Rice最新文献

Melatonin (Mel), a multifunctional molecule, has emerged as a pivotal regulator of plant stress responses, enhancing antioxidant defenses, and modulating metabolic pathways. This meta-analysis evaluated the role of Mel in mitigating various abiotic stresses, including salinity, drought, heavy metals, light intensity, and humidity, across diverse experimental conditions in rice crop. The findings reveal significant improvements in enzymatic antioxidant activities such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX), with notable increases in POD (77%) and CAT (61%) activities under hydroponic application. Mel application reduced oxidative stress markers, such as hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), by up to 45% and 54%, respectively, highlighting its capacity to alleviate cellular damage under stress conditions. Additionally, Mel enhanced osmotic regulator such as proline, soluble sugar, and protein accumulation, contributing to osmotic adjustment, with an exceptional increase of 987% proline contents in Thailand. Experimental type and application methods significantly influenced the efficacy of Mel. Hydroponic treatments and seed soaking methods consistently showed the highest improvement in stress tolerance, while field experiments exhibited variability. The effects were also modulated by light intensity and humidity. Under light intensity of 150 µmol m⁻² s⁻¹, Mel enhanced antioxidant activities and reduced oxidative damage, while humidity at 70-75% showed the highest stress alleviation effects. These findings highlight Mel's complex contribution to increasing plant resilience by control of antioxidant enzymes, reduction of oxidative damage, and enhancement of osmotic adaptations under abiotic pressures. The present study offers a thorough knowledge of Mel's potential as a plant growth regulator, therefore guiding sustainable development under demanding environmental conditions.

This study presents a detailed analysis of the molecular mechanisms involved in heat stress tolerance in rice, focusing on the endoplasmic reticulum (ER) protein processing pathway. Through RNA sequencing (RNA-seq), we identified differentially expressed genes in two rice varieties, BNP162 and BNP206, emphasizing the importance of ER quality control mechanisms in maintaining cellular balance during heat stress. We identified three novel genes, Os11g0244200, Os01g0135800, and Os04g0445100, belonging to the Hsp20/alpha crystallin family, which are upregulated in response to heat stress. These genes play essential roles in protein stabilization, folding, and preventing aggregation, critical functions for maintaining protein balance under stress conditions. The upregulation of these genes highlights their potential in enhancing thermotolerance, a key trait for rice cultivation in the face of global climate change challenges. Our findings suggest that these novel genes could be promising targets for genetic manipulation to enhance heat tolerance in rice, contributing to the development of heat-resistant rice varieties. This research provides new insights into the molecular mechanisms of heat stress adaptation and lays a solid foundation for future studies aimed at improving crop resilience to environmental stress.

Biopesticides are promising alternatives to chemical pesticides because of their low residual effects, high selectivity, and capacity for long-term disease control. Melatonin (N-acetyl-5-methoxytryptamine) may be an ideal candidate for biopesticide because it is widely present in the plant kingdom, involved in growth, development, and stress-induced responses in plants, and can inhibit the growth and propagation of some microbial pathogens. However, it remains largely unclear whether melatonin influences rice and the blast fungus Magnaporthe oryzae. Here, we demonstrate that melatonin enhances rice immunity and inhibits the growth of M. oryzae, resulting in resistance to rice blast disease. Melatonin acts in rice response to M. oryzae because biosynthesis-related genes are induced upon M. oryzae infection. Melatonin treatment remarkably reduces blast disease severity in a susceptible rice accession. Mechanistically, melatonin treatment activates the mitogen-activated protein kinase cascades and up-regulates the expression of defense-related genes. Melatonin treatment also significantly inhibits the growth, sporulation, and spore germination of M. oryzae. Notably, melatonin treatment results in the death of M. oryzae hyphal cells. Altogether, our findings indicate that melatonin plays dual roles in the rice-M. oryzae interactions, activating rice immunity and inhibiting fungal growth. Thus, this study offers insights into the potential development of novel melatonin-based biopesticides for controlling rice blast disease.

Calcineurin B-like interacting protein kinases (CIPKs) are central regulators of plant development and stress adaptation. However, the specific roles of individual CIPK family members remain largely unexplored in major crops like wheat and rice. In this study, we characterized the function of TaCIPK19-3D through overexpression in transgenic rice and CRISPR-Cas9-mediated oscipk19 knockout lines. Expression profiling and subcellular localization analyses revealed that TaCIPK19-3D is associated with chloroplast development and metabolic activity. Overexpression lines exhibited enhanced chloroplast structure, increased chlorophyll biosynthesis, stomatal conductance, net photosynthetic rate, transpiration, and elevated levels of K⁺/Na⁺, Ca²⁺, and Mg²⁺, resulting in improved growth and yield compared to wild-type and mutant lines. Notably, TaCIPK19-3D overexpression conferred increased salt tolerance by upregulating ABA signaling, antioxidant responses, and proline biosynthesis. Key genes involved in chlorophyll synthesis (OsCAO, OsCHLH) and salt stress responses (OsAPX2, OsP5CS, OsABA2) were significantly upregulated in transgenic plants. Protein interaction studies using yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays demonstrated that TaCIPK19-3D interacts with TaFBA-4D and four CBL proteins (TaCBL1, TaCBL3, TaCBL4, and TaCBL7). Collectively, our findings reveal that TaCIPK19-3D positively regulates photosynthesis, ion homeostasis, and stress-responsive signaling pathways, highlighting its potential for improving crop productivity and stress resilience in wheat and rice.

