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1.
Plant Sci ; 312: 111055, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34620449

RESUMO

High salt environments can induce stress in different plants. The genes containing the ZAT domain constitute a family that belongs to a branch of the C2H2 family, which plays a vital role in responding to abiotic stresses. In this study, we identified 169 ZAT genes from seven plant species, including 44 ZAT genes from G. hirsutum. Phylogenetic tree analysis divided ZAT genes in six groups with conserved gene structure, protein motifs. Two C2H2 domains and an EAR domain and even chromosomal distribution on At and Dt sub-genome chromosomes of G. hirsutum was observed. GhZAT6 was primarily expressed in the root tissue and responded to NaCl and ABA treatments. Subcellular localization found that GhZAT6 was located in the nucleus and demonstrated transactivation activity during a transactivation activity assay. Arabidopsis transgenic lines overexpressing the GhZAT6 gene showed salt tolerance and grew more vigorously than WT on MS medium supplemented with 100 mmol NaCl. Additionally, the silencing of the GhZAT6 gene in cotton plants showed more obvious leaf wilting than the control plants, which were subjected to 400 mmol NaCl treatment. Next, the expressions of GhAPX1, GhFSD1, GhFSD2, and GhSOS3 were significantly lower in the GhZAT6-silenced plants treated with NaCl than the control. Based on these findings, GhZAT6 may be involved in the ABA pathway and mediate salt stress tolerance by regulating ROS-related gene expression.


Assuntos
Estresse Salino/genética , Estresse Salino/fisiologia , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologia , Dedos de Zinco/genética , Arabidopsis/genética , Arabidopsis/fisiologia , Cacau/genética , Cacau/fisiologia , Produtos Agrícolas/genética , Produtos Agrícolas/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Estudo de Associação Genômica Ampla , Gossypium/genética , Gossypium/fisiologia , Oryza/genética , Oryza/fisiologia , Filogenia , Plantas Geneticamente Modificadas , Sorghum/genética , Sorghum/fisiologia
2.
Nat Commun ; 12(1): 3209, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-34050180

RESUMO

Recent studies have demonstrated that drought leads to dramatic, highly conserved shifts in the root microbiome. At present, the molecular mechanisms underlying these responses remain largely uncharacterized. Here we employ genome-resolved metagenomics and comparative genomics to demonstrate that carbohydrate and secondary metabolite transport functionalities are overrepresented within drought-enriched taxa. These data also reveal that bacterial iron transport and metabolism functionality is highly correlated with drought enrichment. Using time-series root RNA-Seq data, we demonstrate that iron homeostasis within the root is impacted by drought stress, and that loss of a plant phytosiderophore iron transporter impacts microbial community composition, leading to significant increases in the drought-enriched lineage, Actinobacteria. Finally, we show that exogenous application of iron disrupts the drought-induced enrichment of Actinobacteria, as well as their improvement in host phenotype during drought stress. Collectively, our findings implicate iron metabolism in the root microbiome's response to drought and may inform efforts to improve plant drought tolerance to increase food security.


Assuntos
Actinobacteria/metabolismo , Secas , Ferro/metabolismo , Microbiota/fisiologia , Sorghum/fisiologia , Aclimatação , Actinobacteria/genética , Produção Agrícola , Segurança Alimentar , Metagenômica/métodos , Raízes de Plantas/microbiologia , RNA-Seq , Rizosfera , Microbiologia do Solo , Sorghum/microbiologia , Estresse Fisiológico
3.
Int J Mol Sci ; 22(9)2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33919137

RESUMO

Introduction of C4 photosynthetic traits into C3 crops is an important strategy for improving photosynthetic capacity and productivity. Here, we report the research results of a variant line of sorghum-rice (SR) plant with big panicle and high spikelet density by introducing sorghum genome DNA into rice by spike-stalk injection. The whole-genome resequencing showed that a few sorghum genes could be integrated into the rice genome. Gene expression was confirmed for two C4 photosynthetic enzymes containing pyruvate, orthophosphate dikinase and phosphoenolpyruvate carboxykinase. Exogenous sorghum DNA integration induced a series of key traits associated with the C4 pathway called "proto-Kranz" anatomy, including leaf thickness, bundle sheath number and size, and chloroplast size in bundle sheath cells. Significantly, transgenic plants exhibited enhanced photosynthetic capacity resulting from both photosynthetic CO2-concentrating effect and improved energy balance, which led to an increase in carbohydrate levels and productivity. Furthermore, such rice plant exhibited delayed leaf senescence. In summary, this study provides a proof for the feasibility of inducing the transition from C3 leaf anatomy to proto-Kranz by spike-stalk injection to achieve efficient photosynthesis and increase productivity.


