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1.
J Agric Food Chem ; 69(38): 11350-11360, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34528806

RESUMO

The involvement of zinc (Zn) in terms of aroma formation has been rarely investigated. This study shows that the regulation of 2-acetyl-1-pyrroline (2AP) biosynthesis was evaluated in two different rice cultivars under foliar Zn application. The results showed that the 2AP and Zn contents in leaves and grains were improved substantially under foliar Zn application. The 2AP content was positively related to the expression P5CS2 gene, contents of proline, 1-pyrroline, and Δ1-pyrroline-5-carboxylate (P5C), and the activity of pyrroline-5-carboxylate synthase (P5CS) under Zn application in fragrant rice. Multiple transcription factors (TFs) were differently expressed, such as bZIPs, NACs, and MYBs, to play a role under Zn treatments in fragrant rice, suggesting the crucial role of 46 differently expressed TFs in 2AP improvements in fragrant rice. Furthermore, this study showed that the optimal foliar Zn application at a concentration of 30 mg L-1 could increase the 2AP content of aromatic rice and keep the yield stable or increase the yield. TFs were involved in regulating to promote the 2AP formation in aromatic rice under the foliar Zn application. However, the relationship between 2AP biosynthesis pathway genes and TFs in fragrant rice remains to be further studied.


Assuntos
Oryza , Odorantes , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Pirróis , Transcriptoma , Regulação para Cima , Zinco
2.
Planta ; 254(4): 76, 2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34533642

RESUMO

MAIN CONCLUSION: A new molecular mechanism of tetrahydrofolate deformylase involved in the salt response presumably affects mitochondrial and chloroplast function by regulating energy metabolism and accumulation of reactive oxygen species. High salinity severely restrains plant growth and development, consequently leading to a reduction in grain yield. It is therefore critical to identify the components involved in plant salt resistance. In our previous study, we identified a rice leaf early-senescence mutant hpa1, which encodes a formyl tetrahydrofolate deformylase (Xiong et al. in Sci China Life Sci 64(5):720-738, 2021). Here, we report that HPA1 also plays a role in the salt response. To explore the molecular mechanism of HPA1 in salt resistance, we attempted to identify the differentially expressed proteins between wild type and hpa1 mutant for salinity treatment using an iTRAQ-based comparative protein quantification approach. A total of 4598 proteins were identified, of which 279 were significantly altered, including 177 up- and 102 down-regulated proteins. A functional analysis suggested that the 279 differentially expressed proteins are involved mainly in the regulation of oxidative phosphorylation, phenylpropanoid biosynthesis, photosynthesis, posttranslational modifications, protein turnover and energy metabolism. Moreover, a deficiency in HPA1 impaired chlorophyll metabolism and photosynthesis in chloroplasts and affected the electron flow of the electron transport chain in mitochondria. These changes led to abnormal energy metabolism and accumulation of reactive oxygen species, which may affect the permeability and integrity of cell membranes, leading to cell death. In addition, the results were verified by transcriptional or physiological experiments. Our results provide an insight into a new molecular mechanism of the tetrahydrofolate cycle protein formyl tetrahydrofolate deformylase, which is involved in the salt response, presumably by affecting mitochondrial and chloroplast function regulating energy metabolism and accumulation of reactive oxygen species under salt stress.


Assuntos
Oryza , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteômica , Tetra-Hidrofolatos
3.
Planta ; 254(4): 79, 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34542712

RESUMO

MAIN CONCLUSION: HDA704 enhances drought and salt tolerance via stomata-regulated mechanism. HDA704 negatively regulates stomatal aperture and density, repressing the transcription of DST and ABIL2 by histone deacetylation modification. Drought and salinity can damage crop growth and reduce yield. Stomata play an important role in abiotic stress tolerance. In this study on rice, we identified the RPD3/HDA1-type histone deacetylase HDA704 as a positive regulatory factor in drought and salt tolerance. HDA704 was induced by drought and salt stresses. Overexpression of HDA704 in transgenic rice promoted stomatal closure, decreased the number of stomata and slowed down the rate of water loss, consequently resulting in increased drought and salt tolerance. By contrast, knockdown of HDA704 in transgenic rice decreased stomatal closure and accelerated the rate of water loss, leading to decrease drought and salt tolerance. We detected the transcript expression of DST (Drought and Salt Tolerance) and ABIL2 (Abscisic Acid-insensitive Like2), which positively regulate stomatal aperture and density in rice. Our results showed that HDA704 directly binds to DST and ABIL2, repressing their expression via histone deacetylation modification. Collectively, these findings reveal that HDA704 positively regulates drought and salt tolerance by repressing the expression of DST and ABIL2. Our findings provide a new insight into the molecular mechanisms of stomata-regulated abiotic stress tolerance of plants.


