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KAI2 receptors, classified as plant α/β hydrolase enzymes, are capable of perceiving smoke-derived butenolide signals and endogenous yet unidentified KAI2-ligands (KLs). While the number of functional KAI2 receptors varies among land plant species, rice has only one KAI2 gene. Rice, a significant crop and representative of grasses, relies on KAI2-mediated Arbuscular mycorrhiza (AM) symbioses to flourish in traditionally arid and nutrient-poor environments. This study presents the first crystal structure of an active rice (Oryza sativa, Os) KAI2 hydrolase receptor. Our structural and biochemical analyses uncover grass-unique pocket residues influencing ligand sensitivity and hydrolytic activity. Through structure-guided analysis, we identify a specific residue whose mutation enables the increase or decrease of ligand perception, catalytic activity, and signal transduction. Furthermore, we investigate OsKAI2-mediated signaling by examining its ability to form a complex with its binding partner, the F-box protein DWARF3 (D3) ubiquitin ligase and subsequent degradation of the target substrate OsSMAX1, demonstrating the significant role of hydrophobic interactions in the OsKAI2-D3 interface. This study provides new insights into the diverse and pivotal roles of the OsKAI2 signaling pathway in the plant kingdom, particularly in grasses.

P/TGMS (Photo/thermo-sensitive genic male sterile) lines are crucial resources for two-line hybrid rice breeding. Previous studies revealed that slow development is a general mechanism for sterility-fertility conversion of P/TGMS in Arabidopsis. However, the difference in P/TGMS genes between rice and Arabidopsis suggests the presence of a distinct P/TGMS mechanism in rice. In this study, we isolated a novel P/TGMS line, ostms19, which shows sterility under high-temperature conditions and fertility under low-temperature conditions. OsTMS19 encodes a novel pentatricopeptide repeat (PPR) protein essential for pollen formation, in which a point mutation GTA(Val) to GCA(Ala) leads to ostms19 P/TGMS phenotype. It is highly expressed in the tapetum and localized to mitochondria. Under high temperature or long-day photoperiod conditions, excessive ROS accumulation in ostms19 anthers during pollen mitosis disrupts gene expression and intine formation, causing male sterility. Conversely, under low temperature or short-day photoperiod conditions, ROS can be effectively scavenged in anthers, resulting in fertility restoration. This indicates that ROS homeostasis is critical for fertility conversion. This relationship between ROS homeostasis and fertility conversion has also been observed in other tested rice P/TGMS lines. Therefore, we propose that ROS homeostasis is a general mechanism for the sterility-fertility conversion of rice P/TGMS lines.

BACKGROUND: Sulfur (S) is a mineral nutrient essential for plant growth and development, which is incorporated into diverse molecules fundamental for primary and secondary metabolism, plant defense, signaling, and maintaining cellular homeostasis. Although, S starvation response is well documented in the dicot model Arabidopsis thaliana, it is not clear if the same transcriptional networks control the response also in the monocots. RESULTS: We performed series of physiological, expression, and metabolite analyses in two model monocot species, one representing the C3 plants, Oryza sativa cv. kitaake, and second representing the C4 plants, Setaria viridis. Our comprehensive transcriptomic analysis revealed twice as many differentially expressed genes (DEGs) in S. viridis than in O. sativa under S-deficiency, consistent with a greater loss of sulfur and S-containing metabolites under these conditions. Surprisingly, most of the DEGs and enriched gene ontology terms were species-specific, with an intersect of only 58 common DEGs. The transcriptional networks were different in roots and shoots of both species, in particular no genes were down-regulated by S-deficiency in the roots of both species. CONCLUSIONS: Our analysis shows that S-deficiency seems to have different physiological consequences in the two monocot species and their nutrient homeostasis might be under distinct control mechanisms.

BACKGROUND: Development of transgenic rice overexpressing transcription factors involved in drought response has been previously reported to confer drought tolerance and therefore represents a means of crop improvement. We transformed lowland rice IR64 with OsTZF5, encoding a CCCH-tandem zinc finger protein, under the control of the rice LIP9 stress-inducible promoter and compared the drought response of transgenic lines and nulls to IR64 in successive screenhouse paddy and field trials up to the T6 generation. RESULTS: Compared to the well-watered conditions, the level of drought stress across experiments varied from a minimum of - 25 to - 75 kPa at a soil depth of 30 cm which reduced biomass by 30-55% and grain yield by 1-92%, presenting a range of drought severities. OsTZF5 transgenic lines showed high yield advantage under drought over IR64 in early generations, which was related to shorter time to flowering, lower shoot biomass and higher harvest index. However, the increases in values for yield and related traits in the transgenics became smaller over successive generations despite continued detection of drought-induced transgene expression as conferred by the LIP9 promoter. The decreased advantage of the transgenics over generations tended to coincide with increased levels of homozygosity. Background cleaning of the transgenic lines as well as introgression of the transgene into an IR64 line containing major-effect drought yield QTLs, which were evaluated starting at the BC3F1 and BC2F3 generation, respectively, did not result in consistently increased yield under drought as compared to the respective checks. CONCLUSIONS: Although we cannot conclusively explain the genetic factors behind the loss of yield advantage of the transgenics under drought across generations, our results help in distinguishing among potential drought tolerance mechanisms related to effectiveness of the transgenics, since early flowering and harvest index most closely reflected the levels of yield advantage in the transgenics across generations while reduced biomass did not.

