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1.
BMC Plant Biol ; 22(1): 233, 2022 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-35525915

RESUMEN

BACKGROUND: Soil salinization is a threat to food security. China is rich in saline land resources for potential and current utilization. The cultivation and promotion of salt-tolerant rice varieties can greatly improve the utilization of this saline land. The super hybrid rice Chaoyouqianhao (CY1000) is one of the most salt-tolerant rice varieties and is widely used, but the molecular mechanism underlying its salt tolerance is not clear. RESULTS: In this study, the characteristics of CY1000 and its parents were evaluated in the field and laboratory. The results showed that aboveground parts of CY1000 were barely influenced by salt stress, while the roots were less affected than those of its parents. A comparative transcriptomic strategy was used to analyze the differences in the response to salt stress among the male and female parents of CY1000 at the seedling stage and the model indica rice 93-11. We found that the salt tolerance of CY1000 was mainly inherited from its male parent R900, and its female parent GX24S showed hardly any salt tolerance. To adapt to salt stress, CY1000 and R900 upregulated the expression of genes associated with soluble component synthesis and cell wall synthesis and other related genes and downregulated the expression of most genes related to growth material acquisition and consumption. In CY1000 and R900, the expression of genes encoding some novel key proteins in the ubiquitination pathway was significantly upregulated. After treatment with MG-132, the salt tolerance of CY1000 and R900 was significantly decreased and was almost the same as that of the wild type after salt stress treatment, indicating that ubiquitination played an important role in the salt tolerance mechanism of CY1000. At the same time, we found that some transcription factors were also involved in the salt stress response, with some transcription factors responding only in hybrid CY1000, suggesting that salt tolerance heterosis might be regulated by transcription factors in rice. CONCLUSION: Our results revealed that the ubiquitination pathway is important for salt tolerance in rice, and several novel candidate genes were identified to reveal a novel salt tolerance regulation network. Additionally, our work will help clarify the mechanism of heterosis in rice. Further exploration of the molecular mechanism underlying the salt tolerance of CY1000 can provide a theoretical basis for breeding new salt-tolerant rice varieties.


Asunto(s)
Oryza , Regulación de la Expresión Génica de las Plantas , Oryza/metabolismo , Fitomejoramiento , Estrés Salino , Factores de Transcripción/genética , Transcriptoma
2.
BMC Genomics ; 23(1): 343, 2022 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-35505282

RESUMEN

BACKGROUND: The sustainable development of rice production is facing severe threats by a variety of pathogens, such as necrotrophic Rhizoctonia solani and hemibiotrophic Xanthomonas oryzae pv. oryzae (Xoo). Mining and applying resistance genes to increase the durable resistance of rice is an effective method that can be used to control these diseases. RESULTS: In this research, we isolated and characterized CYP716A16, which is a positive regulator of rice to R. solani AG1-IA and Xoo, and belongs to the cytochrome P450 (CYP450) protein 716A subfamily. Overexpression (OE) of CYP716A16 resulted in enhanced resistance to R. solani AG1-IA and Xoo, while RNA interference (RNAi) of CYP716A16 resulted in increased susceptibility compared with wild-type (WT) plants. Additionally, jasmonic acid (JA)-dependent defense responses and reactive oxygen species (ROS) were activated in the CYP716A16-OE lines after R. solani AG1-IA inoculation. The comparative transcriptomic and metabolomics analysis of CYP716A16-OE and the WT lines showed that OE of CYP716A16 activated the biosynthesis of flavonoids and increased the amounts of narcissoside, methylophiopogonanone A, oroxin A, and amentoflavone in plants. CONCLUSION: Based on these results, we suggest that JA-dependent response, ROS level, multiple resistance-related proteins, and flavonoid contents play an important role in CYP716A16-regulated R. solani AG1-IA and Xoo resistance. Our results broaden our knowledge regarding the function of a P450 protein 716A subfamily in disease resistance and provide new insight into the molecular mechanism of rice immune response.