Assuntos
Oryza , Ácido Abscísico , Secas , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/genética , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estômatos de Plantas/genética , Estômatos de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Tolerância ao Sal , Estresse Fisiológico
4.
Int J Mol Sci ; 22(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34502220

RESUMO

Phosphorus (P) is an essential macronutrient, playing a role in developmental and metabolic processes in plants. To understand the local and systemic responses of sorghum to inorganic phosphorus (Pi) starvation and the potential of straw and ash for reutilisation in agriculture, we compared two grain (Razinieh) and sweet (Della) sorghum varieties with respect to their morpho-physiological and molecular responses. We found that Pi starvation increased the elongation of primary roots, the formation of lateral roots, and the accumulation of anthocyanin. In Razinieh, lateral roots were promoted to a higher extent, correlated with a higher expression of SbPht1 phosphate transporters. Infrared spectra of straw from mature plants raised to maturity showed two prominent bands at 1371 and 2337 cm-1, which could be assigned to P-H(H2) stretching vibration in phosphine acid and phosphinothious acid, and their derivates, whose abundance correlated with phosphate uptake of the source plant and genotype (with a higher intensity in Razinieh). The ash generated from these straws stimulated the shoot elongation and root development of the rice seedlings, especially for the material derived from Razinieh raised under Pi starvation. In conclusion, sorghum growing on marginal lands has potential as a bio-economy alternative for mineral phosphorus recycling.


Assuntos
Oryza/crescimento & desenvolvimento , Fósforo/metabolismo , Desenvolvimento Vegetal , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/crescimento & desenvolvimento , Sorghum/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/metabolismo , Proteínas de Transporte de Fosfato/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Sorghum/química , Estresse Fisiológico
5.
Nat Commun ; 12(1): 5479, 2021 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-34531388

RESUMO

The Xanthomonas outer protein C2 (XopC2) family of bacterial effectors is widely found in plant pathogens and Legionella species. However, the biochemical activity and host targets of these effectors remain enigmatic. Here we show that ectopic expression of XopC2 promotes jasmonate signaling and stomatal opening in transgenic rice plants, which are more susceptible to Xanthomonas oryzae pv. oryzicola infection. Guided by these phenotypes, we discover that XopC2 represents a family of atypical kinases that specifically phosphorylate OSK1, a universal adaptor protein of the Skp1-Cullin-F-box ubiquitin ligase complexes. Intriguingly, OSK1 phosphorylation at Ser53 by XopC2 exclusively increases the binding affinity of OSK1 to the jasmonate receptor OsCOI1b, and specifically enhances the ubiquitination and degradation of JAZ transcription repressors and plant disease susceptibility through inhibiting stomatal immunity. These results define XopC2 as a prototypic member of a family of pathogenic effector kinases and highlight a smart molecular mechanism to activate jasmonate signaling.


Assuntos
Proteínas de Bactérias/metabolismo , Oryza/metabolismo , Fosfotransferases/metabolismo , Proteínas de Plantas/metabolismo , Estômatos de Plantas/metabolismo , Xanthomonas/enzimologia , Proteínas de Bactérias/genética , Resistência à Doença/genética , Interações Hospedeiro-Patógeno , Oryza/genética , Fosforilação , Fosfotransferases/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Estômatos de Plantas/genética , Estômatos de Plantas/microbiologia , Plantas Geneticamente Modificadas , Xanthomonas/genética , Xanthomonas/fisiologia
6.
BMC Plant Biol ; 21(1): 406, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488627