INTRODUCTION: Owing to advances in high-throughput genome sequencing, QTL-Seq mapping of salt tolerance traits is a major platform for identifying soil-salinity tolerance QTLs to accelerate marker-assisted selection for salt-tolerant rice varieties. We performed QTL-BSA-Seq in the seedling stage of rice from a genetic cross of the extreme salt-sensitive variety, IR29, and Jao Khao (JK), a Thai salt-tolerant variety. METHODS: A total of 462 F2 progeny grown in soil and treated with 160 mM NaCl were used as the QTL mapping population. Two high- and low-bulk sets, based on cell membrane stability (CMS) and tiller number at the recovery stage (TN), were equally sampled. The genomes of each pool were sequenced, and statistical significance of QTL was calculated using QTLseq and G prime (G) analysis, which is based on calculating the allele frequency differences or Δ(SNP index). RESULTS: Both methods detected the overlapping interval region, wherein CMS-bulk was mapped at two loci in the 38.41-38.85 Mb region with 336 SNPs on chromosome 1 (qCMS1) and the 26.13-26.80 Mb region with 1,011 SNPs on chromosome 3 (qCMS3); the Δ(SNP index) peaks were -0.2709 and 0.3127, respectively. TN-bulk was mapped at only one locus in the overlapping 38.26-38.95 Mb region on chromosome 1 with 575 SNPs (qTN1) and a Δ(SNP index) peak of -0.3544. These identified QTLs in two different genetic backgrounds of segregating populations derived from JK were validated. The results confirmed the colocalization of the qCMS1 and qTN1 traits on chromosome 1. Based on the CMS trait, qCMS1/qTN1 stably expressed 6%-18% of the phenotypic variance in the two validation populations, while qCMS1/qTN1 accounted for 16%-20% of the phenotypic variance in one validation population based on the TN trait. CONCLUSION: The findings confirm that the CMS and TN traits are tightly linked to the long arm of chromosome 1 rather than to chromosome 3. The validated qCMS-TN1 QTL can be used for gene/QTL pyramiding in marker-assisted selection to expedite breeding for salt resistance in rice at the seedling stage.

The rice receptor kinase XA21 confers broad-spectrum resistance to Xanthomonas oryzae pv. oryzae (Xoo), the causal agent of rice bacterial blight disease. To investigate the relationship between the expression level of XA21 and resulting resistance, we generated independent HA-XA21 transgenic rice lines accumulating the XA21 immune receptor fused with an HA epitope tag. Whole-genome sequence analysis identified the T-DNA insertion sites in sixteen independent T0 events. Through quantification of the HA-XA21 protein and assessment of the resistance to Xoo strain PXO99 in six independent transgenic lines, we observed that XA21-mediated resistance is dose dependent. In contrast, based on the four agronomic traits quantified in these experiments, yield is unlikely to be affected by the expression level of HA-XA21. These findings extend our knowledge of XA21-mediated defense and contribute to the growing number of well-defined genomic landing pads in the rice genome that can be targeted for gene insertion without compromising yield.

Millets, historically staple foods in Asia and Africa, saw reduced cultivation and consumption with the rise of wheat, maize, and rice in the mid-20th century. Recognizing their potential, the United Nations declared 2023 as the International Year of Millets (IYOM) to promote their reintroduction into global food systems. Millets offer benefits like climate resilience, balanced nutrition, and gluten-free properties. Consumption can help combat obesity, diabetes, and cholesterol, offering a solution to malnutrition amidst rising populations. Extrusion processing can mass-produce millet-based food products to meet societal needs to provide nutrient-rich, affordable, and shelf-stable products. Leveraging extrusion technology, millet-based products can be efficiently mass-produced to meet nutritional needs, enhancing food security worldwide. Moreover, extrusion causes biochemical changes, such as protein denaturation, starch gelatinization, inactivation of microorganisms, enzymes, anti-nutritional factors, and solubilizes fiber. This review aims to explore millet functionality and extrudability, unlocking possibilities for diverse, nutrient-rich food products. [ABSTRACT FROM AUTHOR]

Seed mycoflora poses significant challenges to rice production, leading to substantial economic losses. Fourteen samples of stored and freshly harvested seeds of five rice varieties were collected from the Agricultural farm of Orissa University of Agriculture and Technology, Bhubaneswar, Odisha, to study the morphology of the mycoflora associated with rice seeds and their impact on seed health and quality. Eight fungal species, including Fusarium pallidoroseum, Fusarium fujikuroi, Curvularia lunata, Helminthosporium oryzae, Trichoconis padwickii, Aspergillus flavus, Rhizopus sp., and Penicillium sp., were isolated, identified, and morphologically characterized based on colony growth, mycelial features, conidial structures, and spore measurements. The rice varieties, viz., Hema, Jyotirmayee, Swarna, Lalat, and Annapurna, were artificially inoculated with F. pallidoroseum, F. fujikuroi, T. padwickii, C. lunata, and H. oryzae. Seeds showed that the fungi had a variable effect on seed quality parameters like germination, seedling vigor index I and seedling vigor index II, speed of germination, and seed health. A maximum of 16.33% reduction of germination was observed by T. padwickii, followed by F. fujikuroi (14.80% in Hema). Seedling vigor (1754.81) incited by T. padwickii inoculation was recorded to be the lowest. Seed rot up to 15.8% was observed in the case of F. fujikuroi. The percentage of root discoloration reached 40.0% by F. pallidoroseum and T. padwickii. In Jyotirmayee, C. lunata caused an 18.88% germination reduction and the lowest seedling vigor (1866.03) by T. padwickii. T padwickii also caused the highest reduction of seedling dry weight (36.12%) in this variety. The result reveals the diversity and prevalence of fungal pathogens in rice seeds. Hence, this study underscores the importance of seed sterilization practices in reducing fungal contamination and the requirement of thorough seed examination to reduce the effects of seed mycoflora associated with rice seeds, which could affect rice production. [ABSTRACT FROM AUTHOR]

SUMMARY Lesion‐mimic mutants (LMMs) serve as valuable resources for uncovering the molecular mechanisms that govern programmed cell death (PCD) in plants. Despite extensive research, the regulatory mechanisms of PCD and lesion formation in various LMMs remain to be fully elucidated. In this study, we identified a rice LMM named early leaf lesion and senescence 1 (els1), cloned the causal gene through map‐based cloning, and confirmed its function through complementation. ELS1 encodes an anthranilate synthase α‐subunit involved in anthranilate biosynthesis. It is predominantly localized in chloroplasts and is primarily expressed in light‐exposed tissues. Mutation of ELS1 triggers upregulation of its homologous gene, ASA1, via a genetic compensation response, leading to the activation of the tryptophan (Trp) synthesis pathway and amino acid metabolism. The accumulation of abnormal Trp‐derived intermediate metabolites results in reactive oxygen species (ROS) production and abnormal PCD in the els1 mutant, ultimately causing the leaf lesion phenotype. The els1 mutant also exhibits reduced chlorophyll content, upregulation of genes related to chloroplast degradation and leaf senescence, and decreased activity of photosynthetic proteins, indicating that ELS1 plays a role in chloroplast development. These factors collectively contribute to the premature leaf senescence observed in the els1 mutant. Our findings shed light on the role of ELS1 in regulating ROS accumulation and PCD in rice, providing further genetic insights into the molecular mechanisms governing leaf lesions and senescence. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa L.) is the extensively consumed primary food with a main source of energy, vitamins, minerals, fiber, and biomolecules. It is not only a dietary cornerstone but also has an array of bioactive compounds with significant health benefits. The use of rice ingredients in dietary supplements, culinary additives, pharmacological adjuvants, and nutritional products is growing. Therefore, this review article summarized the rice biomolecules, its utilization in various diets and food products, and therapeutic properties of rice. The article concluded that rice grain emerges as a potential source of phytochemicals like oryzanol, phenolics, anthocyanins, flavonoids, carotenoids, Saponins, vitamin E, and other components with multiple health effects. The article gives information on the application of rice in various food products including bread, cake, vermicelli, pasta, noodles, probiotic beverages, and many more, which are considered to be beneficial for health. Moreover, rice and its bioactive compounds have numerous health benefits like hepatoprotective, anti-inflammatory, neuroprotective, hypolipidemic, hypocholestrolemic, metabolic regulatory effects, protection from cardiovascular diseases, and obesity. Also, the utilization of rice in food and pharmaceutical industry will be increase due to its role in healthy product development, and disease prevention. [ABSTRACT FROM AUTHOR]