Asunto(s)
Oryza , Sistema Enzimático del Citocromo P-450/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Resistencia a la Enfermedad/genética , Oryza/metabolismo , Enfermedades de las Plantas/genética , Especies Reactivas de Oxígeno/metabolismo , Xanthomonas
3.
Int J Mol Sci ; 23(7)2022 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-35409103

RESUMEN

Photoperiod and thermo-sensitive genic male sterile (PTGMS) rice is an important resource for two line hybrid rice production. The SQUAMOSA-promoter binding, such as the (SPL) gene family, encode the plant specific transcription factors that regulate development and defense responses in plants. However, the reports about SPLs participating in male fertility regulation are limited. Here, we identified 19 OsSPL family members and investigated their involvement in the fertility regulation of the PTGMS rice lines, PA2364S and PA2864S, with different fertility transition temperatures. The results demonstrated that OsSPL2, OsSPL4, OsSPL16 and OsSPL17 affect male fertility in response to temperature changes through the MiR156-SPL module. WGCNA (weighted gene co-expression network analysis) revealed that CHI and APX1 were co-expressed with OsSPL17. Targeted metabolite and flavonoid biosynthetic gene expression analysis revealed that OsSPL17 regulates the expression of flavonoid biosynthesis genes CHI, and the up regulation of flavanones (eriodictvol and naringenin) and flavones (apigenin and luteolin) content contributed to plant fertility. Meanwhile, OsSPL17 negatively regulates APX1 to affect APX (ascorbate peroxidase) activity, thereby regulating ROS (reactive oxygen species) content in the tapetum, controlling the PCD (programmed cell death) process and regulating male fertility in rice. Overall, this report highlights the potential role of OsSPL for the regulation of male fertility in rice and provides a new insight for the further understanding of fertility molecular mechanisms in PTGMS rice.


Asunto(s)
Oryza , Fertilidad/genética , Flavonoides/metabolismo , Regulación de la Expresión Génica de las Plantas , Oryza/metabolismo , Fotoperiodo , Temperatura
4.
Int J Mol Sci ; 23(7)2022 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-35409186

RESUMEN

Catalases (CATs) are important self-originating enzymes and are involved in many of the biological functions of plants. Multiple forms of CATs suggest their versatile role in lesion mimic mutants (LMMs), H2O2 homeostasis and abiotic and biotic stress tolerance. In the current study, we identified a large lesion mimic mutant9428 (llm9428) from Ethyl-methane-sulfonate (EMS) mutagenized population. The llm9428 showed a typical phenotype of LMMs including decreased agronomic yield traits. The histochemical assays showed decreased cell viability and increased reactive oxygen species (ROS) in the leaves of llm9428 compared to its wild type (WT). The llm9428 showed enhanced blast disease resistance and increased relative expression of pathogenesis-related (PR) genes. Studies of the sub-cellular structure of the leaf and quantification of starch contents revealed a significant decrease in starch granule formation in llm9428. Genetic analysis revealed a single nucleotide change (C > T) that altered an amino acid (Ala > Val) in the candidate gene (Os03g0131200) encoding a CATALASE C in llm9428. CRISPR-Cas9 targetted knockout lines of LLM9428/OsCATC showed the phenotype of LMMs and reduced starch metabolism. Taken together, the current study results revealed a novel role of OsCATC in starch metabolism in addition to validating previously studied functions of CATs.


Asunto(s)
Oryza , Resistencia a la Enfermedad/genética , Regulación de la Expresión Génica de las Plantas , Peróxido de Hidrógeno/metabolismo , Mutación , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Almidón/metabolismo
5.
BMC Genomics ; 23(1): 278, 2022 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-35392815

RESUMEN

BACKGROUND: Rice sheath blight, caused by Rhizoctonia solani Kühn (teleomorph: Thanatephorus cucumeris), is one of the most severe diseases in rice (Oryza sativa L.) worldwide. Studies on resistance genes and resistance mechanisms of rice sheath blight have mainly focused on indica rice. Rice sheath blight is a growing threat to rice production with the increasing planting area of japonica rice in Northeast China, and it is therefore essential to explore the mechanism of sheath blight resistance in this rice subspecies. RESULTS: In this study, RNA-seq technology was used to analyse the gene expression changes of leaf sheath at 12, 24, 36, 48, and 72 h after inoculation of the resistant cultivar 'Shennong 9819' and susceptible cultivar 'Koshihikari' with R. solani. In the early stage of R. solani infection of rice leaf sheaths, the number of differentially expressed genes (DEGs) in the inoculated leaf sheaths of resistant and susceptible cultivars showed different regularity. After inoculation, the number of DEGs in the resistant cultivar fluctuated, while the number of DEGs in the susceptible cultivar increased first and then decreased. In addition, the number of DEGs in the susceptible cultivar was always higher than that in the resistant cultivar. After inoculation with R. solani, the overall transcriptome changes corresponding to multiple biological processes, molecular functions, and cell components were observed in both resistant and susceptible cultivars. These included metabolic process, stimulus response, biological regulation, catalytic activity, binding and membrane, and they were differentially regulated. The phenylalanine metabolic pathway; tropane, piperidine, and pyridine alkaloid biosynthesis pathways; and plant hormone signal transduction were significantly enriched in the early stage of inoculation of the resistant cultivar Shennong 9819, but not in the susceptible cultivar Koshihikari. This indicates that the response of the resistant cultivar Shennong 9819 to pathogen stress was faster than that of the susceptible cultivar. The expression of plant defense response marker PR1b gene, transcription factor OsWRKY30 and OsPAL1 and OsPAL6 genes that induce plant resistance were upregulated in the resistant cultivar. These data suggest that in the early stage of rice infection by R. solani, there is a pathogen-induced defence system in resistant rice cultivars, involving the expression of PR genes, key transcription factors, PAL genes, and the enrichment of defence-related pathways. CONCLUSION: The transcriptome data revealed the molecular and biochemical differences between resistant and susceptible cultivars of rice after inoculation with R. solani, indicating that resistant cultivars have an immune response mechanism in the early stage of pathogen infection. Disease resistance is related to the overexpression of PR genes, key transcriptome factors, and PAL genes, which are potential targets for crop improvement.