RESUMO

BACKGROUND: Plant mitochondrial transcription termination factor (mTERF) family members play important roles in development and stress tolerance through regulation of organellar gene expression. However, their molecular functions have yet to be clearly defined. RESULTS: Here an mTERF gene V14 was identified by fine mapping using a conditional albino mutant v14 that displayed albinism only in the first two true leaves, which was confirmed by transgenic complementation tests. Subcellular localization and real-time PCR analyses indicated that V14 encodes a chloroplastic protein ubiquitously expressed in leaves while spiking in the second true leaf. Chloroplastic gene expression profiling in the pale leaves of v14 through real-time PCR and Northern blotting analyses showed abnormal accumulation of the unprocessed transcripts covering the rpoB-rpoC1 and/or rpoC1-rpoC2 intercistronic regions accompanied by reduced abundance of the mature rpoC1 and rpoC2 transcripts, which encode two core subunits of the plastid-encoded plastid RNA polymerase (PEP). Subsequent immunoblotting analyses confirmed the reduced accumulation of RpoC1 and RpoC2. A light-inducible photosynthetic gene psbD was also found down-regulated at both the mRNA and protein levels. Interestingly, such stage-specific aberrant posttranscriptional regulation and psbD expression can be reversed by high temperatures (30 ~ 35 °C), although V14 expression lacks thermo-sensitivity. Meanwhile, three V14 homologous genes were found heat-inducible with similar temporal expression patterns, implicating their possible functional redundancy to V14. CONCLUSIONS: These data revealed a critical role of V14 in chloroplast development, which impacts, in a stage-specific and thermo-sensitive way, the appropriate processing of rpoB-rpoC1-rpoC2 precursors and the expression of certain photosynthetic proteins. Our findings thus expand the knowledge of the molecular functions of rice mTERFs and suggest the contributions of plant mTERFs to photosynthesis establishment and temperature acclimation.


Assuntos
Oryza/metabolismo , Fotossíntese/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Plântula/fisiologia , Aclimatação , Cloroplastos/fisiologia , Regulação da Expressão Gênica de Plantas , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/genética , Temperatura
7.
G3 (Bethesda) ; 11(9)2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34544147

RESUMO

Threonyl-tRNA synthetase (ThrRS), one of the aminoacyl-tRNA synthetases (AARSs), plays a crucial role in protein synthesis. However, the AARS functions on rice chloroplast development and growth were not fully appraised. In this study, a thermo-sensitive virescent mutant tsv2, which showed albino phenotype and lethal after the 4-leaf stage at 20°C but recovered to normal when the temperatures rose, was identified and characterized. Map-based cloning and complementation tests showed that TSV2 encoded a chloroplast-located ThrRS protein in rice. The Lys-to-Arg mutation in the anticodon-binding domain hampered chloroplast development under cold stress, while the loss of function of the ThrRS core domain in TSV2 fatally led to seedling death regardless of growing temperatures. In addition, TSV2 had a specific expression in early leaves. Its disruption obviously resulted in the downregulation of certain genes associated with chlorophyll biosynthesis, photosynthesis, and chloroplast development at cold conditions. Our observations revealed that rice nuclear-encoded TSV2 plays an important role in chloroplast development at the early leaf stage under cold stress.


Assuntos
Oryza , Treonina-tRNA Ligase , Cloroplastos/genética , Cloroplastos/metabolismo , Resposta ao Choque Frio , Regulação da Expressão Gênica de Plantas , Mutação , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plântula/genética , Plântula/metabolismo
8.
Bioresour Technol ; 340: 125709, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34375790

RESUMO

The characterized microbial consortium can efficiently degrade rice straw to produce acetic and butyric acids in high yields. The rice straw lost 86.9% in weight and degradation rates of hemicellulose, cellulose, and lignin attained were 97.1%, 86.4% and 70.3% within 12 days, respectively. During biodegradation via fermentation of rice straw, average concentrations of acetic and butyric acids reached 1570 mg/L and 1270 mg/L, accounting for 47.2% and 35.4% of the total volatile fatty acids, respectively. The consortium mainly composed of Prevotella, Cellulosilyticum, Pseudomonas, Clostridium and Ruminococcaceae, etc. Metagenomic analyses indicated that glycoside hydrolases (GHs) were the largest enzyme group with a relative abundance of 54.5%. Various lignocellulose degrading enzymes were identified in the top 30 abundant GHs, and were primarily distributed in the dominant genera (Prevotella, Cellulosilyticum and Clostridium). These results provide a new route for the commercial recycling of rice straw to produce organic acids.