Phosphorus (P) deficiency is a major constraint to rice productivity worldwide. Exogenous application of abscisic acid (ABA) has not been reported to improve rice response toward P-deficiency. Present study analyzed the biochemical response in the shoots and roots of two rice cultivars, CSR10 (low-P tolerant) and Pusa44 (low-P susceptible) at 36, 72 and 216 h after normal P (NP) (10 ppm) (control), low P (LP) (1 ppm), and LP + ABA given to 12-d old seedlings. Results found that biomass and P-uptake reduced in Pusa44 compared to CSR10 under LP but improved significantly under LP + ABA. P-fractionation was utilized efficiently by CSR10 under LP while LP + ABA improved P-fractionation in both cultivars. LP + ABA improved acid phosphatases in both cultivars. Hexose and sucrose levels were depleted while starch hydrolyzed poorly in Pusa44 compared to CSR10 under LP while LP + ABA enhanced starch hydrolysis and levels of sugars in both cultivars. Starch increased at a late stage in the roots of CSR10 under LP while Pusa44 improved it under LP + ABA. Antioxidant capacity was low while H2O2 was high at early stage in Pusa44 compared to CSR10 under LP. LP + ABA improved antioxidant capacity and reduced H2O2 in both cultivars. Results concluded that ABA is a versatile regulator of not only P-acquisition/P-utilization but also carbohydrates and antioxidant activities under P-deficiency, and exogenous ABA improved low-P tolerance in rice. [ABSTRACT FROM AUTHOR]

The significance of zinc and iron in crop production, particularly in rice-wheat cropping systems, has been increasingly recognized. The present study aimed to determine the effect of different soil samples collected from the rice-wheat cropping system of Haryana with different soil texture on rice grain yield and micronutrient content using a greenhouse trial with four levels of Fe (0, 25, 50 mg kg−1 as soil and 0.5% foliar spray of FeSO4 at 45 DAS) and four levels of Zn (0, 5, 10 mg kg−1 as soil and 0.5% foliar spray of ZnSO4 at 35 DAS). This study discovered that rice grain yield showed a positive correlation with soil Zn and Fe concentrations in soil before sowing and a negative correlation with soil Fe and Zn concentrations in soil after crop harvesting. In most of the soils studied, foliar spray alone Fe @ 0.5% foliar (45 DAS) and Zn @ 0.5% foliar (35 DAS) improved Fe and Zn concentrations in rice significantly more than soil application of 25 mg Fe kg−1 and 5 mg Zn kg−1, respectively. The rice grain yield in clay soil was 14-42% higher than in sandy soil with different doses of Zn and Fe application. The order of preponderance of different Fe and Zn fractions were CA-Fe < OM-Fe < EX-Fe < FeMnOX-Fe < Res-Fe and Res-Zn > FeMnOX-Zn > OM-Zn > CA-Zn > Ex-Zn in the soils, respectively. Conclusively, concomitant consideration of grain yield and grain Zn and Fe concentrations of rice are the sustainable approach toward food targets achievement. [ABSTRACT FROM AUTHOR]

Summary Flooding is a widespread natural disaster that causes tremendous yield losses of global food production. Rice is the only cereal capable of growing in aquatic environments. Direct seeding by which seedlings grow underwater is an important cultivation method for reducing rice production cost. Hypoxic germination tolerance and root growth in waterlogged soil are key traits for rice adaptability to flooded environments. Alternative oxidase (AOX) is a non‐ATP‐producing terminal oxidase in the plant mitochondrial electron transport chain, but its role in hypoxia tolerance had been unclear. We have discovered that AOX1a is necessary and sufficient to promote germination/coleoptile elongation and root development in rice under flooding/hypoxia. Hypoxia enhances endogenous H2O2 accumulation, and H2O2 in turn activates an ensemble of regulatory genes including AOX1a to facilitate the conversion of deleterious reactive oxygen species to H2O2 in rice under hypoxia. We show that AOX1a and H2O2 act interdependently to coordinate three key downstream events, that is, glycolysis/fermentation for minimal ATP production, root aerenchyma development and lateral root emergence under hypoxia. Moreover, we reveal that ectopic AOX1a expression promotes vigorous root and plant growth, and increases grain yield under regular irrigation conditions. Our discoveries provide new insights into a unique sensor–second messenger pair in which AOX1a acts as the sensor perceiving low oxygen tension, while H2O2 accumulation serves as the second messenger triggering downstream root development in rice against hypoxia stress. This work also reveals AOX1a genetic manipulation and H2O2 pretreatment as potential targets for improving flooding tolerance in rice and other crops. [ABSTRACT FROM AUTHOR]

ABSTRACT Understanding the reciprocal interaction between root development and coadapted beneficial microbes in response to elevated CO2 (eCO2) will facilitate the identification of nutrient‐efficient cultivars for sustainable agriculture.Here, systematic morphological, anatomical, chemical and gene expression assays performed under low‐nitrogen conditions revealed that eCO2 drove the development of the endodermal barrier with respect to L‐/S‐shaped lateral roots (LRs) in rice.Next, we applied metabolome and endodermal‐cell‐specific RNA sequencing and showed that rice adapts to eCO2 by spatially recruiting diazotrophs via flavonoid secretion in L‐shaped LRs. Using the rice Casparian strip mutant Oscasp1‐1, we confirmed that reduced lignin deposition selectively recruits the diazotrophic family of Oxalobacteraceae to confer tolerance to low nitrogen availability. [ABSTRACT FROM AUTHOR]

