Forthcoming Articles http://www.ricesci.org EN-US http://www.ricesci.org/EN/1672-6308/current.shtml http://www.ricesci.org 1672-6308 http://www.ricesci.org/EN/abstract/abstract10159.shtml http://www.ricesci.org/EN/abstract/abstract10158.shtml Striga constitutes a major limitation to cereal crop production, and identifying cultivars that avoid or reduce the germination of the parasites鈥� seeds is crucial. This study evaluated a diverse collection of 31 rice cultivars for Striga resistance and the role of cytochrome P450 genes in resistance or susceptibility. The phenotype of the resistant was characterized by the ability of the variety to support no or few emerging Striga. The presence or absence of the cytochrome P450 gene was determined by Multiplex PCR analysis. Upon examination, it became clear that five cultivars showed good resistance to Striga, while twenty exhibited intermediate resistance and six were very susceptible. In contrast, the resistant genotypes had few or no emerged Striga. Striga emerged early and rapidly in susceptible genotypes, supporting a higher number of emerged and attached Striga and Striga dry weight per plant. Multiplexed PCR analysis showed that 87.1% of the cultivars possessed the 93-11/Bala alleles, and 12.9% had the Nipponbare/Azucena alleles for strigolactone biosynthesis. Evaluating the variability of the 3 000 rice genomic data in these genes revealed similar results. The outcome of this research identified genotypes that are resistant, tolerant, and susceptible. This finding may be useful in breeding program for Striga resistance. The next steps for this research could involve testing the resistant genotypes in the field or using them as a starting point for a genetic experiment.]]> http://www.ricesci.org/EN/abstract/abstract10157.shtml http://www.ricesci.org/EN/abstract/abstract10156.shtml http://www.ricesci.org/EN/abstract/abstract10155.shtml http://www.ricesci.org/EN/abstract/abstract10154.shtml Phosphorus (P) levels alters the allelopathic activity of rice seedlings against lettuce seeds. Here, we investigated the effect of P deficiency on allelopathic potential in non-pigmented and pigmented rice varieties. Rice seedlings of the white variety Khao Dawk Mali (KDML105, non-pigmented) and the black varieties Jao Hom Nin (JHN, pigmented) and Riceberry (RB, pigmented) were grown in high P (HP) and low P (LP) conditions. Morphological and metabolic responses to P deficiency were investigated. P deficiency inhibited shoot growth but promoted root growth of rice seedlings in all three varieties. Moreover, P deficiency led to decreased cytosolic phosphate (Pi) and total P in shoot and root tissues. The subsequent reduction of internal P enhanced the accumulation of phenolic contents in both shoot and root tissues of the seedlings. Subsequently, allelopathy-based inter- and intraspecific interactions were validated by using water extracts from seedlings of the three varieties grown under HP and LP conditions. The extracts were tested on seeds of lettuce, the weed Dactyloctenium aegyptium, and the same rice variety. Shoot and root extracts of P-deficient seedlings reduced the germination of all the receiver plants. The shoot extract of P-deficient KDML105 seedlings reduced the germination index of lettuce seeds to 1%, while the shoot extracts of P-deficient RB and JHN seedlings produced GIs of 32% and 42%, respectively. However, when rice seeds were exposed to their own LP shoot and root extracts, their germination indices were enhanced up to 4-fold, compared with the HP extracts. Shoot extracts of P-deficient plants also promoted the germination of D. aegyptium by about 2鈥�3-fold whereas root extracts of P-deficient plants did not. Therefore, P starvation led to the accumulation and exudation of phenolics in the shoots and roots of rice seedlings, which then changed their allelopathic activities. To thrive under P deficiency, rice seedlings potentially release signaling chemicals to suppress different species nearby and simultaneously promote their own germination and growth.