Asunto(s)
Oryza , Oryza/metabolismo , Enfermedades de las Plantas/genética , Rhizoctonia/genética , Factores de Transcripción/metabolismo , Transcriptoma
6.
BMC Genomics ; 23(1): 251, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35365095

RESUMEN

BACKGROUND: When plants are subjected to cold stress, they undergo a series of molecular and physiological changes to protect themselves from injury. Indica cultivars can usually withstand only mild cold stress in a relatively short period. Hormone-mediated defence response plays an important role in cold stress. Weighted gene co-expression network analysis (WGCNA) is a very useful tool for studying the correlation between genes, identifying modules with high phenotype correlation, and identifying Hub genes in different modules. Many studies have elucidated the molecular mechanisms of cold tolerance in different plants, but little information about the recovery process after cold stress is available. RESULTS: To understand the molecular mechanism of cold tolerance in rice, we performed comprehensive transcriptome analyses during cold treatment and recovery stage in two cultivars of near-isogenic lines (9311 and DC907). Twelve transcriptomes in two rice cultivars were determined. A total of 2509 new genes were predicted by fragment splicing and assembly, and 7506 differentially expressed genes were identified by pairwise comparison. A total of 26 modules were obtained by expression-network analysis, 12 of which were highly correlated with cold stress or recovery treatment. We further identified candidate Hub genes associated with specific modules and analysed their regulatory relationships based on coexpression data. Results showed that various plant-hormone regulatory genes acted together to protect plants from physiological damage under short-term low-temperature stress. We speculated that this may be common in rice. Under long-term cold stress, rice improved the tolerance to low-temperature stress by promoting autophagy, sugar synthesis, and metabolism. CONCLUSION: Through WGCNA analysis at the transcriptome level, we provided a potential regulatory mechanism for the cold stress and recovery of rice cultivars and identified candidate central genes. Our findings provided an important reference for the future cultivation of rice strains with good tolerance.


Asunto(s)
Oryza , Respuesta al Choque por Frío/genética , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Redes Reguladoras de Genes , Oryza/metabolismo
7.
Mol Plant ; 15(4): 740-754, 2022 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-35381198

RESUMEN

N-terminal acetylation is one of the most common protein modifications in eukaryotes, and approximately 40% of human and plant proteomes are acetylated by ribosome-associated N-terminal acetyltransferase A (NatA) in a co-translational manner. However, the in vivo regulatory mechanism of NatA and the global impact of NatA-mediated N-terminal acetylation on protein fate remain unclear. Here, we identify Huntingtin Yeast partner K (HYPK), an evolutionarily conserved chaperone-like protein, as a positive regulator of NatA activity in rice. We found that loss of OsHYPK function leads to developmental defects in rice plant architecture but increased resistance to abiotic stresses, attributable to perturbation of the N-terminal acetylome and accelerated global protein turnover. Furthermore, we demonstrated that OsHYPK is also a substrate of NatA and that N-terminal acetylation of OsHYPK promotes its own degradation, probably through the Ac/N-degron pathway, which could be induced by abiotic stresses. Taken together, our findings suggest that the OsHYPK-NatA complex plays a critical role in coordinating plant development and stress responses by dynamically regulating NatA-mediated N-terminal acetylation and global protein turnover, which are essential for maintaining adaptive phenotypic plasticity in rice.


