Forage-grain ratoon rice (FG-RR) is a sustainable system designed to enhance ratoon rice yield and quality while simultaneously producing high-quality whole-plant rice forage through early harvesting of the immature main crop (MC) for silage. This study examined the effects of planting density and mowing time on forage and grain productivity and quality, to optimize ecological and economic benefits. Field experiments were conducted using two cultivars, Liangyou 6326 and Taoyouxiangzhan, across five planting densities (17.26 & times; 104-34.52 & times; 104 hills ha-1) and four mowing stages (heading, milk-ripening, dry-ripening, and full maturity). Forage and ratoon crop (RC) yields, quality traits, resource utilization efficiency, and economic returns were assessed. Increasing planting density initially promoted but subsequently reduced both forage and RC yields. Delayed mowing increased forage yield but, after an initial rise, reduced RC yield. The optimal combination-mowing at the milk-ripening stage with a planting density of 28.82 & times; 104 hills ha-1 produced forage containing 53.72% neutral detergent fiber, 21.26% starch, and 9.93% crude protein, meeting standards for high-quality silage. In the RC season, the head rice rate reached up to 58.61% with a chalkiness level as low as 4.17%, meeting high-quality edible rice standards. TOPSIS analysis and economic evaluation indicated that this management strategy yielded the highest overall performance, generating 3086.08 USD & centerdot;ha-1. Integrating this optimal mowing time with optimal density produced 31.88 t & centerdot;ha-1 of high-quality forage and 7.13 t & centerdot;ha-1 of premium-grade rice. This integrated strategy enhances resource utilization efficiency, grain quality, and profitability, offering a practical approach for the sustainable development of FG-RR systems.

The forage-grain ratoon rice system enables the harvesting of main crop for silage, followed by the harvesting of the ratoon crop for grain. A two-year study was conducted in Xinyang City, Henan Province, China to assess the effects of nitrogen (N) application rates (135, 270, and 405 kg ha-1 ) and stubble heights (0, 15, 25, 35, and 45 cm) at the main crop harvest on forage quality and ratoon performance in the forage-grain ratoon rice system. Results showed that high stubble heights (35 and 45 cm) significantly improved forage quality via reduced neutral/acid detergent fiber and increased crude protein and starch contents compared with the stubble height of 0 cm. High stubble heights also shortened the ratoon growth period by 12-18 d and increased the daily mean temperature and solar radiation by up to 1.93 degrees C and 0.49 MJ m-2 d-1 , respectively. When combined with 270 or 405 kg N ha-1 , high stubble heights increased tiller density, leaf area index, and canopy light interception, thereby enhancing post-anthesis biomass accumulation, crop growth rate, and the use efficiencies of both thermal energy and solar radiation in the ratoon crop. Consequently, the ratoon grain yield was increased by 43%-60%, which was mainly due to more panicles from the upper two nodes. These findings suggest that optimizing the stubble heights and N management is key to maximizing agronomic performance in the forage-grain ratoon rice system.

Higher grain weight and stronger seed dormancy are key objectives for improving rice (Oryza sativa) yield and inhibiting pre-harvest sprouting. Therefore, identifying genes that coordinately regulate grain weight and seed dormancy is an urgent priority. Here, we report that knocking out miR1866 (KO1866) increased grain weight and reinforced dormancy. We identified the transcript of ubiquitin-specific processing protease 7 (OsUBP7), which encodes a protein with deubiquitination activity in vitro, as the primary target of miR1866. Consistent with miRNA-directed repression, OsUBP7 transcript abundance generally showed a spatiotemporal pattern opposite to miR1866 accumulation during rice development. Overexpression of native OsUBP7 (UBP7-OE) or a miR1866-resistant form (mUBP7-OE) phenocopied KO1866 by producing heavier grains with stronger dormancy. The miR1866-OsUBP7 module also altered the expression of genes associated with sucrose and starch metabolism, cell-cycle control, grain development, and abscisic acid (ABA) biosynthesis and signaling. Accordingly, KO1866, UBP7-OE, and mUBP7-OE plants contained more ABA and responded more sensitively to exogenous ABA than wild type. OsUBP7 interacted with OsDA1 (encoded by Os06g0182500) and UBIQUITIN-CONJUGATING ENZYME (OsUCE1; encoded by Os02g0833300), thereby affecting hull cell division and ABA signaling and ultimately regulating grain weight and seed dormancy, respectively. Our results indicate that the miR1866-OsUBP7 module regulates grain weight and seed dormancy in rice, highlighting its potential for engineering crops with improved yields and stronger seed dormancy.