Assuntos
Consórcios Microbianos , Oryza , Butiratos , DNA Ribossômico , Fermentação , Lignina/metabolismo , Metagenoma , Oryza/metabolismo
9.
Biomolecules ; 11(8)2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34439892

RESUMO

Diabetic nephropathy (DN) is the primary cause of end-stage renal disease worldwide. Oxidative stress and mitochondrial dysfunction are central to its pathogenesis. Rice husk, the leftover from the milling process, is a good source of phytochemicals with antioxidant activity. This study evaluated the possible protection of purple rice husk extract (PRHE) against diabetic kidney injury. Type 2 diabetic rats were given vehicle, PRHE, metformin, and PRHE+metformin, respectively, while nondiabetic rats received vehicle. After 12 weeks, diabetic rats developed nephropathy as proven by metabolic alterations (increased blood glucose, insulin, HOMA-IR, triglycerides, cholesterol) and renal abnormalities (podocyte injury, microalbuminuria, increased serum creatinine, decreased creatinine clearance). Treatment with PRHE, metformin, or combination diminished these changes, improved mitochondrial function (decreased mitochondrial swelling, reactive oxygen species production, membrane potential changes), and reduced renal oxidative damage (decreased lipid peroxidation and increased antioxidants). Increased expression of PGC-1α, SIRT3, and SOD2 and decreased expression of Ac-SOD2 correlated with the beneficial outcomes. HPLC revealed protocatechuic acid and cyanidin-3-glucoside as the key components of PRHE. The findings indicate that PRHE effectively protects against the development of DN by retaining mitochondrial redox equilibrium via the regulation of PGC-1α-SIRT3-SOD2 signaling. This study creates an opportunity to develop this agricultural waste into a useful health product for diabetes.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Nefropatias Diabéticas/tratamento farmacológico , Mitocôndrias/efeitos dos fármacos , Oryza/metabolismo , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Animais , Antioxidantes/farmacologia , Masculino , Oxirredução , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Ratos , Ratos Wistar , Sirtuínas/metabolismo , Superóxido Dismutase/metabolismo
10.
Int J Mol Sci ; 22(16)2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34445746

RESUMO

Nitrogen is an important factor limiting the growth and yield of rice. However, the excessive application of nitrogen will lead to water eutrophication and economic costs. To create rice varieties with high nitrogen use efficiency (NUE) has always been an arduous task in rice breeding. The processes for improving NUE include nitrogen uptake, nitrogen transport from root to shoot, nitrogen assimilation, and nitrogen redistribution, with each step being indispensable to the improvement of NUE. Here, we summarize the effects of absorption, transport, and metabolism of nitrate, ammonium, and amino acids on NUE, as well as the role of hormones in improving rice NUE. Our discussion provide insight for further research in the future.


Assuntos
Nitrogênio/metabolismo , Oryza/genética , Oryza/metabolismo , Aminoácidos/metabolismo , Compostos de Amônio/metabolismo , Redes Reguladoras de Genes , Variação Genética , Nitratos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo
11.
Int J Mol Sci ; 22(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34360953

RESUMO

Cadmium (Cd), a heavy metal toxic to humans, easily accumulates in rice grains. Rice with unacceptable Cd content has become a serious food safety problem in many rice production regions due to contaminations by industrialization and inappropriate waste management. The development of rice varieties with low grain Cd content is seen as an economic and long-term solution of this problem. The cation/H+ exchanger (CAX) family has been shown to play important roles in Cd uptake, transport and accumulation in plants. Here, we report the characterization of the rice CAX family. The six rice CAX genes all have homologous genes in Arabidopsis thaliana. Phylogenetic analysis identified two subfamilies with three rice and three Arabidopsis thaliana genes in both of them. All rice CAX genes have trans-member structures. OsCAX1a and OsCAX1c were localized in the vacuolar while OsCAX4 were localized in the plasma membrane in rice cell. The consequences of qRT-PCR analysis showed that all the six genes strongly expressed in the leaves under the different Cd treatments. Their expression in roots increased in a Cd dose-dependent manner. GUS staining assay showed that all the six rice CAX genes strongly expressed in roots, whereas OsCAX1c and OsCAX4 also strongly expressed in rice leaves. The yeast (Saccharomyces cerevisiae) cells expressing OsCAX1a, OsCAX1c and OsCAX4 grew better than those expressing the vector control on SD-Gal medium containing CdCl2. OsCAX1a and OsCAX1c enhanced while OsCAX4 reduced Cd accumulation in yeast. No auto-inhibition was found for all the rice CAX genes. Therefore, OsCAX1a, OsCAX1c and OsCAX4 are likely to involve in Cd uptake and translocation in rice, which need to be further validated.