]]> http://www.ricesci.org/EN/abstract/abstract10142.shtml Reasonable nitrogen (N) application is a promising strategy for reducing crop cadmium (Cd) toxicity. However, which state of N and how much N affects Cd tolerance and accumulation in rice remains unclear. This study explored the influence of different N-fertilizer forms (NH₄NO_3, NH₄Cl, and KNO₃) and dosages on Cd tolerance and absorption in Cd-stressed N-sensitive and insensitive indica accessions. The results indicated that the Cd tolerance of N-sensitive indica accessions is more robust than N-insensitive indica accessions. Furthermore, the shoot Cd contents and Cd translocation rates of both N-sensitive and insensitive indica accessions were decreased with an appropriate supply of NH₄NO₃ and NH₄⁺, whereas comparable or slightly improved with increased NO₃^-. Unfortunately, we did not find significant and regular differences in Cd accumulation or translocation between N-sensitive and N-insensitive rice accessions. Consistent with the reduction of shoot Cd content, adding NH₄NO₃ and NH₄⁺ also inhibited the instantaneous root Cd²⁺ uptake. The expression changes of Cd transport-related genes under different N forms and dosages suggested that the decreased shoot Cd content, caused by increased NH₄NO₃ and NH₄⁺, is likely achieved by reducing the transcription of OsNRAMP1 and OsIRT1. In summary, our findings reveal that the appropriate supply of NH₄NO₃ and NH₄⁺ could reduce Cd uptake and transport in rice seedlings and suggest that rational N management could reduce Cd risk in rice production.

]]> http://www.ricesci.org/EN/abstract/abstract10141.shtml indica rice cultivar ZhongHui 8015 (ZH8015) using PacBio HiFi, Hi-C, and ONT (Oxford Nanopore Technologies) ultra-long sequencing technologies, annotating 43 037 gene structures. Subsequently, utilizing this genome along with transcriptomic and metabolomic techniques, we explored the response of ZH8015 to brown planthopper (BPH) infestation. Continuous transcriptomic sampling indicated significant changes in gene expression levels around 48 h after BPH feeding. Enrichment analysis revealed particularly significant alterations in genes related to reactive oxygen species scavenging and cell wall formation. Metabolomic results demonstrated marked increases in levels of several monosaccharides as cell wall components and dramatic changes in flavonoid contents. Omics association analysis identified differentially expressed genes associated with key metabolites, shedding light on ZH8015鈥檚 response to BPH infestation. In summary, our study constructed a reliable genome sequence resource for ZH8015, and the preliminary multi-omics results will guide future insect-resistant breeding research.]]> http://www.ricesci.org/EN/abstract/abstract10140.shtml Oryza sativa var. glutinosa) is one of the most popular varieties among thousands of different rice varieties available worldwide. There is a growing interest in glutinous rice due to its abundant nutritional composition and health benefits. This review aims to summarize the nutritional compositions, volatile compounds, and health benefits of glutinous rice. Further in-depth studies are needed to explore the utilization of glutinous rice in enhancing the applications of processing technologies and the development of new food products. Glutinous rice has been proven to have numerous health benefits including antioxidant activity, bioactive compounds, anti-cancer, anti-inflammatory, anti-diabetic, and cholesterol-lowering effects. In addition to nutritional compositions, major key volatile compounds have been identified in glutinous rice which could serve as a functional food for human consumption. The emerging processing technologies related to glutinous rice are elaborated to improve the latest development for incorporating it into various food products.]]> http://www.ricesci.org/EN/abstract/abstract10139.shtml The yield potential of rice is seriously affected by heat stress due to climate change. Since rice is a staple food globally, it is imperative to develop heat-resistant rice varieties. Thus, a thorough understanding of the underlying complex molecular mechanisms governing heat tolerance and the impact of high temperatures on various critical stages of the crop is needed. Adoption of conventional and innovative breeding strategies offers a long-term advantage over other methods, such as agronomic practices, to counter heat stress. In this review, we summarize the effects of heat stress, regulatory pathways for heat tolerance, phenotyping strategies, and various breeding methods available for developing heat-tolerant rice. We offer perspectives and knowledge to guide future research endeavors for enhancing rice鈥檚 ability to withstand heat stress and ultimately benefit humanity.