Introduction: Genetic improvement in rice increased yield potential and improved varieties for farmers over the last decades. However, the demand for rice is growing while its cultivation faces challenges posed by climate change. To address these challenges, rice breeding programs need to adopt efficient breeding strategies to provide a steady increase in the rate of genetic gain for major traits. The International Rice Research Institute (IRRI) breeding program has evolved over time to implement faster and more efficient breeding techniques such as rapid generation advance (RGA) and genomic selection (GS). Simulation experiments support data-driven optimization of the breeding program toward the desired rate of genetic gain for key traits. Methods: This study used stochastic simulations to compare breeding schemes with different cycle times. The objective was to assess the impact of different genomic selection strategies on medium- and long-term genetic gain. Four genomic selection schemes were simulated, representing the past approaches (5 years recycling), current schemes (3 years recycling), and two options for the future schemes (both with 2 years recycling). Results: The 2-Year within-cohort prediction scheme showed a significant increase in genetic gain in the medium-term horizon. Specifically, it resulted in a 22%, 24%, and 27% increase over the current scheme in the zero, intermediate, and high genotype-by-environment interaction (GEI) contexts, respectively. On the other hand, the 2-Year scheme based on between-cohort prediction was more efficient in the long term, but only in the absence of GEI. Consistent with our expectations, the shortest breeding schemes showed an increase in genetic gain and faster depletion of genetic variance compared to the current scheme. Discussion: These results suggest that higher rates of genetic gain are achievable in the breeding program by further reducing the cycle time and adjusting the target population of environments. However, more attention is needed regarding the crossing strategy to use genetic variance optimally. [ABSTRACT FROM AUTHOR]

[Objective]To explore the effect of disturbance gaps on the detection accuracy of capacitive rice moisture sensors. [Method]A rice capacitance analysis model was developed and validated using the Ansoft Maxwell electrostatic field analysis module. Simulation experiments were conducted on parallel, coaxial, and planar capacitive rice moisture sensors based on the model. [Result]Within the moisture content range of 11. 39% to 30. 30%, the apparent dielectric constant of rice grains increased with moisture content, with an average variation ranging from 5. 74 to 41. 13. The relative error of the rice capacitance analysis model was less than 5%, the model’s effectiveness was confirmed. Simulation experiments revealed that larger disturbance gaps lead to greater moisture detection errors. With the same disturbance gap, higher moisture content resulted in higher detection errors. Disturbance gaps located in different positions affected detection differently, with areas of dense electric field lines in capacitors exhibiting larger errors;moreover, simulation experiments identified patterns in the distribution of average detection tolerances across three types of capacitive rice moisture sensors, indicating that parallel plate sensors were least affected by disturbance gaps, followed by coaxial plates, and planar plates were most affected. [Conclusion]The research results have reference significance for optimizing the design of capacitive grain moisture sensors, reducing detection errors due to disturbance gaps and enhancing both accuracy and reliability. [ABSTRACT FROM AUTHOR]

In order to explore the response of rice growth, development, and nutritional characteristics to zinc fertilizer in the Yangzi River Basin. Field experiment with four plots were set up with no fertilizer (CK), farmers’ customary fertilizer practice (FFP) and zinc fertilizer (ZnSO4 7H2O) of 20 and 40 kg / hm2 (FFP+Zn20, FFP+Zn40) based on FFP to study the effects of zinc fertilizer on rice growth, yield, and nutrient absorption. The results showed that compared with FFP, FFP+Zn20 and FFP+Zn40 increased 1 000-grain weight and seed-setting rate of rice,with FFP+Zn40 achieving a significant increase in the 1 000-grain weight and seed-setting rate(P<0. 05). The yield and net benefit of FFP+Zn40 were the highest in the four treatments, increasing significantly by 14. 5% and 15. 6% compared with FFP. The combined application of N and Zn is beneficial for the increase of N and Zn content in the leaves, stems, sheaths, and panicles of rice at maturity, with FFP+ Zn40 having the highest increase. Increasing the application of zinc fertilizer is beneficial for increasing yield, income, and quality of rice in the region. The application of N,P2O5,and K2O at 164, 54, 126 kg / hm² respectively, combined with the application of ZnSO4·7H2O at 40 kg / hm² in the base fertilizer soil, has the best effect. [ABSTRACT FROM AUTHOR]

The roles of plant-specific transcription factor family YABBY may vary among different members. OsYABBY6 is a rice YABBY gene, whose function is not well elucidated so far. In this paper, we show that OsYABBY6 is a nucleus-localized protein with transcriptional activation activity. OsYABBY6 is predominantly expressed in the palea and lemma, as well as in the sheath, culm and node. OsYABBY6 RNA interference (RNAi) plants exhibited altered plant height and larger grain size. Under cold treatment, OsYABBY6 overexpression (OE) plants had up-regulated expression of cold responsive genes, and accumulated less reactive oxygen species but more proline compared to wild type, resulting in improved cold tolerance. On the other hand, RNAi plants showed enhanced drought tolerance compared to the wild type by slower water loss, less reactive oxygen species but more proline and soluble sugar accumulation. In addition, endogenous abscisic acid (ABA) level was reduced in OsYABBY6 RNAi plants, and RNAi and OE plants were more and less sensitive to ABA treatment, respectively. Accordingly, we deduce that OsYABBY6 positively regulates cold response but negatively regulates drought response through different pathways. Our study reveals the crucial roles of OsYABBY6 in plant architecture and grain development, as well as in abiotic stress response, providing new insights into the functions of YABBYs in rice. [ABSTRACT FROM AUTHOR]