Assuntos
Antiporters/metabolismo , Cádmio/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Resistência a Medicamentos , Oryza/genética , Proteínas de Plantas/metabolismo , Antiporters/genética , Cádmio/toxicidade , Proteínas de Transporte de Cátions/genética , Transporte de Íons , Oryza/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/metabolismo
12.
Int J Mol Sci ; 22(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34360958

RESUMO

Semi-dwarfism is a main agronomic trait in crop breeding. In this study, we performed genome-wide association study (GWAS) and identified a new quantitative trait nucleotide (QTN) for rice shoot length. The peak QTN (C/T) was located in the first coding region of a group III WRKY transcription factor OsWRKY21 (LOC_Os01g60640). Interestingly, further haplotype analysis showed that C/T difference only existed in the indica group but not in the japonica group, resulting in significant differences in plant height among the different indica rice varieties. OsWRKY21 was expressed in embryo, radicle, shoots, leaves, and stems. Most notably, overexpressing OsWRKY21 resulted in the semi-dwarf phenotype, early heading date and short internodes compared to the wild type, while the knockout mutant plants by CRISPR/Cas9 technology yielded the opposite. The overexpressing lines exhibited the decreased length of the cells near sclerenchyma epidermis, accompanied with the lower levels of indole-3-acetic acid (IAA) and gibberellin 3 (GA3), but increased levels of the abscisic acid (ABA) and salicylic acid (SA) in the internodes at heading stage. Moreover, the semi-dwarf phenotype could be fully rescued by exogenous GA3 application at seedling stage. The RNA-seq and qRT-PCR analysis confirmed the differential expression levels of genes in development and the stress responses in rice, including GA metabolism (GA20ox2, GA2ox6, and YABY1) and cell wall biosynthesis (CesA4, 7, and 9) and regulation (MYB103L). These data suggest the essential role of OsWRKY21 in regulation of internode elongation and plant height in rice.


Assuntos
Oryza/genética , Proteínas de Plantas/genética , Caules de Planta/crescimento & desenvolvimento , Locos de Características Quantitativas , Fatores de Transcrição/genética , Estudo de Associação Genômica Ampla , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Melhoramento Vegetal , Reguladores de Crescimento de Plantas/metabolismo , Caules de Planta/genética , Característica Quantitativa Herdável
13.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360743

RESUMO

Under natural environments, light quality and quantity are extremely varied. To respond and acclimate to such changes, plants have developed a multiplicity of molecular regulatory mechanisms. Non-photochemical quenching of chlorophyll fluorescence (NPQ) and thylakoid protein phosphorylation are two mechanisms that protect vascular plants. To clarify the role of thylakoid protein phosphorylation in energy-dependent quenching of chlorophyll fluorescence (qE) in rice plants, we used a direct Western blot assay after BN-PAGE to detect all phosphoproteins by P-Thr antibody as well as by P-Lhcb1 and P-Lhcb2 antibodies. Isolated thylakoids in either the dark- or the light-adapted state from wild type (WT) and PsbS-KO rice plants were used for this approach to detect light-dependent interactions between PsbS, PSII, and LHCII proteins. We observed that the bands corresponding to the phosphorylated Lhcb1 and Lhcb2 as well as the other phosphorylated proteins were enhanced in the PsbS-KO mutant after illumination. The qE relaxation became slower in WT plants after 10 min HL treatment, which correlated with Lhcb1 and Lhcb2 protein phosphorylation in the LHCII trimers under the same experimental conditions. Thus, we concluded that light-induced phosphorylation of PSII core and Lhcb1/Lhcb2 proteins is enhanced in rice PsbS-KO plants which might be due to more reactive-oxygen-species production in this mutant.