Understanding the mechanisms underlying yield differences among rice planting regions is crucial for boosting the yield potential of low-producing regions and ensuring global food security. Although climate factors affecting rice yields in different sites have been widely studied, the microbial ecological processes and environmental mechanisms that promote super rice yields remain poorly understood. This study analyzed the composition, assembly mechanisms, and functions profiles of rhizosphere and soil microbial communities in five representative super rice production regions across China, including Handan (Hebei, temperate zone, drab soil), Xinyang (Henan, subtropical zone, clay loam soil), Xupu and Longhui (Hunan, subtropical zone, paddy soils), and Gejiu (Yunnan, tropical highland paddy soil). Our results revealed that the assembly mechanisms of rhizosphere microbial communities were primarily dominated by stochastic processes (accounting for 79.54 %), mainly including dispersal limitation and undominated processes. In contrast, bulk soil microbial communities were predominantly shaped by deterministic processes (contributing to 72.18 %), primarily homogeneous selection. Distance-decay relationships indicated that bulk soil microbial communities were more susceptible to latitude and environmental factors (R-2 = 0.13, p < 0.001), while rhizosphere microbial communities exhibited greater stability due to the buffered rhizosphere microenvironment. Partial Least Squares Path Modeling further demonstrated that rhizosphere microbes exerted stronger influences on rice growth compared with bulk soil microbes. Further predictions showed that the high-yielding Gejiu site selectively recruited rhizosphere microbes enriched in nutrient cycling and transport pathways, including glyoxylate and dicarboxylate metabolism, inositol phosphate metabolism, and nitrogen metabolism. These functions enhanced nutrient availability and supported higher biomass (70.96 g plant(-1)). Collectively, our findings suggest that the stochastic assembly of rhizosphere microbial communities confers functional stability, and their enrichment in nutrient cycling functions represents a key biological mechanism driving regional differences in super rice yields.

Nitrogen (N) is an essential macronutrient for food crops. Plants respond to low N (LN) stress through altering their root morphology. Strigolactones (SLs) are important modulators of root growth in plants. However, the functions of SLs and their downstream pathway in N-modulated formation of crown roots (CRs) remain unclear. In this study, we found that LN inhibits the occurrence of CRs in rice, with significant differences observed between japonica and indica varieties. A natural variant of D17, a gene involved in SL biosynthesis, was identified as participating in this process, revealing that SL is involved in LN-inhibited CR development in rice. Mutations in D17 and D53 (an SL signalling repressor) caused CR development under N deficiency. Under LN conditions, the perception of SLs by D14 triggered the ubiquitin-proteasome-mediated degradation of D53, thereby releasing SPL14 and SPL17 (SPL14/17) to inhibit CR formation and ultimately resulting in fewer CRs in rice. Additionally, SPL14/17 interacted with WOX11 and repressed its transcriptional activity by attenuating its DNA-binding ability. Moreover, loss of WOX11 function in the spl14 spl17 double mutant suppressed the enhanced CR formation observed under LN conditions, demonstrating that WOX11 acts downstream of SPL14/17 to induce rice CR formation in response to different levels of N supply. Taken together, our findings suggest a novel regulatory pathway in which D53-SPL14/17-WOX11 module modulates CR development adaptations to changes in N availability in rice.

Nitrogen (N) management is critical for ensuring food security and mitigating greenhouse gas (GHG) emissions. In rice paddies, the effectiveness of N management in maximizing yields and minimizing N losses is highly dependent on local environmental conditions and thus varies widely across regions. However, the influence of optimized, site-specific N management on methane (CH4) emissions remains poorly quantified and is not reflected in current IPCC Tier 1 methodologies. Here, we synthesize data from multiregional field experiments and conduct a meta-analysis to show that locally optimized N management practices-such as delayed fertilizer application, reduced N input, and deep placement-reduce CH4 emissions from rice paddies by 16%-21%. The experiments further show that these practices suppress CH4 emissions by lowering soil N availability and organic matter decomposition, thereby limiting substrates for methanogenesis. Combining survey data from 155 counties with machine learning models, we estimate that implementing optimized N strategies across China's rice-growing regions could reduce CH4 emissions by 16% while simultaneously increasing rice yields by 7%. These findings underscore the dual benefits of locally optimized N management for agricultural productivity and climate change mitigation, and provide a foundation for improving CH4 emission estimates under diverse management regimes.