ABSTRACT A critical requirement for exploiting heterosis is the production of an adequate number of male‐sterile female plants that will be further used for production of hybrid F1 seeds by outcrossing with the fertile male parent. Seed production technology (SPT) is a recently developed technology that enables mass production of male‐sterile female parents. SPT is constructed by transformation of a recessive nuclear male‐sterile mutant with a transgenic cassette consisting of three functional modules: a wild‐type gene to restore the fertility of the male‐sterile mutant, a pollen‐killer gene to destroy the pollen grains carrying the transgene and a seed marker gene to distinguish the transgenic seeds from the non‐transgenic seeds. Previous research demonstrated that the maize α‐amylase gene (ZM‐AA1), when linked to the maize polygalacturonase gene (PG47) promoter and brittle‐1 gene (BT1) signal peptide, can effectively disrupt pollen fertility by preventing the starch granule formation in pollen grains. To identify additional amylase genes that can be used for construction of the SPT system in rice, we conducted a BLAST search for amylase genes in rice and maize and tested three candidates: the rice amylase gene OsAA1, OsAA2 and the maize amylase gene ZM‐AA2. We found that OsAA1 and ZM‐AA2, when linked to the PG47 promoter and BT1 signal peptide, were capable of destroying transgenic pollen grains, while OsAA2 lacked this function. Bioinformatics analyses, including protein domain, sequence conservation and phylogenetic studies, revealed that OsAA1 and ZM‐AA2 share structural similarity with ZM‐AA1 whereas OsAA2 exhibited significant differences from ZM‐AA1 in structure and sequence. OsAA1 and ZM‐AA2 identified in this study provide valuable tools for genetic engineering of rice male sterility systems for hybrid rice breeding and production. [ABSTRACT FROM AUTHOR]

While it is known that temperature sensors trigger calcium (Ca2+) signaling to confer cold tolerance in cells, less is known about sensors that couple with other secondary messengers. Here, we identify a cold sensor complex of CHILLING-TOLERANCE DIVERGENCE 6 (COLD6) and osmotin-like 1 (OSM1), which triggers 2′,3′-cyclic adenosine monophosphate (2′,3′-cAMP) production to enhance cold tolerance in rice. COLD6, which is encoded by a major quantitative trait locus (QTL) gene, interacts with the rice G protein α subunit (RGA1) at the plasma membrane under normal conditions. Upon exposure to chilling, cold-induced OSM1 binds to COLD6, kicking out RGA1 from interaction. This triggers an elevation of 2′,3′-cAMP levels for enhancing chilling tolerance. Genetic data show that COLD6 negatively regulates cold tolerance and functionally depends on OSM1 in chilling stress. COLD6 alleles were selected during rice domestication. Knockout and natural variation of COLD6 in hybrid rice enhanced chilling tolerance, hinting design potential for breeding. This highlighted a module triggering 2′,3′-cAMP to improve chilling tolerance in crops. [Display omitted] • A major QTL, COLD6 , negatively regulates cold tolerance in rice • COLD6 is associated with environmental adaptation during rice domestication • COLD6 interacts with osmotin-like 1 (OSM1) protein for cold tolerance • COLD6-OSM1 module triggers 2′,3′-cAMP signaling, enhancing cold tolerance in rice While roles for Ca2+ signaling in cold tolerance are known, less is known about sensors coupled with other secondary messengers. Luo et al. identify a chilling sensor complex COLD6, encoded by a major QTL gene, and OSM1, which triggers 2′,3′-cAMP signaling to enhance cold tolerance in rice. [ABSTRACT FROM AUTHOR]

The editorial in "Frontiers in Plant Science" explores the molecular interactions between plants and insects, focusing on defense mechanisms and resistance genes. The research delves into the complex genetic and metabolic processes involved in plant-insect interactions, using advanced omics technologies. Specific studies highlighted in the editorial include the interaction between rice and the brown planthopper, as well as aphid-mediated tritrophic interactions and psyllid-pathogen interactions. The articles provide valuable insights into the molecular arms race between plants and insects, aiming to enhance pest control strategies and sustainable crop production. [Extracted from the article]

Plant growth-promoting rhizobacteria colonize the rhizosphere through dynamic and intricate interactions with plants, thereby providing various benefits and contributing to plant growth. Moreover, increasing evidence suggests that plant growth-promoting rhizobacteria affect plant tolerance to abiotic stress, but the underlying molecular mechanisms remain largely unknown. In this study, we investigated the effect of Bacillus velezensis strain GH1-13 on drought stress tolerance in rice. Phenotypical analysis, including the measurement of chlorophyll content and survival rate, showed that B. velezensis GH1-13 enhances rice tolerance to drought stress. Additionally, visualizing ROS levels and quantifying the expression of ROS-scavenging genes revealed that GH1-13 treatment reduces ROS accumulation under drought stress by activating the expression of antioxidant genes. Furthermore, the GH1-13 treatment stimulated the jasmonic acid response, which is a key phytohormone that mediates plant stress tolerance. Together with the result that jasmonic acid treatment promotes the expression of antioxidant genes, these findings indicate that B. velezensis GH1-13 improves drought tolerance in rice by reducing ROS accumulation and suggest that activation of the jasmonic acid response is deeply involved in this process. [ABSTRACT FROM AUTHOR]

Drought and salinity are significant challenges to global food security. This study investigated the interactive impacts of Piriformospora indica inoculation with salinity and drought stresses on rice. Two greenhouse experiments were conducted. The first experiment evaluated two P. indica inoculation levels and three salinity levels (0-, 50-, and 100-mM sodium chloride), while the subsequent experiment assessed two inoculation levels under three drought intensities (25%, 50%, and 100% of available water content). P. indica spores were inoculated following optimized seed disinfection and germination processes. The shoot and root biomass under salinity stress were consistently higher in inoculated plants compared to controls. Sodium concentrations in shoots and roots exhibited an overall upward trend, with the trend being less pronounced in inoculated plants due to increased potassium uptake. Under salinity stress, nitrogen, magnesium, and calcium concentrations significantly increased in inoculated plants. With increasing salinity, there was a significant increase in catalase enzyme activity and soluble carbohydrate concentrations across all treatments, with a greater increase in inoculated plants. Plants under drought stress experienced reduced root and shoot biomass, but inoculated plants maintained higher biomass. Increasing drought stress led to decreased nitrogen, magnesium, and calcium concentrations in all treatments, with the reduction being less severe in inoculated plants. Catalase enzyme activity and carbohydrate increased with rising drought stress, with the increase being more pronounced in inoculated plants compared to non-inoculated ones. By promoting plant growth, nutrient uptake, and stress tolerance, P. indica inoculation has a significant potential to enhance crop productivity in extreme climate conditions. [ABSTRACT FROM AUTHOR]