Assuntos
Clorofila/metabolismo , Fluorescência , Complexos de Proteínas Captadores de Luz/metabolismo , Luz , Oryza/metabolismo , Tilacoides/metabolismo , Clorofila/genética , Complexos de Proteínas Captadores de Luz/genética , Oryza/genética , Fosforilação , Complexo de Proteína do Fotossistema II/genética , Complexo de Proteína do Fotossistema II/metabolismo , Tilacoides/genética
14.
Int J Mol Sci ; 22(16)2021 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-34445755

RESUMO

OsFKBP20-1b, a plant-specific cyclophilin protein, has been implicated to regulate pre-mRNA splicing under stress conditions in rice. Here, we demonstrated that OsFKBP20-1b is SUMOylated in a reconstituted SUMOylation system in E.coli and in planta, and that the SUMOylation-coupled regulation was associated with enhanced protein stability using a less SUMOylated OsFKBP20-1b mutant (5KR_OsFKBP20-1b). Furthermore, OsFKBP20-1b directly interacted with OsSUMO1 and OsSUMO2 in the nucleus and cytoplasm, whereas the less SUMOylated 5KR_OsFKBP20-1b mutant had an impaired interaction with OsSUMO1 and 2 in the cytoplasm but not in the nucleus. Under heat stress, the abundance of an OsFKBP20-1b-GFP fusion protein was substantially increased in the nuclear speckles and cytoplasmic foci, whereas the heat-responsiveness was remarkably diminished in the presence of the less SUMOylated 5KR_OsFKBP20-1b-GFP mutant. The accumulation of endogenous SUMOylated OsFKBP20-1b was enhanced by heat stress in planta. Moreover, 5KR_OsFKBP20-1b was not sufficiently associated with the U snRNAs in the nucleus as a spliceosome component. A protoplast transfection assay indicated that the low SUMOylation level of 5KR_OsFKBP20-1b led to inaccurate alternative splicing and transcription under heat stress. Thus, our results suggest that OsFKBP20-1b is post-translationally regulated by SUMOylation, and the modification is crucial for proper RNA processing in response to heat stress in rice.


Assuntos
Resposta ao Choque Térmico , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Splicing de RNA , Sumoilação , Escherichia coli
15.
J Chem Theory Comput ; 17(8): 5342-5357, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34339605

RESUMO

The realism and accuracy of lipid bilayer simulations through molecular dynamics (MD) are heavily dependent on the lipid composition. While the field is pushing toward implementing more heterogeneous and realistic membrane compositions, a lack of high-resolution lipidomic data prevents some membrane protein systems from being modeled with the highest level of realism. Given the additional diversity of real-world cellular membranes and protein-lipid interactions, it is still not fully understood how altering membrane complexity affects modeled membrane protein functions or if it matters over long-timescale simulations. This is especially true for organisms whose membrane environments have little to no computational study, such as the plant plasma membrane. Tackling these issues in tandem, a generalized, realistic, and asymmetric plant plasma membrane with more than 10 different lipid species is constructed herein. Classical MD simulations of pure membrane constructs were performed to evaluate how altering the compositional complexity of the membrane impacted the plant membrane properties. The apo form of a plant sugar transporter, OsSWEET2b, was inserted into membrane models where lipid diversity was calculated in either a size-dependent or size-independent manner. An adaptive sampling simulation regime validated by Markov-state models was performed to capture the gating dynamics of OsSWEET2b in each of these membrane constructs. In comparison to previous OsSWEET2b simulations performed in a pure POPC bilayer, we confirm that simulations performed within a native-like membrane composition alter the stabilization of apo OsSWEET2b conformational states by ∼1 kcal/mol. The free-energy barriers of intermediate conformational states decrease when realistic membrane complexity is simplified, albeit roughly within sampling error, suggesting that protein-specific responses to membranes differ due to altered packing caused by compositional fluctuations. This work serves as a case study where a more realistic bilayer composition makes unbiased conformational sampling easier to achieve than with simplified bilayers.