Polyploidy plays a crucial role in plant evolution, as polyploid plants possess larger genomes compared to their diploid counterparts. This genomic expansion leads to changes in gene redundancy and interactions, which alter the physiological metabolism of polyploids. Carbohydrate metabolism is a crucial energy metabolism pathway in plants, significantly impacting plant growth and development. In this study, we employed multi-omics analysis to investigate the differences in carbohydrate metabolism between diploid and tetraploid flag leaves during both day and night periods at the grain-filling stage. Our results revealed significant differences in carbohydrate metabolism between diploid (GFD-2X) and autopolyploid (GFD-4X) rice during both day and night periods. Chromosome doubling resulted in GFD-4X exhibiting reduced sucrose catabolism during the daytime, while starch synthesis and catabolism were stronger in GFD-4X compared to GFD-2X during both daytime and nighttime. Additionally, the phosphorylation of monosaccharides was enhanced in GFD-4X, suggesting that changes in chromosome ploidy altered carbohydrate metabolism, thereby benefiting the regulation and redistribution of carbohydrates in tetraploid rice. Furthermore, analysis of respiration-related pathways indicated that tetraploid rice may have more vigorous respiratory activity. Specifically, GFD-4X exhibited enhanced glycolysis and TCA cycle activity at night, resulting in more efficient energy production, which in turn influenced growth and the developmental process. This study examined the regulatory networks of genes, proteins, and metabolites involved in carbohydrate metabolism in diploid and tetraploid rice during both day and night periods. Our findings offer insights into how chromosome ploidy affects carbohydrate metabolism and reveal the distinct growth and developmental mechanisms of tetraploid rice.

Rice cultivation involves the large amounts of fertilizers application, but nitrogen (N) use efficiency remains low. Endophytes are considered key microorganisms that regulate nitrogen utilization and gaseous nitrogen loss in rice paddy ecosystems. However, systematic studies on the effectiveness and underlying mechanisms of endophytes in nitrogen utilization by crops within paddy fields are still scarce. This study employed microcosmic experiments to investigate the effects of endophytes on gaseous nitrogen loss from paddy soil and inorganic nitrogen utilization in rice plants. Results demonstrated that colonization of endophytes increased the efficiency of inorganic N use by approximately twofold. The simultaneous addition of rice roots colonized with endophytes to the soil resulted in a significant increase in ammonium (NH₄⁺) concentrations by 121-138% as well. Notably, colonization with endophytes reduced cumulative nitrous oxide (N₂O) emissions by 13-21% compared to the control. Importantly, the endophytes were shown to enhance soil redox capacity by increasing Clostridium abundance and Fe²⁺ concentration, thereby promoting the dissimilatory nitrate reduction to ammonium (DNRA) and mitigating soil N loss. These findings underline the potential of rice endophytes in paddy field management to enhance soil nitrogen retention and reduce nitrogen loss.

Plants defend themselves against pathogens through pattern-triggered immunity (PTI) and effector-triggered immunity (ETI), with the latter often inducing a hypersensitive response (HR) characterized by localized programmed cell death (PCD). Lesion mimic mutants (LMMs), which spontaneously form HR-like lesions in the absence of pathogen infection, have served as valuable genetic resources for dissecting the molecular mechanisms underlying cell death and immune signaling in plants. In this study, we characterize the rice lesion mimic mutant spl17, derived from the IR64 cultivar, and identify the mutation responsible for its phenotype. We demonstrate that the spl17 mutation leads to the accumulation of reactive oxygen species (ROS), induces light-dependent cell death and lesion formation, elevates levels of salicylic acid (SA) and jasmonic acid (JA), activates defense-related genes, and confers enhanced resistance to Xanthomonas oryzae pv. oryzae. Using map-based cloning, we identified a single Histidine-25-Arginine substitution (OsCAD1^H25R) in OsCAD1, a gene encoding a membrane attack complex/perforin (MACPF) domain-containing protein in rice, as the causal mutation. CRISPR/Cas9 genome editing revealed that a knockout of OsCAD1 (OsCAD1^KO) results in seedling lethality, whereas a weak allele (OsCAD1^D8) leads to a viable lesion mimic phenotype and enhances resistance to X. oryzae pv. oryzae. Subcellular localization studies demonstrated that eGFP-OsCAD1 is broadly distributed in Nicotiana benthamiana cells. Transcriptome analyses, including RNA-Seq and Gene Set Enrichment Analysis (GSEA), indicate that differentially expressed genes (DEGs) in spl17 are enriched in catalytic activity, metabolic processes, and membrane functions. Together, these results suggest that OsCAD1 is indispensable for rice growth and development, and that its mutation triggers cell death and defense responses.

