and SiC2H2-66, which were chloroplast-targeted. Phylogenetic analysis with Arabidopsis thaliana and Oryza sativa (rice) homologs classified these genes into seven distinct subfamilies, each containing the characteristic motif1 domain. Evolutionary studies revealed 14 segmental duplication events and strong syntenic conservation with Triticum aestivum (wheat, 163 orthologous pairs), suggesting conserved functions during evolution. Promoter analysis identified multiple cis-acting elements associated with light responsiveness, hormone signaling, and stress adaptation. Transcriptome profiling and qPCR validation in the YuGu 56 cultivar identified several stress-responsive candidates, including SiC2H2-35 and SiC2H2-58 (salt tolerance), as well as SiC2H2-23 (5.19-fold induction under salt stress) and SiC2H2-32 (5.47-fold induction under drought). This study provides some valuable insights into the C2H2-ZFP family in foxtail millet and highlights potential genetic markers for improving stress resilience through molecular breeding approaches. Full article

Rice is a staple food for over half of the world’s population, and it is grown in over 100 countries. Rice blast disease can cause 10% to 30% crop loss, enough to feed 60 million people. Breeding for resistance can help farmers avoid costly fungicides. This study assessed the relationship between rice blast disease and zinc or anthocyanin content in biofortified rice. Susceptibility to foliar and panicle blast was assessed in a rice panel which differed on grain zinc content and pigmentation. A rice panel (n = 23) was challenged with inoculum of two isolates of Magnaporthe oryzae in a screenhouse-based assay. The zinc content with foliar blast severity was analyzed in the leaves and grain of a subset of non-inoculated rice plants. The effect of foliar zinc supplementation on seedlings was assessed by varying levels of zinc fertilizer solution on four blast susceptible cultivars at 14 days after planting (DAP), followed by inoculation with the blast pathogen at 21 DAP. Foliar blast severity was scored on a 0–9 scale at 7 days after inoculation. The rice panel was scored for anthocyanin content, and the data were correlated with foliar blast severity. The panel was grown in the field, and panicle blast, grain yield and yield-related agronomic traits were measured. Significant differences were observed in foliar blast severity among the rice genotypes, with IRBLK-KA and IR96248-16-2-3-3-B having mean scores greater than 4, as well as BASMATI 370 (a popular aromatic variety), while the rest of the genotypes were resistant. Supplementation with foliar zinc led to a significant decrease in susceptibility. A positive correlation was observed between foliar and panicle blast. The Zn in the leaves was negatively correlated with foliar blast severity, and had a marginally positive correlation with panicle blast. There was no relationship between foliar blast severity and anthocyanin content. Grain yield had a negative correlation with panicle blast, but no correlation was observed between Zn in the grain and grain yield. This study shows that Zn biofortification in the grain may not enhance resistance to foliar and panicle blast. Furthermore, the zinc-biofortified genotypes were not agronomically superior to the contemporary rice varieties. There is a need to apply genomic selection to combine promising alleles into adapted rice genetic backgrounds. Full article