]]> http://www.ricesci.org/EN/abstract/abstract10138.shtml In Africa, the genera Diopsis, Maliarpha and Chilo are the most important pests affecting rice productivity, while in Asia the most important are Nilaparvata, Scirpophaga, Sogatella, Chilo, Cnaphalocrocis, Sesamia, and Nephotettix genera, demonstrating different pests under a continent overview. Regarding diseases, in Africa, the fungi Pyricularia, the bacteria Xanthomonas and the virus Sobemovirus are the most significant. In Asia, the fungal genera Fusarium, Pyricularia, Rhizoctonia, Bipolaris, Curvularia, Ustilaginoidea, Alternaria, and Sarocladium, and bacteria Xanthomonas, Pantoea, Pseudomonas, and Burkholderia are the most frequently reported. These findings reveal distinct geographic patterns in the distribution of rice pests and diseases, implying the development of specific regional management guidelines. In terms of yield loss, the most severe fungi are Pyricularia and Bipolaris, responsible for blast and brown spot diseases, respectively. Both occur in Africa and Asia and affect different parts of the plant, with Bipolaris being more evident on the leaves. A big concern restricted to Africa is the Sobemovirus (causing rice yellow mottle virus), which can lead to yield losses of up to 100%, primarily affecting the leaves. This study significantly contributes to identifying global rice pests and diseases, assessing their current distribution patterns and evaluating their effects on future rice productivity. Furthermore, it highlights the overlooked reporting of studies in Africa, despite the region鈥檚 significance in rice cultivation and production.]]> http://www.ricesci.org/EN/abstract/abstract10136.shtml http://www.ricesci.org/EN/abstract/abstract10135.shtml The basic region/leucine zipper (bZIP) transcription factors play important roles in plant development and responses to abiotic and biotic stresses. OsbZIP53 has been reported to regulate resistance to Magnaporthe oryzae in rice by analyzing APIP5-RNAi transgenic plants. To further investigate the biological functions of OsbZIP53, we generated osbzip53 mutants using CRISPR-Cas9 editing and OsbZIP53 over-expression transgenic plants. Comprehensive analysis of phenotypical, physiological, and transcriptional data showed that knocking-out OsbZIP53 not only improved disease resistance by inducing a hypersensitivity response in plants, but also regulated the immune response through the salicylic acid pathway. Specifically, disrupting OsbZIP53 increased H₂O₂ accumulation by promoting reactive oxygen species generation through up-regulation of several respiratory burst oxidase homologs (Osrboh genes) and weakened H₂O₂ degradation by directly targeting OsMYBS1. In addition, the growth of osbzip53 mutants was seriously impaired, while OsbZIP53 over-expression lines displayed a similar phenotype to the wild type, suggesting that OsbZIP53 has a balancing effect on rice immune response and growth.

]]> http://www.ricesci.org/EN/abstract/abstract10134.shtml OsGOLDEN-LIKE1 (OsGLK1) mRNA in the tapetum of rice (Oryza sativa) anthers. However, the mechanism by which OsCPPR1 recognizes and binds to OsGLK1 transcripts remains unknown. Through protein structure prediction and macromolecular docking experiments, we observed that distinct PPR motif structures of OsCPPR1 exhibited varying binding efficiencies to OsGLK1 RNA. Moreover, our RNA-EMSA experiment demonstrated that the recombinant CPPR1 can directly recognize and bind to OsGLK1 mRNA in vitro through the RNA-EMSA experiment. This further confirmed that the mutations in the conserved amino acids in each PPR motif resulted in loss of activity, while truncation of OsCPPR1 decreased its binding efficiency. These findings collectively suggest that it may require some cofactor to assist in cleavage, a facet that warrants further exploration in subsequent studies.]]> http://www.ricesci.org/EN/abstract/abstract10133.shtml Ustilaginoidea virens, has emerged as a significant global threat to rice production. The mechanism of carbon catabolite repression plays a crucial role in the efficient utilization of carbon nutrients and enzyme regulation in the presence of complex nutritional conditions. Although significant progress has been made in understanding carbon catabolite repression in fungi such as Aspergillus nidulans and Magnaporthe oryzae, its role in U. virens remains unclear. To address this knowledge gap, we identified UvCreA, a pivotal component of carbon catabolite repression, in U. virens. Our investigation revealed that UvCreA localizes to the nucleus. Deletion of UvCreA resulted in decreased growth and pathogenicity in U. virens. Through RNA-seq analysis, it was found that the knockout of UvCreA led to the up-regulation of 514 genes and down-regulation of 640 genes. Moreover, UvCreA was found to be involved in the transcriptional regulation of pathogenic genes and genes associated with carbon metabolism in U. virens. In summary, our findings indicated that UvCreA is important in fungal development, virulence, and the utilization of carbon sources through transcriptional regulation, thus making it a critical element of carbon catabolite repression.]]