Asunto(s)
Oryza , Acetilación , Acetiltransferasas/genética , Acetiltransferasas/metabolismo , Acetiltransferasa A N-Terminal/metabolismo , Oryza/genética , Oryza/metabolismo , Desarrollo de la Planta , Estrés Fisiológico
8.
Plant Signal Behav ; 17(1): 2065432, 2022 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-35442849

RESUMEN

The OsPIN1 paralogous genes (OsPIN1a-1d) are important for root and panicle development in rice (Oryza sativa L.). However, the specific role of OsPIN1 paralogous genes is still not clear. To understand the specific roles of PIN1 paralogs in rice, we generated pin1 triple and quadruple mutants by crossing the pin1a pin1b and pin1c pin1d double mutants which we previously created. Compared with the 7-day-old wild type, the pin1a pin1c pin1d and pin1b pin1c pin1d triple mutants showed no obvious phenotype variation except that the pin1a pin1c pin1d triple mutant had shorter primary root and shoot. The pin1a pin1b pin1c and pin1a pin1b pin1d triple mutants exhibited a series of developmental abnormalities, including shorter primary roots, longer root hairs, fewer crown roots and lateral roots, shorter and curved shoots. Furthermore, the pin1a pin1b pin1c pin1d quadruple mutant displayed more severe phenotypic defects which was lethal. In addition, the expression levels of some hormone signal transduction and crown root development related genes, such as OsIAAs, OsARFs, OsRRs, and OsCRLs, were significantly altered in the stem base of all examined pin1 multiple mutants. Taken together, our results demonstrated that the four OsPIN1 paralogous genes function redundantly in regulating rice growth and development.


Asunto(s)
Oryza , Regulación de la Expresión Génica de las Plantas/genética , Crecimiento y Desarrollo , Ácidos Indolacéticos/metabolismo , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/metabolismo
9.
Food Funct ; 13(9): 5430-5441, 2022 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-35475442

RESUMEN

Dietary protein is crucial for maintaining body growth and plays a significant role in shaping the gut microbiota. Rice bran (RB) rancidity can induce rice bran protein (RBP) oxidation and change the structural characteristics, which further impacts the functional properties and nutritional value of RBP. Therefore, the impact of rancidity-induced RBP oxidation on the gut microbiota and intestinal permeability was evaluated. Oxidized RBP significantly altered the α-diversity of the gut microbiota and impacted the microbial profile at phylum and genus levels, and moderately oxidized RBP caused increasing abundance of Akkermansia and reducing abundance of Desulfovibrio. Different oxidation extents of RBP induced different biomarkers, indicating that the composition of the gut microbiota presented an oxidation extent-dependent pattern. Oxidized RBP also significantly promoted the level of formic acid and reduced the level of isovaleric acid. Moreover, oxidized RBP significantly upregulated the expression of genes related to tight junction proteins. The phenomena indicated that oxidized RBP significantly changed the composition of the gut microbiota and improved the barrier function of the intestine, while showing fewer effects on the production of short-chain fatty acids (SCFAs). The research provides a theoretical reference for understanding the effects of plant protein oxidation on intestinal health during food storage and processing.


Asunto(s)
Microbioma Gastrointestinal , Oryza , Animales , Ácidos Grasos Volátiles/metabolismo , Intestinos , Ratones , Oryza/metabolismo , Permeabilidad
10.
Ecotoxicol Environ Saf ; 237: 113526, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35453023

RESUMEN

Cell wall pectin is essential for cadmium (Cd) accumulation in rice roots and hydrogen peroxide (H2O2) plays an important role as a signaling molecule in cell wall modification. The role of H2O2 in Cd binding in cell wall pectin is unclear. D62B, a Cd-safe rice line, was found to show a greater Cd binding capacity in the root cell wall than a high Cd-accumulating rice line of Wujin4B. In this study, we further investigated the mechanism of the role of H2O2 in Cd binding in root cell wall pectin of D62B compared with Wujin4B. Cd treatment significantly increased the H2O2 concentration and pectin methyl esterase (PME) activity in the roots of D62B and Wujin4B by 22.45-42.44% and 12.15-15.07%, respectively. The H2O2 concentration and PME activity significantly decreased in the roots of both rice lines when H2O2 was scavenged by 4-hydroxy-Tempo. The PME activity of D62B was higher than that of Wujin4B. The concentrations of high and low methyl-esterified pectin in the roots of D62B significantly increased when exposed to Cd alone but significantly decreased when exposed to Cd and exogenous 4-hydroxy-Tempo. No significant difference was detected in Wujin4B. Exogenous 4-hydroxy-Tempo significantly decreased the Cd concentration in the cell wall pectin in both rice lines. The modification of H2O2 in Cd binding was further explored by adding H2O2. The maximum Cd adsorption amounts on the root cell walls of both rice lines were improved by exogenous H2O2·H2O2 treatment significantly influenced the relative peak area of the main functional groups (hydroxyl, carboxyl), and the groups intensely shifted after Cd adsorption in the root cell wall of D62B, while there was no significant difference in Wujin4B. In conclusion, Cd stress stimulated the production of H2O2, thus promoting pectin biosynthesis and demethylation and releasing relative functional groups involved in Cd binding on cell wall pectin, which is beneficial for Cd retention in the roots of Cd-safe rice line.