Assuntos
Membrana Celular/química , Proteínas de Membrana/química , Membrana Celular/metabolismo , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Proteínas de Membrana/metabolismo , Simulação de Dinâmica Molecular , Proteínas de Transporte de Monossacarídeos/química , Proteínas de Transporte de Monossacarídeos/metabolismo , Oryza/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo
16.
J Plant Physiol ; 264: 153484, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34343729

RESUMO

High concentrations of As in contaminated environments pose a serious threat to plant, human, and animal health. In this study, we characterized an As-responsive Really Interesting New Gene (RING) E3 ubiquitin ligase gene under arsenate (AsV) stress, named as Oryza sativa As-Induced RING E3 ligase 3 (OsAIR3). AsV treatment highly induced the expression of OsAIR3. OsAIR3-EYFP was localized to the nucleus in rice protoplasts and exhibited E3 ligase activity. Yeast two-hybrid screening and bimolecular fluorescence complementation and pull-down assays revealed the interaction of OsAIR3 with an O. sativa molybdate transporter (OsMOT1;3) in the plasma membrane and cytoplasm. In addition, an in vitro cell-free degradation assay was performed to demonstrate the degradation of OsMOT1;3 by OsAIR3 via the 26S proteasome system. Heterogeneous overexpression of OsAIR3 in Arabidopsis yielded AsV-tolerant phenotypes, as indicated by the comparison of cotyledon expansion, root elongation, shoot fresh weight, and As accumulation between the OsAIR3-overexpressing and control plants. Collectively, these findings suggest that OsAIR3 positively regulates plant response to AsV stress.


Assuntos
Proteínas de Transporte/metabolismo , Molibdênio/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Arsênio/toxicidade , Oryza/enzimologia , Transcriptoma , Técnicas do Sistema de Duplo-Híbrido
17.
Int J Mol Sci ; 22(15)2021 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-34360691

RESUMO

Two-line hybrid rice systems represent a new technical approach to utilizing the advantages of rice hybrids. However, the mechanism underlying the male sterile-line fertility transition in rice remains unclear. Peiai 64S (PA64S) is a photoperiod- and thermo-sensitive genic male sterile (PTGMS) line in which male sterility manifests at an average temperature above 23.5 °C under long-day (LD) conditions. Nongken 58S (NK58S) is a LD-sensitive genic male sterile (PGMS) rice that is sterile under LD conditions (above 13.75 h-day). In contrast, D52S is a short-day (SD)-PGMS line that manifests male sterility under SD conditions (below 13.5 h-day). In this study, we obtained fertile and sterile plants from all three lines and performed transcriptome analyses on the anthers of the plants. Gene ontology (GO) analysis suggested that the differentially expressed genes identified were significantly enriched in common terms involved in the response to jasmonic acid (JA) and in JA biosynthesis. On the basis of the biochemical and molecular validation of dynamic, tissue-specific changes in JA, indole-3-acetic acid (IAA) levels, gibberellin (GA) levels, and JA biosynthetic enzyme activities and expression, we proposed that JA could play a pivotal role in viable pollen production through its initial upregulation, constant fluctuation and leaf-spikelet signaling under certain fertility-inducing conditions. Furthermore, we also sprayed methyl jasmonate (MEJA) and salicylhydroxamic acid (SHAM) on the plants, thereby achieving fertility reversal in the PGMS lines NK58S and D52S, with 12.91-63.53% pollen fertility changes. Through qPCR and enzyme activity analyses, we identified two key enzymes-allene oxide synthase (AOS) and allene oxide cyclase (AOC)-that were produced and upregulated by 20-500-fold in PGMS in response to spraying; the activities of these enzymes reversed pollen fertility by influencing the JA biosynthetic pathway. These results provide a new understanding of hormone interactions and networks in male-sterile rice based on the role of JA that will help us to better understand the potential regulatory mechanisms of fertility development in rice in the future.