> http://www.ricesci.org/EN/abstract/abstract10132.shtml SD1 (encoding GA20ox2), has been widely applied to improve yield in rice breeding. However, research on its transcriptional regulation is limited. Here, we identified a transcription factor OsbZIP01 which can suppress the expression of SD1 and regulate gibberellin (GA) biosynthesis in rice. Knockout mutants of OsbZIP01 exhibited increased plant height, while the overexpression lines showed a semi-dwarf phenotype and diminished germination rate. Furthermore, the semi-dwarf phenotype of OE-bZIP01 was caused by the reduced internode length, which was accompanied by a thin stem width. OsbZIP01 was mainly expressed in shoots, especially in leaves and sheaths. OsbZIP01 protein was localized in the nucleus and showed transcriptional repression activity. In addition, OsbZIP01 could directly bind to the promoter of the OsSD1 gene, and inhibit its transcription. The semi-dwarf phenotype of OsbZIP01 overexpression plants could be rescued by exogenous GA₃. Meanwhile, the sd1 bzip01 double mutant showed a shorter shoot length compared with the wild-type, indicating that OsbZIP01 regulates plant growth mainly through the GA biosynthesis pathway. Collectively, OsbZIP01 negatively regulates GA biosynthesis by restraining SD1 transcription, thereby affecting plant growth and development]]> http://www.ricesci.org/EN/abstract/abstract10131.shtml http://www.ricesci.org/EN/abstract/abstract10130.shtml http://www.ricesci.org/EN/abstract/abstract10129.shtml http://www.ricesci.org/EN/abstract/abstract10128.shtml Ustilaginoidea virens is a common rice pathogen that can easily lead to a decline in rice quality and the production of toxins, posing potential risks to human health. In this review, we conduct a comprehensive literature review of research since the discovery of rice false smut. We provide a comprehensive and, at times, critical overview of the main results and findings from related research, and propose future research directions. Firstly, we delve into the interaction between U. virens and rice, including the regulation of transcription factors, the process of U. virens infecting rice panicles, and the plant immune response caused by rice infection. Following that, we discuss the identification and characterization of mycotoxins produced by the pathogenic fungus, as well as and strategies for disease management. We emphasize the importance of comprehensive agricultural prevention and control methods for the sustainable management of U. virens. This knowledge will update our understanding of the interaction between U. virens and rice plants, offering a valuable perspective for those interested in U. virens.

]]> http://www.ricesci.org/EN/abstract/abstract10127.shtml Anthropogenic methane emissions are a leading cause of the increase in global average temperatures, often referred to as global warming. Flooded soils play a significant role in methane production, where the anaerobic conditions promote the production of methane by methanogenic microorganisms. Rice fields contribute a considerable portion of agricultural methane emissions, as rice plants provide both factors that enhance and limit methane production. Rice plants harbor both methane- producing and methane-oxidizing microorganisms. Exudates from rice roots provide source for methane production. while oxygen delivered from the root aerenchyma enhances methane oxidation. Studies have shown that the diversity of these microorganisms depends on rice cultivars with some genes characterized as harboring specific groups of microorganisms related to methane emissions. However, there is still a need for research to determine the balance between methane production and oxidation, as rice plants possess the ability to regulate net methane production. Various agronomical practices, such as fertilizer and water management, have been employed to mitigate methane emissions. Nevertheless, studies correlating agronomic and chemical management of methane with productivity are limited. Moreover, evidences for breeding low methane-emitting rice varieties are scattered largely due to the absence of coordinated breeding programs. Research has indicated that phenotypic characteristics, such as root biomass, shoot architecture, and aerenchyma, are highly correlated with methane emissions. This review discusses available studies that involve the correlation between plant characteristics and methane emissions. It emphasizes the necessity and importance of breeding low methane-emitting rice varieties in addition to existing agronomic, biological, and chemical practices. The review also delves into the ideal phenotypic and physiological characteristics of low methane-emitting rice and potential breeding techniques, drawing from studies conducted with diverse cultivars, mutants, and transgenic plants.