Asunto(s)
Oryza , Contaminantes del Suelo , Cadmio/metabolismo , Pared Celular/metabolismo , Peróxido de Hidrógeno/metabolismo , Oryza/metabolismo , Pectinas/metabolismo , Raíces de Plantas/metabolismo , Contaminantes del Suelo/análisis
11.
Ecotoxicol Environ Saf ; 237: 113530, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35462194

RESUMEN

Cadmium (Cd) is a toxic heavy metal that can accumulate in crop plants. We reported previously the engineering of a low cadmium-accumulating line (2B) of rice through overexpression of a truncated OsO3L2 gene. As expression of this transgene was highest in plant roots, amplicon and metatranscriptome sequencing were used to investigate the possibility that its expression affects root associated microbes. Based on amplicon sequencing of bacterial 16S rRNA, but less so from fungal ITS, the OTUs (operational taxonomic units) showed less diversity in soil tightly (rhizoplane) than loosely (rhizosphere) associated with plant roots. Significantly changed OTUs caused by the low-Cd accumulating plant 2B, Cd treatment or both were found, and 10 of the 13 OTUs (77%) that were enriched in Cd treated 2B samples over the wild type counterpart have been previously described as involved in tolerance to Cd or other heavy metals. Metatranscriptome sequencing of rhizosphere microbiome found that bacteria accounted for 70-75% of the microbial RNA. Photosynthesis-antenna proteins and nitrogen metabolism pathways were most active in soil microbes treated with Cd and grown with plant 2B. Correspondingly, the relative abundance of Cyanobacteria was enriched to < 1% of Cd treated rhizosphere bacteria, yet accounted for up to 13% of Cd treated 2B rhizospheric transcripts. These enriched microbes by transgene and Cd are worthy candidates for future application on reducing crop uptake of Cd.


Asunto(s)
Microbiota , Oryza , Contaminantes del Suelo , Bacterias/metabolismo , Cadmio/metabolismo , Microbiota/genética , Oryza/genética , Oryza/metabolismo , Raíces de Plantas/metabolismo , ARN Ribosómico 16S/genética , Rizosfera , Suelo , Microbiología del Suelo , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad , Transgenes
12.
Development ; 149(9)2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35394032

RESUMEN

Shoot-borne adventitious/crown roots form a highly derived fibrous root system in grasses. The molecular mechanisms controlling their development remain largely unknown. Here, we provide a genome-wide landscape of transcriptional signatures - tightly regulated auxin response and in-depth spatio-temporal expression patterns of potential epigenetic modifiers - and transcription factors during priming and outgrowth of rice (Oryza sativa) crown root primordia. Functional analyses of rice transcription factors from WUSCHEL-RELATED HOMEOBOX and PLETHORA gene families reveal their non-redundant and species-specific roles in determining the root architecture. WOX10 and PLT1 regulate both shoot-borne crown roots and root-borne lateral roots, but PLT2 specifically controls lateral root development. PLT1 activates local auxin biosynthesis genes to promote crown root development. Interestingly, O. sativa PLT genes rescue lateral root primordia outgrowth defects of Arabidopsis plt mutants, demonstrating their conserved role in root primordia outgrowth irrespective of their developmental origin. Together, our findings unveil a molecular framework of tissue transdifferentiation during root primordia establishment, leading to the culmination of robust fibrous root architecture. This also suggests that conserved factors have evolved their transcription regulation to acquire species-specific function.


Asunto(s)
Arabidopsis , Oryza , Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas/genética , Ácidos Indolacéticos/metabolismo , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
13.
Cells ; 11(7)2022 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-35406707