Intercropping systems that increase crop yield and land use efficiency are becoming increasingly popular worldwide, especially in developing countries. Despite many advantages related to nutrient, light, temperature, water, and land use efficiencies, intercropping of rice subspecies such as Indica and Japonica has not yet been fully explored. Hence, a two-year field experiment was conducted to study the effects of Indica-Japonica (i.e., XLY900-YY9 and YLY900-YY9) intercropping on the rice yield depending on sowing dates, and the intercropping effects were evaluated by yield, land equivalent ratio (LER), interspecific relative competitiveness (A), and relative crowding index (K). The Indica-Japonica intercropping at I1J1 sowing dates had cumulative yields of 12 t ha-1 (20%-23%) higher than the yield of Indica or Japonica under mono-cropping. This increase was mainly due to the efficient use of light and a higher photosynthetic rate. The LER values (1.23-1.27) and those of the relative crowding index (K) (1.69-5.36) were both greater than 1, indicating that intercropping used land more efficiently than mono-cropping. The interspecific relative competitiveness (A) showed Indica to be more competitive (A > 0, ranging from 1.05 to 1.80), while Japonica was less competitive (A < 0, ranging from -1.05 to -1.80), but with reduced overall competition between the two for light and land resources. Hence, Indica-Japonica intercropping has high potential to maximize rice yield while utilizing the natural resources more efficiently, and could contribute to food security, particularly in regions where rice is a staple crop.

Long non-coding RNAs (lncRNAs), representing the non-coding RNA regions, constitute a significant portion of the genomes in complex organisms. Recent studies suggest that some lncRNAs have the capability to encode peptides. However, the presence of the lncRNA-derived sORFs-encoded polypeotides (LSEPs) in plants is not well understood. In this study, we developed a multi-omics approach that encompasses transcriptomics, translatomics (Ribo-seq), and proteomics to identify of LSEPs in rice. Among the 2764 identified lncRNAs, 42.69% were found to be bound by the ribosome, indicating a potential for encoding. Optimized small peptide extraction protocol was further developed, and the small peptides from rice leaves were extracted and subjected to LC-MS/MS analysis, leading to the identification of a total of 403 LSEPs across four constructed search databases. This work confirms the peptide-coding ability of lncRNAs in plants. Collectively, our study establishes an efficient multi-omics method for identifiying small peptides encoded by lncRNAs, which may be valuable for large-scare screening of LSEPs in plants. ### Competing Interest Statement The authors have declared no competing interest.

To enhance the quality of forage-grain ratoon rice (FGR) and promote the sustainable development of both rice and livestock industries in southern China, this study investigates the microbial fermentation dynamics of co-ensiling FGR with maize or sorghum-sudangrass hybrid. Results demonstrate that co-ensiling with maize significantly improved fermentation quality, reducing fiber content and enhancing lactic acid production, compared with sorghum-sudangrass hybrid. The optimal FGR-to-maize ratio of 75:25 yielded the lowest neutral detergent fiber and acid detergent fiber values and the highest lactic acid concentration (39.37 g/kg DM). Co-ensiling promoted the growth of beneficial lactic acid bacteria (LAB), particularly Lactobacillaceae and Sporolactobacillaceae, thus enhancing fermentation efficiency. Additionally, inoculation with Lactobacillus plantarum improved silage stability by promoting LAB growth and inhibiting the growth of undesirable Enterobacter species. This study offers a sustainable strategy to optimize rice straw utilization for livestock feed, reduce dependence on imported forages, and support agricultural sustainability in China.