]]> http://www.ricesci.org/EN/abstract/abstract10112.shtml The aroma of fragrant rice is one of the grain quality attributes that significantly influence consumer preferences and prices in world markets. The volatile compound 2-acetyl-1-pyrroline (2AP) is recognized as a key component of the aroma in fragrant rice. The variation in grain 2AP content among fragrant rice varieties is associated with the expression of the badh2 gene, with 19 alleles having been identified. The grain 2AP content is strongly influenced by environmental and management factors during cultivation as well as post-harvest conditioning. This review identified the major abiotic and biotic factors that control grain 2AP content. Abiotic factors, such as water, temperature, light quality, fertilizer application (both macro- and micro-nutrients), and soil properties, including salinity, contribute to the aroma of fragrant rice. The grain 2AP content is also affected by biotic factors, including microorganisms that produce aromatic compounds, thus influencing the grain aroma in fragrant rice. Post-harvest management, including storage and drying conditions, can significantly impact the grain 2AP content, and proper post-harvest conditions can enhance the intensity of the grain aroma. This review suggests that there are rice varieties that serve as potential sources of genetic material for breeding rice varieties with high grain aroma content. However, the trait is strongly influenced by both abiotic and biotic factors, as well as post-harvest management. This review provides a summary of recent research on the major factors affecting aroma content in fragrant rice. This knowledge will facilitate further research on the production of high-quality rice to meet the demands of farmers and consumers.

]]> http://www.ricesci.org/EN/abstract/abstract10111.shtml http://www.ricesci.org/EN/abstract/abstract10110.shtml Rice (Oryza sativa L.) is the most important food crop consumed by the developing world. Whereas the total production and yield stability is largely affected by the environmental stresses. Drought stress affects about 45% of the world鈥檚 rice area. Drought stress has been drawn a great attention in the past half century due to its frequently occurrence and costly impacts. Drought stress affects plant at molecular, biochemical, physiological and phenotypic levels. Conventional breeding method of singly pedigree selection was commonly used to breed a numbers of drought-tolerant rice varieties since Green Revolution. As plant molecular biology progresses rapidly, hundreds of drought tolerant QTLs/genes were discovered and tested in rice crop under both indoor and field condition. A number of drought tolerant rice varieties were developed through mark-assisted selection and genetically engineered approaches. Several genes were introgressed into elite germplasm to develop commercially accepted drought tolerant varieties. This review provids up-to-dated information on proof-of-concept genes and breeding methods in molecular breeding eras, which could be used for rice breeders to develop drought-tolerant rice variety.