RESUMEN

Nutritional quality improvement of rice is the key to ensure global food security. Consequently, enormous efforts have been made to develop genomics and transcriptomics resources for rice. The available omics resources along with the molecular understanding of trait development can be utilized for efficient exploration of genetic resources for breeding programs. In the present study, 80 genes known to regulate the nutritional and cooking quality of rice were extensively studied to understand the haplotypic variability and gene expression dynamics. The haplotypic variability of selected genes were defined using whole-genome re-sequencing data of ~4700 diverse genotypes. The analytical workflow identified 133 deleterious single-nucleotide polymorphisms, which are predicted to affect the gene function. Furthermore, 788 haplotype groups were defined for 80 genes, and the distribution and evolution of these haplotype groups in rice were described. The nucleotide diversity for the selected genes was significantly reduced in cultivated rice as compared with that in wild rice. The utility of the approach was successfully demonstrated by revealing the haplotypic association of chalk5 gene with the varying degree of grain chalkiness. The gene expression atlas was developed for these genes by analyzing RNA-Seq transcriptome profiling data from 102 independent sequence libraries. Subsequently, weighted gene co-expression meta-analyses of 11,726 publicly available RNAseq libraries identified 19 genes as the hub of interactions. The comprehensive analyses of genetic polymorphisms, allelic distribution, and gene expression profiling of key quality traits will help in exploring the most desired haplotype for grain quality improvement. Similarly, the information provided here will be helpful to understand the molecular mechanism involved in the development of nutritional and cooking quality traits in rice.


Asunto(s)
Oryza , Culinaria , Grano Comestible , Expresión Génica , Haplotipos/genética , Nucleótidos/metabolismo , Oryza/genética , Oryza/metabolismo , Sitios de Carácter Cuantitativo
14.
Plant Sci ; 319: 111257, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35487665

RESUMEN

Cytokinin oxidase/dehydrogenases (CKXs) are key enzymes that degrade cytokinins (CTKs) and play an essential role in plant growth and development. The present study analyzed the phenotypic and physiological characteristics of OsCKX2 overexpressing (OE) and knockout (KO) rice plants after exposure to phosphate (Pi) deficiency and the transcriptome and metabolome to investigate the function of OsCKX2 in response to Pi deficiency. OsCKX2 KO plants demonstrated higher endogenous CTK levels than wild-type (WT) under Pi deficiency. Further analysis indicated more robust tolerance of OsCKX2 KO plants to Pi deficiency, which exhibited higher phosphorus concentration, larger shoot biomass, and lesser leaf yellowing under Pi deficiency; whereas the opposite was observed for OsCKX2 OE plants. Transcriptome and metabolome analyses revealed that overexpression of OsCKX2 downregulated the transcriptional levels of genes related to Pi transporters, membrane lipid metabolism, and glycolysis, and reduced the consumption of metabolites in membrane lipid metabolism and glycolysis. On the contrary, knockout of OsCKX2 upregulated the expression of Pi transporters, and increased the consumption of metabolites in membrane lipid metabolism and glycolysis. These results indicated that OsCKX2 impacted Pi uptake, recycling, and plant growth via Pi transporters, phospholipid hydrolysis, and glycolysis under Pi deficiency. Overall, OsCKX2 negatively regulated Pi deficiency tolerance by modulating CTKs in rice.


Asunto(s)
Oryza , Citocininas/metabolismo , Oryza/metabolismo , Fosfatos/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Proteínas de Plantas/metabolismo
15.
J Agric Food Chem ; 70(15): 4599-4610, 2022 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-35385284

RESUMEN

Agricultural chemical residues in farmland and crops is one of the serious public issues that constantly threatens crop production, food security, and human health. Understanding their decay mechanism in crops for accelerating their degradative metabolism is important. In this study, a rice uncharacterized cytochrome P450 gene encoding CYP76C6 was functionally identified in rice exposed to isoproturon (IPU). To verify the role of CYP76C6 in rice resistance to IPU toxicity, CYP76C6 overexpression (OEs) and knockout mutant rice by CRISPR/Cas9 were generated through genetic transformation and gene-editing technologies. Assessment of growth and physiological responses revealed that the growth of OE lines was improved, the IPU-induced cellular damage was attenuated, and IPU accumulation was significantly repressed, whereas the Cas9 lines displayed a contrasting phenotype compared to the wild-type. Both relative contents of IPU metabolites and conjugates in OE lines were reduced and those in Cas9 line were increased, suggesting that CYP76C6 plays a critical role in IPU degradation. Our study unveils a new regulator, together with its mechanism for IPU decay in rice crops, which will be used in reality to reduce environmental risks in food safety and human health.