Intercropping is widely practiced to improve crop yield and resources use efficiency. However, its effect on rice, especially the subspecies rice such as Indica and Japonica intercropping is elusive. A two-year field experiment (2021–2022) was conducted to assess the effects of Indica-Japonica intercropping on rice growth, yield, and quality. Results showed that intercropping increased the leaf area and efficient leaf area of Indica by 45

Arsenic (As) contamination severely limits plant growth and poses a significant threat to human health due to its accumulation in crops like rice. Phytochrome B (PhyB) regulates plant development and responses to abiotic stress, but its role in modulating As stress and regulating As accumulation in rice remains unclear. In this study, we examined the physiological and molecular responses of rice phytochrome B (OsPHYB) knockout (OsPHYB-KO) lines compared with wild-type (WT) plants under arsenite [As(III)] stress. Under As(III) exposure for 7 days, OsPHYB-KO seedlings exhibited significantly increased root length (40.42 %-58.08 %), shoot height (7.41 %-9.22 %), and dry biomass (18.88 %-37.41 %) compared with WT. Chlorophyll fluorescence analysis showed enhanced photosynthetic efficiency in OsPHYB-KO lines, with significant increases in maximum photochemical efficiency of PSII (Fv/Fm) and effective photochemical quantum yield of PSII (φPSII). Notably, As concentrations in both shoots and roots of OsPHYB-KO plants were reduced by 39.78 %-51.89 % and 28.26 %-33.79 %, respectively, compared with WT. OsPHYB-KO lines had 25.56 %-55.63 % higher antioxidant enzyme activities and 43.10 %-54.60 % lower malondialdehyde levels, indicating improved tolerance to oxidative stress. Transcriptomic profiling and qRT-PCR revealed upregulation of genes involved in melatonin (MT) biosynthesis and glutathione (GSH) metabolism, with MT content increased by 16.20 %-67.96 % and GSH content elevated by 38.51 %-117.12 % in both roots and shoots of OsPHYB-KO plants. These results demonstrate that OsPHYB plays a crucial role in As(III) detoxification and provide a foundation for developing low-As rice cultivars.

Super hybrid rice has significantly enhanced agricultural productivity in China, yet its environmental sustainability implications remain poorly understood. Using the food-carbon-nitrogen-energy-profit (FCNEP) framework, we evaluated five elite varieties (LYPJ, YLY1, YLY2, YLY900, XYL900) cultivated between 1999 and 2017. Field experiments were conducted from 2015 to 2017 across four provinces (Hubei, Hunan, Henan, and Jiangxi Province) in central China under four nitrogen treatments (0, 210, 300, 390 kg N/ha). Our findings reveal that while variety evolution boosted yields and reduced energy footprints (EFs), it also resulted in an increase in the nitrogen and carbon footprint (CF). Compared with LYPJ, newer varieties increased yields by 15.0–21.7% and net profits by 25.9–40.3%, while reducing energy footprints by 16.3–22.7%. However, nitrogen and carbon footprints rose by 8.0–34.5% and 31.0–76.6%, respectively. The composite sustainability score, derived from the FCNEP framework, indicated an initial improvement in sustainability during the early breeding stages of super hybrid rice. However, as breeding advanced, the sustainability score showed a subsequent decline. This study underscores the trade-off between enhancing productivity and maintaining environmental sustainability in superhybrid rice breeding. Future super hybrid rice breeding initiatives should prioritize balancing yield improvements with environmental considerations to promote sustainable agricultural development.