Crop resistance to herbicides is crucial for agricultural productivity and sustainability amidst escalating challenges of weed resistance. Uncovering herbicide resistant genes is particularly important for rice production. In this study, we tested the resistance to three commonly used herbicides: glufosinate, glyphosate and mesotrione of 421 diverse rice cultivars and employed genome-wide association studies (GWAS) to unravel the genetic underpinnings of resistance to these three herbicides in rice. We discovered that cultivated rice exhibited rich variation in resistance to the three herbicides, and the differences among subpopulations were significant. Six identified associations harboring candidate genes for resistance to these herbicides were significant. Among them, RGlu6 and RGly8 were the major QTL for resistance to glufosinate and glyphosate, respectively. The favorable alleles of RGlu6 and RGly8 were primarily present in japonica cultivars that originated from Europe, highlighting the geographic and genetic diversity of herbicide resistance and emphasizing the localized selection pressures in European rice varieties. Moreover, our findings might suggest that traditional target genes may not contain tolerant alleles in nature, and alternative mechanisms with novel loci associated with resistance may work. By mapping the genes for herbicide resistance, our results may help develop new strategies to combat the dual challenges on effective weed management and herbicide sustainability. [ABSTRACT FROM AUTHOR]

The glycolytic enzyme cytoplasmic glyceraldehyde-3-phosphate dehydrogenase (GAPC3) is involved in multiple biological processes in plants, including transcriptional regulation, and material metabolism. However, the relationship between OsGAPC3 and the quality traits of rice is poorly understood. Here we identify OsGAPC3 mutations that enhance the protein content and grain nutritional quality of rice by regulating the OsAAP6 gene expression. The number and volume of type-II protein bodies in the endosperm of the OsGAPC3 mutants, and GPC increase significantly. We report significant increases in chalkiness area and degree, and decreases for starch content, gel consistency, and taste value. Results of proteomic detection and analysis reveal that OsGAPC3 affects the major storage substances (proteins and starch) metabolism in rice, and the accumulation of proteins and starch in the endosperm. Additionally, the OsGAPC3 mutation significantly decreases the rice-seedling salt tolerance. Therefore, OsGAPC3 affects multiple quality traits of rice, participates in regulating rice-seedling salt-stress response. These data can be used to design better-quality and stronger salt-resistant rice varieties. [ABSTRACT FROM AUTHOR]

Introduction: Selenium is an essential micronutrient the human body requires, which is closely linked to health. Rice, a primary staple food globally, is a major source of human selenium intake. To develop selenium-enriched rice varieties, it is imperative to understand the mechanisms behind selenium's absorption and transport within rice, alongside identifying the key genes involved in selenium uptake, transport, and transformation within the plant. Methods: This study conducted transcriptome sequencing on four types of rice materials (two with low-selenium and two with high-selenium contents) across roots, stems, leaves, and panicles to analyze the gene expression differences. Results and discussion: Differential gene expression was observed in the various tissues, identifying 5,815, 6,169, 7,609, and 10,223 distinct genes in roots, stems, leaves, and panicles, respectively. To delve into these differentially expressed genes and identify the hub genes linked to selenium contents, weighted gene co-expression network analysis (WGCNA) was performed. Ultimately, 10, 8, 7, and 6 hub genes in the roots, stems, leaves, and panicles, respectively, were identified. The identification of these hub genes substantially aids in advancing our understanding of the molecular mechanisms involved in selenium absorption and transport during the growth of rice. [ABSTRACT FROM AUTHOR]

Rotational shifting cultivation (RSC) is commonly practiced in northern Thailand for upland rice cultivation, primarily for household consumption. However, the potential health risks from heavy metal contamination in these soils have not been thoroughly explored. This study aimed to evaluate the contamination of six heavy metals (Arsenic (As), Mercury (Hg), Cadmium (Cd), Lead (Pb), Copper (Cu), and Chromium (Cr)) in upland rice across RSC fields with varying fallow periods and assess the associated health risks from rice consumption. Four RSC fields with 5, 6, 10, and 12-year fallow periods were examined. The RSC-6Y and RSC-12Y fields were used for upland rice cultivation in 2022, while the RSC-5Y and RSC-10Y fields were cultivated in 2023. The geo-accumulation index (Igeo) was calculated, and translocation factors (TF) were assessed for the transfer of heavy metals from soil to straw (TFStraw/Soil), straw to grain (TFGrain/Straw), and soil to grain (TFGrain/Soil). The results indicated that after burning vegetation in the RSC fields, the highest concentrations of Pb, Cr, and Hg were found in the ash. In RSC soils, Cu, Cr, As, Pb, and Hg levels were below reference standards, with Cd undetected. In rice grains, the order of concentration was Pb > Cu > Cr > As, with Hg and Cd undetected. Pb levels in rice grains exceeded the safety threshold. Igeo values indicated no contamination to moderate contamination across sites, with negative Igeo values for Cr and Cu, and zero values for Cd. The TF results showed limited transfer of As, Hg, and Cd from soil to rice plants (TFStraw/Soil < 0.1), but notable transfer for Pb, Cr, and Cu. Pb was readily transferred from soil to grain (TFGrain/Soil), posing a potential health risk. The study highlights potential non-carcinogenic and carcinogenic risks from heavy metal exposure, particularly Pb, and underscores the need for further research to determine contamination sources and mitigation strategies. [ABSTRACT FROM AUTHOR]

Background: The extent of natural salt-laden groundwaters used for irrigation is increasing worldwide, which is a fast-emerging threat to agroecosystems and global food security. The salt buildup in the soil is linked to deteriorated soil chemical, physical, and biological health and decreased land productivity. Alkali waters with high residual sodium carbonate (RSC) is one of the severe poor-quality waters that deteriorate soil. We evaluated soil microbial dynamics and soil health at critical growth stages of rice crop receiving two-decade-long irrigation with three levels of alkali water and two reclamation strategies. These included good-quality water (GQW), alkali water (ALKW) with an RSC concentration of 5 me L⁻1 (ALKW1), ALKW with an RSC concentration of 10 me L⁻1 (ALKW2), ALKW2 treated to neutralize RSC to 5 me L⁻1 using gypsum (CaSO4·2H2O; ALKW2 + GYP), and ALKW2 treated with sulfuric acid (H2SO4; ALKW2 + SA). Eleven microbial parameters were used to develop a soil microbial activity index (SMAI), and eight soil health indicators were correlated with changes in SMAI and crop productivity. Results: The SMAI peaked under good-quality water (GQW) conditions (0.84–0.89), while the lowest values were recorded under ALKW2 (0.06–0.18). Neutralized alkali waters, ALKW2 + SA and ALKW2 + GYP, significantly improved SMAI with corresponding values of 0.25–0.35 and 0.13–0.32, respectively. SMAI across all stages correlated positively (R2 = 0.91–0.98) with rice yield. Microbial activity varied with the crop growth stage, peaking at tillering. Gypsum application alone, aimed at neutralizing alkalinity from an RSC of 10 to 5 me L⁻1, proved insufficient in bringing the SMAI up to the ALKW1 (RSC level of 5 me L⁻1). Conclusions: The application of dilute sulfuric acid demonstrated better results in restoring the soil microbial activity index than gypsum amendment; however, sulfuric acid treatment depends on native calcium carbonate (CaCO3) dissolution for its effectiveness. It may not suffice for soil stability improvement in the long term, especially when native CaCO3 is low. Therefore, integrating gypsum and dilute sulfuric acid for RSC neutralization is worthwhile; however, further assessment is needed to confirm their combined impact on soil biochemical and physical properties. [ABSTRACT FROM AUTHOR]