Asunto(s)
Herbicidas , Oryza , Productos Agrícolas/metabolismo , Herbicidas/química , Oryza/genética , Oryza/metabolismo , Compuestos de Fenilurea/metabolismo
16.
Int J Mol Sci ; 23(7)2022 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-35409320

RESUMEN

Rice leaf folder Cnaphalocrocis medinalis is one of the most serious pests of rice in rice-planting regions worldwide. DsRNA-degrading nucleases (dsRNases) are important factors in reducing the efficiency of RNA interference (RNAi) in different insects. In this study, a dsRNase gene from C. medinalis (CmdsRNase) was cloned and characterized. The CmdsRNase cDNA was 1395 bp in length, encoding 464 amino acids. The CmdsRNase zymoprotein contains a signal peptide and an endonuclease NS domain that comprises six active sites, three substrate-binding sites, and one Mg2+-binding site. The mature CmdsRNase forms a homodimer with a total of 16 α-helices and 20 ß-pleated sheets. Homology and phylogenetic analyses revealed that CmdsRNase is closely related to dsRNase2 in Ostrinia nubilalis. Expression pattern analysis by droplet digital PCR indicated that the expression levels of CmdsRNase varied throughout the developmental stages of C. medinalis and in different adult tissues, with the highest expression levels in the fourth-instar larvae and the hemolymph. CmdsRNase can degrade dsRNA to reduce the efficiency of RNAi in C. medinalis. Co-silencing of CmCHS (chitin synthase from C. medinalis) and CmdsRNase affected significantly the growth and development of C. medinalis and thus improved RNAi efficacy, which increased by 27.17%. These findings will be helpful for green control of C. medinalis and other lepidopteran pests by RNAi.


Asunto(s)
Mariposas Nocturnas , Oryza , Animales , Endonucleasas/metabolismo , Mariposas Nocturnas/genética , Mariposas Nocturnas/metabolismo , Oryza/genética , Oryza/metabolismo , Filogenia , Interferencia de ARN , ARN Bicatenario/genética
17.
Int J Mol Sci ; 23(8)2022 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-35456901

RESUMEN

Brown planthopper (Nilaparvata lugens Stål, BPH) is one of the most destructive insects affecting rice production. To better understand the physiological mechanisms of how rice responds to BPH feeding, we analyzed BPH-induced transcriptomic and metabolic changes in leaf sheaths of both BPH-susceptible and -resistant rice varieties. Our results demonstrated that the resistant rice reduced the settling, feeding and growth of BPH. Metabolic analyses indicated that BPH infestation caused more drastic overall metabolic changes in the susceptible variety than the resistant rice. Differently accumulated metabolites (DAMs) belonging to flavonoids were downregulated in the susceptible rice but upregulated in resistant variety. Transcriptomic analyses revealed more differentially expressed genes (DEGs) in susceptible rice than resistant rice, and DEGs related to stimulus were significantly upregulated in resistant rice but downregulated in susceptible rice. Combined analyses of transcriptome and metabolome showed that many DEGs and DAMs were enriched in phenylpropane biosynthesis, flavonoid biosynthesis, and plant hormone signal transduction. We conducted correlation analyses of DEGs and DAMs in these pathways and found a high correlation between DEGs and DAMs. Then, we found that the contents of endogenous indole 3-acetic acid (IAA) in resistant rice was lower than that of susceptible rice after BPH feeding, while the salicylic acid (SA) content was the opposite. For functional analysis, an exogenous application of IAA decreased rice resistance to BPH, but the exogenous application of SA increased resistance. In addition, biochemical assessment and quantitative PCR analysis showed that the lignin content of resistant accession was constitutively higher than in susceptible accession. By adding epigallocatechin, the substrate of anthocyanidin reductase (ANR), to the artificial diet decreased the performance of BPH. We first combined a transcriptome-metabolome-wide association study (TMWAS) on rice resistance to BPH in this study. We demonstrated that rice promoted resistance to BPH by inducing epigallocatechin and decreasing IAA. These findings provided useful transcriptomic and metabolic information for understanding the rice-BPH interactions.


Asunto(s)
Hemípteros , Oryza , Hiperplasia Prostática , Animales , Regulación de la Expresión Génica de las Plantas , Hemípteros/fisiología , Humanos , Masculino , Metaboloma , Oryza/metabolismo , Ácido Salicílico/metabolismo , Transcriptoma
18.
J Hazard Mater ; 433: 128752, 2022 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-35364530