Salt stress severely limits rice growth and productivity. Auxin signaling has a well-documented role in development, but its role in rice salt stress responses is far from clear. In this study, we identified OsARF12, an auxin response factor, as a critical positive regulator of salt tolerance in rice. Transcript analysis revealed salt-induced upregulation of OsARF12. More importantly, OsARF12 overexpression (OsARF12-OX) induced significantly increased survival rates and reduced biomass loss under 200 mmol L-1 NaCl treatment compared with wild-type (WT) plants, and OsARF12 knockout (OsARF12-KO) using CRISPR-Cas9 showed the opposite tendency. Physiological analyses revealed that OsARF12-OX plants mitigated salt-induced oxidative damage by enhancing ROS scavenging capacity and promoting Na+ /K+ homeostasis as well as through their superior photosynthetic efficiency under 200 mmol L-1 NaCl treatment, which was consistent with the upregulation of differentially expressed genes involved in ROS scavenging, photosynthesis and ion transport pathways. Furthermore, auxin receptor genes or transcription inhibitor genes were upregulated or downregulated in OsARF12-OX lines compared with WT plants under salt stress, respectively. Biochemical assays indicated that OsARF12 acts as a transcriptional activator, directly binding to TGTC-box motifs in the promoters of the key ion transporters OsSOS1 and OsHKT1;5 to reduce shoot Na+ content and the Na+/K+ ratio, thereby increasing salt tolerance. These findings revealed the potential role of OsARF12 in increasing salt tolerance by integrating auxin signaling with ROS scavenging, ionic homeostasis and photosynthetic networks, offering valuable targets for breeding resilient rice varieties. (c) 2025 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Fatty acids play a putative role as second messengers of phytohormones and regulate the rice grain weight. However, the inner mechanism is still unclear and needs to be further studied. In this study, we identified that oleic acid (C18:1) negatively correlates while linoleic acid (C18:2) positively correlates with rice grain weight. Field trials showed that 1000-grain weight was significantly reduced when treated with the fatty acid synthesis inhibitor, Firsocostat S enantiomer (FSE), at the heading and flowering stages. RNA-seq analysis revealed that FSE affects grain weight by modulating processes, such as glycolysis, sucrose metabolism, and hormone signaling. Notably, FSE inhibited the expression of OsLIN6, which is responsible for transporting C18:1 to the phosphatidylcholine pool for C18:2 synthesis. Compared with the wild type (WT), the OsLIN6 knockout mutant exhibited a lower grain weight, an increased C18:1 content, and a decreased C18:2 content. Importantly, OsARF12 was shown to bind to the OsLIN6 promoter and activate its expression. In summary, this study highlights the crucial role of the fatty acid synthesis gene, OsLIN6, which was regulated by OsARF12, in rice grain weight determination, thus establishing the molecular link between fatty acid synthesis and auxin signaling.

Forage-grain ratoon rice (FG-RR) systems, integrating grain and forage production, promise a sustainable approach to enhance food security and livestock development in marginal regions where ratoon rice (T-RR) is traditionally cultivated. Here, we quantified zinc (Zn), copper (Cu), arsenic (As), and cadmium (Cd) concentrations in ratoon crop grains from 23 rice varieties at four mowing stages (heading, milk-ripening, dry-ripening, and full maturity) of the main crop. Early mowing at the milk-ripening stage significantly reduced As levels (16.59-46.83 %) and increased Zn (0.61-18.21 %) and Cu (6.81-55.44 %) concentrations, improving nutritional quality. However, Cd levels were elevated (2.10-262.66 %) in FG-RR compared with T-RR. Notably, the impact of mowing stages on the metal concentrations was greater than that of rice varieties. These findings suggest that mowing at the milk-ripening stage enhances the safety and sustainability of FG-RR systems, ensuring improved nutrition and reduced As-related heavy health risks.

China is faced with the contemporaneous needs to improve resource -use efficiency, raise production and enhance environmental stewardship of status quo agrifood production systems. Dual purpose ratoon rice cropping systems comprise a promising innovation for addressing such challenges through production of forage and grain on the same land parcel. Here, we conducted life cycle assessments of forage -grain ratoon rice (FG-RR), contrasting sustainability indicators associated with FG-RR against those of traditional ratoon rice (productivity, environmental impact and economics) across four provinces in central China. Compared with conventional systems, we show that FG-RR systems had superior energy output (+37%) and energy use efficiency (+37%), but also lower global warming potential (-17%) and eutrophication potential (-13%). Such benefits were attributed to lower methane emissions and ammonia volatilization, together with enhanced nitrogen fertilizer management. We found that FG-RR systems had significantly higher productivity, with yields being 6% - 152% greater than traditional production systems, particularly in the climatically challenged areas of Xinyang and Chizhou. We show that biophysical benefits translated to economic dividends, particularly in Chizhou, where net profits were as high as $716 ha -1 . We conclude that FG-RR present a sustainable alternative to traditional rice farming methods, with substantial benefits in terms of production efficiency, environmental sustainability, and economic prosperity. We opine that adoption of FG-RR systems helps address challenges associated with suboptimal productivity, particularly in regions prone to environmental degradation and climatic challenges.