Replacing chemical nitrogen (N) fertilizer with monosodium glutamate waste liquid residue (MSGWLR) is beneficial for achieving clean production in both the monosodium glutamate (MSG) industry and agriculture. However, the impact of this method on rice production and environment has not yet been clear. This study adopted field experiments to clarify the rice yield, quality and carbon emissions applying conventional application of chemical N fertilizer (CF), reduction of N fertilizer by 20% (N80%), based on reduction of chemical N fertilizer by 20% and replacing 50% chemical N fertilizer with MSGWLR (MSGWLR50%), and replacing 100% chemical N fertilizer (MSGWLR100%). The results showed that compared with CF treatment, MSGWLR100% showed no significant changes in rice yield, milling quality, fatty acid value, and taste quality. The chalkiness rate of rice significantly decreased, and the protein content significantly increased. On the other hand, the carbon emissions from rice production treated with MSGWLR100% were the lowest, with a 58.5% decrease in global warming potential (GWP) compared to CF treatment. This was mainly because MSGWLR100% treatment could provide rich and balanced nutrients for rice growth, and it did not promote greenhouse gas (GHG) emissions from paddy field. At the same time, it effectively reduced the indirect carbon emissions in chemical fertilizer production by reducing chemical N fertilizer. Therefore, the MSGWLR100% fertilization treatment is beneficial for cleaner production in the MSG industry and rice cultivation. Highlights: • MSGWLR could effectively replace chemical N fertilizer while maintaining rice yield. • Both MSGWLR50% and MSGWLR100% treatments successfully maintained rice quality. • Replacing chemical N fertilizer with MSGWLR significantly reduced carbon emissions from rice production. [ABSTRACT FROM AUTHOR]

Background: Nilaparvata lugens is one of the most destructive pests of rice. RNAi-based N. lugens control offers one alternative strategy to traditional chemical insecticides. However, selection of potential target for RNAi against N. lugens remains a major challenge. Only two target genes for nuclear transgenic N. lugens-resistant plants have been screened. Importantly, only one or few potential target genes against N. lugens were screened every time by knowledge of essential genes from model organisms in previous study. Results: Here, in silico genome-wide selection of potential target genes against N. lugens through homology comparison was performed. Through genome synteny comparisons, about 3.5% of Drosophila melanogaster genome was found to have conserved genomic synteny with N. lugens genome. By using N. lugens proteins to search D. melanogaster homologs defining lethal or sterile phenotype, 358 N. lugens genes were first screened as putative target genes. Transgenic rice lines expressing dsRNA of randomly selected gene (NlRan or NlSRP54) from 358 putative target genes enhanced resistance to N. lugens. After expression check and safety check, 115 N. lugens genes were screened as potential target candidates. Conclusion: The combined efforts in this study firstly provide one in silico genome-wide homology-based screening approach for RNAi-based target genes against N. lugens, which not only offer one new opportunity to batch select potential target candidates in pests of interest, but also will facilitate the selection of RNAi target in many pest species by providing more than one hundred potential target candidates. [ABSTRACT FROM AUTHOR]

Phosphatidylinositol signaling system plays a crucial role in plant physiology and development, phosphatidylinositol phosphate kinases (PIPKs) are one of the essential enzymes responsible for catalyzing the synthesis of phosphatidylinositol bisphosphate (PIP2) within this signaling pathway. However, its mechanism of signal transduction remains poorly exploited in plants. OsMBL1, a jacalin-related mannose-binding lectin in rice, plays a crucial role in plant defense mechanisms, acting as a key component of the pattern-triggered immunity (PTI) pathway. Here, a rice phosphatidylinositol-phosphate kinase FAB (OsPIPK-FAB), a member of the rice PIPKs family, as an interacting protein of OsMBL1 through yeast-two-hybrid (Y2H) screening assay. And this interaction was confirmed by using co-immunoprecipitation (Co-IP) and pull-down assay techniques. Furthermore, we demonstrated that the deletion of OsPIPK-FAB gene in plant enhanced resistance against rice blast while overexpression of OsPIPK-FAB increases sensitivity to the fungal infection. Additionally, through determination and measurement of the plant inositol 1,4,5-trisphosphate (IP3) contents and the plant phosphatidylinositol 4-phosphate 5-kinase (PIP5K) activity, we revealed that OsMBL1 inhibits the PIP5K kinase activity of OsPIPK-FAB as well as the plant IP3 contents in rice. Conclusively, these findings indicated that OsPIPK-FAB serves as a novel and critical component that is negatively involved in PTI activation and was inhibited by OsMBL1. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa L.) is susceptible to various abiotic stresses, such as salt, cold, and drought. Therefore, there is an urgent need to explore the relevant genes that enhance tolerance to these stresses. In this study, we identified a gene, OsNCED4 (9-cis-epoxycarotenoid dioxygenase 4), which regulates tolerance to multiple abiotic stresses. OsNCED4 encodes a chloroplast-localized abscisic acid (ABA) biosynthetic enzyme. The expression of OsNCED4 gene was significantly induced by 150 mM NaCl and cold stress. Disruption of OsNCED4 by CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas9-mediated mutagenesis resulted in significant sensitivity to NaCl and cold stress. The salt and cold sensitivity of osnced4 mutant was due to the reduction of ABA content and the excessive accumulation of reactive oxygen species (ROS) under stress. Moreover, OsNCED4 also regulates drought stress tolerance of rice seedlings. Taken together, these results indicate that OsNCED4 is a new regulator for multiple abiotic stress tolerance in rice, and provided a potential target gene for enhancing multiple stress tolerance in the future. [ABSTRACT FROM AUTHOR]