]]> http://www.ricesci.org/EN/abstract/abstract10109.shtml http://www.ricesci.org/EN/abstract/abstract10108.shtml Oryza sativa L.) leaves is closely related to plant architecture, physiological activities, and resistance. However, it is unclear whether there is a co-regulatory relationship between the morphological development of leaves and adaptation to a drought environment. In this study, a drought-sensitive, roll-enhanced, and narrow-leaf mutant (renl1) was induced by an ethyl methane sulfonate (EMS) solution from a semi-rolled leaf mutant (srl1), which was obtained from Nipponbare (NPB) through an EMS solution. Map-based cloning and functional validation showed that RENL1 encoded a cellulose synthase, with an allele of NRL1/OsCLSD4. The RENL1 mutation resulted in reductions of vascular bundles, vesicular cells, cellulose, and hemicellulose contents in cell walls, diminishing the water-holding capacity of leaves. In addition, the root system of renl1 was poorly developed and its ability to scavenge reactive oxygen species (ROS) was decreased, leading to an increase of reactive oxygen species after drought stress. Meanwhile, genetic results showed that RENL1 and SRL1 synergistically regulated cell wall components. Our results revealed a theoretical basis for further improving the molecular regulation mechanism of cellulose on rice drought tolerance, and provided a new genetic resource for enhancing the synergistic regulation network of plant type and stress resistance, thereby realizing simultaneous improvement of multiple traits in rice. ]]> http://www.ricesci.org/EN/abstract/abstract10107.shtml http://www.ricesci.org/EN/abstract/abstract10106.shtml http://www.ricesci.org/EN/abstract/abstract10105.shtml Nostoc flagelliforme is a terrestrial cyanobacterium that can resist many types of stressors, including drought, UV radiation, and extreme temperatures. In this study, we identified the drought tolerance gene NfcrtO, which encodes 尾-carotene ketolase, through screening the transcriptome of N. flagelliforme under water loss stress. Prokaryotic expression of NfcrtO under 0.6 mol/L sorbitol or under 0.3 mol/L NaCl stress significantly increased the growth rate of Escherichia coli solutions. When NfcrtO was heterologously expressed in rice, the seedling height and root length of NfcrtO-overexpressing rice plants were significantly higher than those of the wild type (WT) line grown on 陆-strength Murashige and Skoog solid medium with 120 mmol/L mannitol at the seedling stage. Transcriptome analysis revealed that NfcrtO was involved in osmotic stress, antioxidant, and other stress-related pathways. Additionally, the survival rate of the NfcrtO-overexpression lines was significantly higher than that of the WT line under both hydroponic stress (24% PEG and 100 mmol/L H₂O₂) and soil drought treatment at the seedling stage. Physiological traits, including the activity levels of superoxide dismutase, peroxidase, catalase, total antioxidant capacity, and the contents of proline, trehalose, and soluble sugar, were significantly improved in the NfcrtO overexpression lines relative to those of the WT line under 20% PEG treatment. Furthermore, when water was withheld at the booting stage, the grain yield per plant of NfcrtO- overexpression lines was significantly higher than that of the WT line. Yeast two-hybrid analysis identified interactions between NfcrtO and Dna J protein, E3 ubiquitin-protein ligase, and pyrophosphate-energized vacuolar membrane proton pump. Thus, heterologous expression of NfcrtO in rice could significantly improve the tolerance of rice to osmotic stress, potentially facilitating the development of new rice varieties.]]> http://www.ricesci.org/EN/abstract/abstract10104.shtml http://www.ricesci.org/EN/abstract/abstract10103.shtml http://www.ricesci.org/EN/abstract/abstract10102.shtml http://www.ricesci.org/EN/abstract/abstract10101.shtml 3^鈥� leaching and N₂O emissions, and increasing nitrogen-use efficiency (NUE). Several recent studies have focused on the identification of new BNIs, while little is known about the genetic loci governing their biosynthesis and secretion. We applied a combined transcriptomic and metabolomic analysis to investigate possible biosynthetic pathways and transporters implicated in the biosynthesis and release of BNI 1,9-decanediol (1,9-D), previously identified in rice root exudates. Our results link four fatty acids, icosapentaenoic acid, linoleate, norlinolenic acid, and polyhydroxy-伪,蠅-divarboxylic acid, to 1,9-D biosynthesis, and three transporter families, namely the ATP-binding cassette protein family, the multidrug and toxic compound extrusion family, and the major facilitator superfamily, to 1,9-D release from roots into the soil medium. Our results provide candidates for further work on the genes implicated in the biosynthesis and secretion of 1,9-D and pinpoint genetic loci for crop breeding to improve NUE by enhancing 1,9-D secretion, with the promise of reducing NO₃^鈥� leaching and N₂O emissions from agricultural soils.]]> http://www.ricesci.org/EN/abstract/abstract10099.shtml http://www.ricesci.org/EN/abstract/abstract10094.shtml http://www.ricesci.org/EN/abstract/abstract10086.shtml