Forage-grain ratoon rice (FG-RR) is a dual-cropping system, with forage harvested in the initial season and grain during the regeneration phase. While it is known that the timing of mowing and nitrogen (N) fertilization are key drivers that influence FG-RR production, physiological mechanisms ensuing mowing and N fertilizer application remain unclear. We conducted field experiments in 2021 and 2022 to investigate the yield and growth characteristics of ratooned crops (RC) under various mowing treatments (heading, milk-ripening, dry-ripening and maturity) using three N levels (135, 270, and 405 kg ha-1), two rice genotypes, Taoyouxiangzhan (TYXZ) and Liangyou 6326 (LY6326). Our results demonstrate a significant increase in ratoon yield when mowing occurred at heading or milk-ripening stages compared with maturity, with a yield increase of 2.2-fold when mowing occurred at heading. Early mowing stages increased stubble biomass (up to 73 %) and non-structural carbohydrate (up to 198 %) compared with that at maturity. Mowing at heading or milk-ripening improved accumulated temperature and light exposure, and when coupled with higher N application (270 kg ha-1 N), amplified ratoon ability to recover. Collectively, these factors raised leaf area index, canopy light interception and biomass. Hierarchical partitioning analysis underscored the substantial yet indirect influence of environmental drivers of ratoon yield, alongside a direct driver of growth, particularly thermal sum. We conclude that mowing at heading and milk-ripening with 270 kg ha-1 N elicits optimal ratoon yield with forage production, although further studies are required to determine how these guidelines vary across environments.

Abstract Background: Selenium (Se) is an essential trace element that has various beneficial effects for human healthy. However, the effects of different selenium sources, treatment methods and concentrations on growth and development, photosynthetic characteristics and antioxidant capacity are still unclear in rice. Results: In this study, three concentrations of three different selenium sources were performed in rice using two treatment methods, respectively. The results showed that selenium treatment can increase the plant height, the 1000 grain weight, the Se content of rice grain, and increased the organic selenium content of rice grain, especially. All the selenium treatments improved the photosynthetic indexes including net photosynthetic rate, transpiration rate, and stomatal conductance, decreased inter-cellular CO2 concentration. The activities of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and glutathione reductase (GR), as well as the content of GSSG (Glutathione oxidized) were increased at different levels after Se treatments, while GSH (Glutathione) decreased. Totally, 32 DEGs related to selenium absorption/endocytosis (including six heat shock 70 kDa protein, one ACD), transport (including four ABC transporters, one SULTR, one LAST, one Inorganic phosphate transporter, one GlpT, one PHO, one PPT) and metabolism (including NAS1, NAS2, APS5, 3MST2, PPCS1, SAMDC and 8 protein kinases), 6 DEGs related to glutathione metabolic pathway (including one G6PD, four GSTs and one GSS), 69 transcription factors (including 19 AP2/ERF-ERFs, 9 MYBs, 9 WRKYs, 8 HSFs, 6 bHLHs, 5 GRASs, 4 NACs,3 B3-ARFs, 3 C2H2s and 3 bZIPs) were identified by RNA-Seq. Conclusion: Our study indicated that exogenous selenium treatments could increase the 1000 grain weight, the Se content and the organic selenium content of rice grain by improving photosynthetic traits and antioxidant enzyme activities, especially sodium selenite. The expressions of the genes related to selenium metabolism indicated that foliar spraying can faster induce the response of Se treatment in rice than root irrigation. The results will provide an insight into the selenium enrichment of rice.

Selenium (Se) is an essential trace element that has various beneficial effects for human healthy. However, the effects of different Se forms and concentrations on growth and development, photosynthetic characteristics and antioxidant capacity are still unclear with regard to the dual grain-and-feed dual-use of ratoon rice (RR). In this study, three concentrations of three different Se forms were applied to RR using the foliar spraying method, and the results showed that Se treatment can increase the Se content of rice grain and straw. All the Se treatments improved the photosynthetic indexes and activities of antioxidant enzymes. The Se and trace elements contents, and the percentages of organic Se and protein Se of brown rice were found to be similar in all three Se forms. A higher organic Se content was found in the grain by spraying sodium selenite and Se-Met, in which the resistant starch (RS) content was increased with the increase in amylose content in grains. The main Se species in the grain was SeMet and the SeMeCys was found only with SeMet treatments. The grain quality showed that all three Se forms increased the consistency of gelatinization. Our study indicated that exogenous Se could improve the nutritional quality of both grain and straw by improving photosynthetic traits and antioxidant enzyme activities, especially sodium selenite and Se-Met. These results underscore the potential of foliar biofortification to enhance the functional component contents of RR grains and provide an insight into the Se enrichment of ratoon rice.