SUMMARY Plasmodesmata (PD) are nanochannels that facilitate cell‐to‐cell transport in plants. More productive and photosynthetically efficient C4 plants form more PD at the mesophyll (M)‐bundle sheath (BS) interface in their leaves than their less efficient C3 relatives. In C4 leaves, PD play an essential role in facilitating the rapid metabolite exchange between the M and BS cells to operate a biochemical CO2 concentrating mechanism, which increases the CO2 partial pressure at the site of Rubisco in the BS cells and hence photosynthetic efficiency. The genetic mechanism controlling PD formation in C3 and C4 leaves is largely unknown, especially in monocot crops, due to the technical challenge of quantifying these nanostructures with electron microscopy. To address this issue, we have generated stably transformed lines of Oryza sativa (rice, C3) and Setaria viridis (setaria, C4) with fluorescent protein‐tagged PD to build the first spatiotemporal atlas of leaf pit field (cluster of PD) density in monocots without the need for electron microscopy. Across leaf development, setaria had consistently more PD connections at the M‐BS wall interface than rice while the difference in M‐M pit field density varied. While light was a critical trigger of PD formation, cell type and function determined leaf pit field density. Complementary temporal mRNA sequencing and gene co‐expression network analysis revealed that the pattern of pit field density correlated with differentially expressed PD‐associated genes and photosynthesis‐related genes. PD‐associated genes identified from our co‐expression network analysis are related to cell wall expansion, translation and chloroplast signalling. [ABSTRACT FROM AUTHOR]

Summary It is urgent to mine novel blast‐resistant genes in rice and develop new rice varieties with pyramiding blast‐resistant genes. In this study, a new blast‐resistant gene, OsBRW1, was screened from a set of rice near‐isogenic lines (NILs) with different blast‐resistant ability. Under the infection of Magnaporthe oryzae (M. oryzae), OsBRW1 in the resistant NIL Pi‐4b was highly induced than that in the susceptible NIL Pi‐1 and their parent line CO39, and the blast‐resistant ability of OsBRW1 was further confirmed by using CRISPR/Cas9 knockout and over‐expression methods. The protein encoded by OsBRW1 was a typical NBS‐LRR with NB‐ARC domain and localized in both cytoplasm and nucleus, and the transient expression of OsBRW1 was capable of triggering hypersensitive response in tobacco leaves. Protein interaction experiments showed that OsBRW1 protein directly interacted with OsSRFP1. At the early infection stage of M. oryzae, OsBRW1 gene induced OsSRFP1 to highly expression level and accumulated H2O2, up‐regulated the defence responsive signalling transduction genes and the pathogenesis‐related genes and increased JA and SA content in the resistant NIL Pi‐4b. By contrary, lower content of endogenous JA and SA in osbrw1 mutants was found at the same stage. After that, OsSRFP1 was down‐regulated to constitution abundance to balance the growth of the resistant NIL Pi‐4b. In summary, OsBRW1 solicited OsSRFP1 to resist the infection of blast fungus in rice by inducing the synergism of induced systemic resistance (ISR) and system acquired resistance (SAR) and to balance the growth of rice plants. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION The content of 2‐acetyl‐1‐pyrroline (2‐AP) directly affects the aroma and taste of rice. Δ1‐Pyrroline and methylglyoxal are the precursors of 2‐AP synthesis, and β‐glucosidase plays an important role in the synthesis of methylglyoxal. In this study, β‐glucosidase gene cloned from Pyrococcus furiosus was molecularly modified to obtain the high‐temperature‐resistant β‐glucosidase gene 371‐β‐glucosidase (T371A), which was transformed into kitaake varieties (Oryza sativa L. subsp. japonica) by Agrobacterium‐mediated transformation method, and transgenic rice with heterologous expression of T371A was obtained. Experiments were conducted in transgenic rice to investigate whether this gene had an effect on the synthesis of 2‐AP.Under the optimum reaction temperature of 50°C and cooking temperature of 100°C, the enzyme activity of β‐glucosidase in transgenic rice seeds was prominently increased by 260–280% and 419–426% over that of the control, respectively. The content of 2‐AP in transgenic rice seeds significantly increased by 75–105% under normal temperature and high‐temperature cooking conditions compared with the control. It was also found that transgenic rice increased the content of methylglyoxal and decreased the expression of betaine aldehyde dehydrogenase (BADH2).The high‐temperature‐tolerant β‐glucosidase gene obtained in this study provides an innovative technical strategy for molecular breeding of high‐edible aroma crops and has wide application potential. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa) provides >20% of the consumed calories in the human diet. However, rice is also a leading source of dietary cadmium (Cd) that seriously threatens human health. Deciphering the genetic network that underlies the grain-Cd accumulation will benefit the development of low-Cd rice and mitigate the effects of Cd accumulation in the rice grain. In this study, we identified a QTL gene, OsCS1 , which is allelic to OsMTP11 and encodes a protein sequestering Cd in the leaf during vegetative growth and preventing Cd from being translocated to the grain after heading in rice. OsCS1 is predominantly expressed in leaf vascular parenchyma cells, where it binds to a vacuole-sorting receptor protein OsVSR2 and is translocated intracellularly from the trans -Golgi network to pre-vacuolar compartments and then to the vacuole. In this trafficking process, OsCS1 actively transports Cd into the endomembrane system and sequesters it in the vacuoles. There are natural variations in the promoter of OsCS1 between the indica and japonica rice subspecies. Duplication of a G-box-like motif in the promoter region of the superior allele of OsCS1 from indica rice enhances the binding of the transcription factor OsIRO2 to the OsCS1 promoter, thereby promoting OsCS1 expression. Introgression of this allele into commercial rice varieties could significantly lower grain-Cd levels compared to the inferior allele present in japonica rice. Collectively, our findings offer new insights into the genetic control of leaf-to-grain Cd translocation and provide a novel gene and its superior allele for the genetic improvement of low-Cd variety in rice. A QTL gene, Cadmium Safe 1 (CS1) that is allelic to OsMTP11, was cloned and functionally characterized in this study. OsMTP11 sequesters Cd into the vacuoles via the endomembrane system of phloem parenchyma cells in the leaves and prevents it from being translocated to rice grains. This study provides new insights into the genetic control of Cd translocation from the leaves to rice grains and will facilitate low-Cd rice breeding. [ABSTRACT FROM AUTHOR]