Wheat (Triticum aestivum) is a globally important staple crop that faces increasing challenges from climate change, particularly the combined effects of heat and drought stress. The BTB (Broad Complex, Tramtrack, and Bric-à-Brac) gene family is involved in diverse biological processes, including stress responses, but its characterization in T. aestivum remains limited. This study aimed to comprehensively investigate the BTB gene family in T. aestivum and identify key genes potentially involved in resilience to abiotic stress.In the current study, we identified 62 BTB genes in T. aestivum using BLAST and Hidden Markov Model (HMM) approaches. Phylogenetic analysis classified these genes into nine subgroups based on conserved domain architecture. Gene structure analysis revealed diverse exon-intron organizations, supporting evolutionary divergence among subgroups. Chromosomal mapping demonstrated an uneven distribution of BTB genes across the A, B, and D sub-genomes, with the highest number localized on sub-genome D. Cis-regulatory element analysis highlighted the presence of multiple stress-responsive motifs, particularly those associated with heat and drought responses, i.e., ABRE, G-box, CAAT-box, TATA-box. Expression profiling using transcriptome data from two T. aestivum varieties (Atay 85 and Zubkov) revealed differential regulation of BTB gene family members under drought, heat, and combined stress conditions. Furthermore, qRT-PCR validation showed that TaBTB11, TaBTB56, TaBTB57, and TaBTB58 were consistently regulated across all three stress conditions, highlighting their potential as key targets for stress-resilient T. aestivum breeding. Furthermore, Green fluorescent protein (GFP) localization confirmed that these genes were expressed in the nucleus.This study highlights key genes, i.e., TaBTB11, TaBTB56, TaBTB57, and TaBTB58, as potential targets for marker-assisted selection and genetic improvement of T. aestivum for enhanced resilience to combined heat and drought stress.

Rice production is gravely threatened by bacterial leaf streak (BLS). BLS prevention and control rely heavily on chemical pesticides, which contaminate the environment and endanger human health. Here, we evaluated the effects of inducer of plant resistance ZhiNengCong (ZNC), which is derived from endophytic fungi Paecilomyces variotii, the chemical pesticide dioctyl diethylenetriamine (DDL) and the antibiotic pesticide zhongshengmycin (ZSM) on grain size and quality of diseased- rice (DR). BLS significantly reduced the thousand-grain weight and seed setting rate of rice plants, which could be restored by ZNC rather than DDL or ZSM. Transcriptome and metabolomics profiling showed that ZNC increased the expression levels of resistance-, growth- and sugars, amino acids and lipid metabolism-related genes in DR leaves and restored the levels of carbohydrates, vitamins, nucleotides and amino acids in DR grains, which is better than DDL and ZSM. This study demonstrates that plant immune inducers are more effective than conventional pesticides in restoring DR yield and quality, which provides novel insights into the innovation of green biopesticides in sustainable crop production.

Salt stress is a major limiting factor for rice productivity worldwide, and improving salt tolerance is crucial for ensuring sustainable agricultural production. In this study, we investigate the use of RNA aptamers to modulate eukaryotic initiation factor 4 A (eIF4A), a key regulator of translation initiation under stress conditions, to enhance salt stress tolerance in rice (Oryza sativa). Using Systematic Evolution of Ligands by EXponential enrichment (SELEX), we isolated high-affinity RNA aptamers that specifically bind to eIF4A. One aptamer, eApt-2, was found to bind eIF4A with high affinity, selectively blocking cap-dependent translation initiation. Radioisotope‑based helicase assays confirmed that eApt‑2 does not impair eIF4A's intrinsic RNA‑unwinding activity. Transfected rice expressing eApt-2 exhibited enhanced salt stress tolerance, with improved growth, biomass accumulation, and photosynthetic activity under saline conditions. Moreover, stable transgenic rice lines expressing eApt‑2 maintained enhanced growth and biomass accumulation under 150 mM NaCl stress, mirroring transient expression results, and transgenic Arabidopsis lines showed similar tolerance. Our results demonstrate the potential of RNA aptamers as a precise, reversible tool for enhancing stress resilience in crops, offering an alternative to conventional genetic modification methods. This study opens new avenues for engineering salt-tolerant rice and highlights the broader applicability of RNA aptamers in improving plant responses to abiotic stresses.