RESUMEN

The newly deposited mercury (Hg) is more readily methylated to methylmercury (MeHg) than native Hg in paddy soil. However, the biogeochemical processes of the newly deposited Hg in soil are still unknown. Here, a field experimental plot together with a stable Hg isotope tracing technique was used to demonstrate the geochemical fractionation (partitioning and redistribution) of the newly deposited Hg in paddy soils during the rice-growing period. We showed that the majority of Hg tracer (200Hg, 115.09 ± 0.36 µg kg-1) was partitioned as organic matter bound 200Hg (84.6-89.4%), followed by residual 200Hg (7.6-8.1%), Fe/Mn oxides bound 200Hg (2.8-7.2%), soluble and exchangeable 200Hg (0.05-0.2%), and carbonates bound 200Hg (0.04-0.07%) in paddy soils. Correlation analysis and partial least squares path modeling revealed that the coupling of autochthonous dissolved organic matter and poorly crystalline Fe (oxyhydr)oxides played a predominant role in controlling the redistribution of the newly deposited Hg among geochemical fractions (i.e., fraction changes). The expected aging processes of the newly deposited Hg were absent, potentially explaining the high bioavailability of these Hg in paddy soil. This study implies that other Hg pools (e.g., organic matter bound Hg) should be considered instead of merely soluble Hg pools when evaluating the environmental risks of Hg from atmospheric depositions.


Asunto(s)
Mercurio , Compuestos de Metilmercurio , Oryza , Contaminantes del Suelo , Monitoreo del Ambiente , Isótopos/análisis , Isótopos/metabolismo , Mercurio/análisis , Compuestos de Metilmercurio/análisis , Oryza/metabolismo , Óxidos/metabolismo , Suelo/química , Contaminantes del Suelo/metabolismo
19.
Ecotoxicol Environ Saf ; 236: 113479, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35366561

RESUMEN

Effects of iron and sulfur redox states in the soil caused by different growth seasons on Cd uptake by rice remain unclear. In this study, three early rice cultivars and three late rice cultivars were cultivated in a double-cropping system in Cd-contaminated paddy fields. The total Cd accumulation of early rice cultivars was 20.5-51.1 µg plant-1, and the Cd concentration in grains was 0.19-0.73 mg kg-1, significantly lower than those of late rice cultivars by 8-15 times and 3-9 times, respectively. The filling and mature stages were identified as the most crucial stages of Cd uptake by both early and late rice cultivars. The growth season of early rice cultivars was characterized by more abundant rainfall and lower soil Eh than that for late rice cultivars. Therefore, the abundances of Fe-reducing bacteria (FeRB, 36.9-39%) and S-reducing bacteria (SRB, 1.77-2.79%) were higher during the filling and mature stages of early rice. They primarily belonged to the Clostridium, Geobacter, and Desulfuromonadales genera. Stimulation of FeRB and SRB activity promoted Fe(III) and S reduction and increased the content of Fe2+ and S2- in rhizosphere soil. This promoted the binding of Cd to amorphous Fe oxides and sulfides or Fe sulfides, thereby decreasing the available Cd content. Moreover, the Cd in the iron plaque (IP) and Cd transfer from IP to roots were lower in early rice. These findings suggest that maintaining high moisture content in the soil during the filling and mature stages, especially for late rice cultivars, could efficiently reduce Cd uptake by rice planted in contaminated soil.


Asunto(s)
Oryza , Contaminantes del Suelo , Cadmio/metabolismo , Hierro/química , Oryza/metabolismo , Estaciones del Año , Suelo/química , Contaminantes del Suelo/análisis , Sulfuros/metabolismo , Azufre/metabolismo
20.
Sci Rep ; 12(1): 6736, 2022 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-35468979

RESUMEN

Moderate leaf rolling helps to form the ideotype of rice. In this study, six independent OsRUS1-GFP overexpression (OsRUS1-OX) transgenic rice lines with rapid and dynamic leaf rolling phenotype in response to sunlight were constructed. However, the mechanism is unknown. Here, RNA-Seq approach was utilized to identify differentially expressed genes between flag leaves of OsRUS1-OX and wildtype under sunlight. 2920 genes were differentially expressed between OsRUS1-OX and WT, of which 1660 upregulated and 1260 downregulated. Six of the 16 genes in GO: 0009415 (response to water stimulus) were significantly upregulated in OsRUS1-OX. The differentially expressed genes between WT and OsRUS1-OX were assigned to 110 KEGG pathways. 42 of the 222 genes in KEGG pathway dosa04075 (Plant hormone signal transduction) were differentially expressed between WT and OsRUS1-OX. The identified genes in GO:0009415 and KEGG pathway dosa04075 were good candidates to explain the leaf rolling phenotype of OsRUS1-OX. The expression patterns of the 15 genes identified by RNA-Seq were verified by qRT-PCR. Based on transcriptomic and qRT-PCR analysis, a mechanism for the leaf rolling phenotype of OsRUS1-OX was proposed. The differential expression profiles between WT and OsRUS1-OX established by this study provide important insights into the molecular mechanism behind the leaf rolling phenotype of OsRUS1-OX.


Asunto(s)
Oryza , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Oryza/genética , Oryza/metabolismo , Hojas de la Planta/metabolismo , Transcriptoma
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