Assuntos
Ciclopentanos/metabolismo , Oxirredutases Intramoleculares/genética , Oryza/metabolismo , Oxilipinas/metabolismo , Pólen/crescimento & desenvolvimento , Transdução de Sinais , Acetatos/farmacologia , Ciclopentanos/farmacologia , Fertilidade , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/fisiologia , Oxilipinas/farmacologia , Proteínas de Plantas/genética , Pólen/metabolismo , Salicilamidas/farmacologia
18.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360554

RESUMO

Leaf angle and grain size are important agronomic traits affecting rice productivity directly and/or indirectly through modulating crop architecture. OsBC1, as a typical bHLH transcription factor, is one of the components comprising a complex formed with LO9-177 and OsBUL1 contributing to modulation of rice leaf inclination and grain size. In the current study, two homologues of OsBC1, OsBCL1 and OsBCL2 were functionally characterized by expressing them under the control of OsBUL1 promoter, which is preferentially expressed in the lamina joint and the spikelet of rice. Increased leaf angle and grain length with elongated cells in the lamina joint and the grain hull were observed in transgenic rice containing much greater gibberellin A3 (GA3) levels than WT, demonstrating that both OsBCL1 and OsBCL2 are positive regulators of cell elongation at least partially through increased GA biosynthesis. Moreover, the cell elongation was likely due to cell expansion rather than cell division based on the related gene expression and, the cell elongation-promoting activities of OsBCL1 and OsBCL2 were functional in a dicot species, Arabidopsis.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza/anatomia & histologia , Fenótipo , Folhas de Planta/anatomia & histologia , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas , Oryza/genética , Oryza/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Transdução de Sinais
19.
J Agric Food Chem ; 69(31): 8634-8648, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34339211

RESUMO

The monocot lineage-specific miR528 was previously established as a multistress regulator. However, it remains largely unclear how miR528 participates in response to salinity stress in rice. Here, we show that miR528 positively regulates rice salt tolerance by down-regulating a gene encoding l-ascorbate oxidase (AO), thereby bolstering up the AO-mediated abscisic acid (ABA) synthesis and ROS scavenging. Overexpression of miR528 caused a substantial increase in ascorbic acid (AsA) and ABA contents but a significant reduction in ROS accumulation, resulting in the enhanced salt tolerance of rice plants. Conversely, knockdown of miR528 or overexpression of AO stimulated the expression of the AO gene, hence lowering the level of AsA, a critical antioxidant that promotes the ABA content but reduces the ROS level, and then compromising rice tolerance to salinity. Together, the findings reveal a novel mechanism of the miR528-AO module-mediated salt tolerance by modulating the processes of AsA and ABA metabolism as well as ROS detoxification, which adds a new regulatory role to the miR528-AO stress defense pathway in rice.


Assuntos
Ácido Abscísico/metabolismo , Ácido Ascórbico/metabolismo , MicroRNAs/genética , Oryza , Tolerância ao Sal , Ascorbato Oxidase , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tolerância ao Sal/genética , Estresse Fisiológico
20.
Int J Mol Sci ; 22(15)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34360677

RESUMO

Inflorescence architecture in rice (Oryza sativa) is mainly determined by spikelets and the branch arrangement. Primary branches initiate from inflorescence meristem in a spiral phyllotaxic manner, and further develop into the panicle branches. The branching patterns contribute largely to rice production. In this study, we characterized a rice verticillate primary branch 1(vpb1) mutant, which exhibited a clustered primary branches phenotype. Gene isolation revealed that VPB1 was a allele of RI, that it encoded a BELL-like homeodomain (BLH) protein. VPB1 gene preferentially expressed in the inflorescence and branch meristems. The arrangement of primary branch meristems was disturbed in the vpb1 mutant. Transcriptome analysis further revealed that VPB1 affected the expression of some genes involved in inflorescence meristem identity and hormone signaling pathways. In addition, the differentially expressed gene (DEG) promoter analysis showed that OsBOPs involved in boundary organ initiation were potential target genes of VPB1 protein. Electrophoretic mobility shift assay (EMSA) and dual-luciferase reporter system further verified that VPB1 protein bound to the promoter of OsBOP1 gene. Overall, our findings demonstrate that VPB1 controls inflorescence architecture by regulating the expression of genes involved in meristem maintenance and hormone pathways and by interacting with OsBOP genes.


Assuntos
Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/metabolismo , Inflorescência/metabolismo , Oryza/metabolismo , Transdução de Sinais , Perfilação da Expressão Gênica , Proteínas de Homeodomínio/genética , Inflorescência/genética , Inflorescência/crescimento & desenvolvimento , Meristema/genética , Meristema/crescimento & desenvolvimento , Meristema/metabolismo , Mutação , Oryza/genética , Oryza/crescimento & desenvolvimento
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