Assuntos
Oryza/fisiologia , Fotossíntese , Folhas de Planta/fisiologia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/fisiologia , Sorghum/fisiologia , Dióxido de Carbono/metabolismo , Genoma de Planta , Oryza/anatomia & histologia , Oryza/genética , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/anatomia & histologia , Plantas Geneticamente Modificadas/genética , Sorghum/anatomia & histologia , Sorghum/genética
4.
Mol Biol Rep ; 48(3): 2453-2462, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33755850

RESUMO

Sorghum is an essential food crop for millions of people in the semi-arid regions of the world, where its production is severely limited by drought stress. Drought in the early stages of crop growth and development irreversibly interferes, which leads to poor yield. The effect of drought stress in sorghum was studied at physiological, biochemical, and molecular levels in a set of two genotypes differing in their tolerance to drought. Drought stress was imposed by restraining water for 10 days on 25 days old seedlings. A significant influence of water stress was observed on the considered morpho-physiological and biochemical traits. The genotype DRT1019 exhibited physiological and biochemical indicators of drought avoidance through delayed leaf rolling, osmotic adjustment, ideal gas-exchange system, solute accumulation, an increased level of enzyme synthesis and root trait expression as compared to the ICSV95022 genotype. Furthermore, differences in the metabolite changes viz. total carbohydrate, total amides, and lipids were found between the two genotypes under drought stress. In addition, transcript profiling of potential candidate drought genes such as SbTIP3-1, SbDHN1, SbTPS, and SbDREB1A revealed up-regulation in DRT1019, which corresponded with other important physiological and biochemical parameters exhibited in the genotype. In conclusion, this study provides an improved understanding of whole plant response to drought stress in sorghum. Additionally, our results provide promising candidate genes for drought tolerance in sorghum that can be used as potential markers for drought tolerance breeding programs.


Assuntos
Secas , Sorghum/genética , Sorghum/fisiologia , Estresse Fisiológico/genética , Transcrição Genética , Regulação da Expressão Gênica de Plantas , Genótipo , Nitrato Redutase/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Prolina/metabolismo , Sorghum/anatomia & histologia , Espectroscopia de Infravermelho com Transformada de Fourier
5.
PLoS One ; 16(3): e0249136, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33765103

RESUMO

Crop yield monitoring demonstrated the potential to improve agricultural productivity through improved crop breeding, farm management and commodity planning. Remote and proximal sensing offer the possibility to cut crop monitoring costs traditionally associated with surveys and censuses. Fraction of absorbed photosynthetically active radiation (fAPAR), chlorophyll concentration (CI) and normalized difference vegetation (NDVI) indices were used in crop monitoring, but their comparative performances in sorghum monitoring is lacking. This work aimed therefore at closing this gap by evaluating the performance of machine learning modelling of in-season sorghum biomass yields based on Sentinel-2-derived fAPAR and simpler high-throughput optical handheld meters-derived NDVI and CI calculated from sorghum plants reflectance. Bayesian ridge regression showed good cross-validated performance, and high reliability (R2 = 35%) and low bias (mean absolute prediction error, MAPE = 0.4%) during the validation step. Hand-held optical meter-derived CI and Sentinel-2-derived fAPAR showed comparable effects on machine learning performance, but CI outperformed NDVI and was therefore considered as a good alternative to Sentinel-2's fAPAR. The best times to sample the vegetation indices were the months of June (second half) and July. The results obtained in this work will serve several purposes including improvements in plant breeding, farming management and sorghum biomass yield forecasting at extension services and policy making levels.


Assuntos
Biomassa , Aprendizado de Máquina , Sorghum/crescimento & desenvolvimento , Teorema de Bayes , Clorofila/química , Produtos Agrícolas , Tecnologia de Sensoriamento Remoto , Estações do Ano , Sorghum/fisiologia
6.
Plant Sci ; 304: 110801, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33568300

RESUMO

The N6-methyladenosine (m6A) modification is the most common internal post-transcriptional modification, with important regulatory effects on RNA export, splicing, stability, and translation. Studies on the m6A modifications in plants have focused on Arabidopsis thaliana growth and development. However, A. thaliana is a salt-sensitive and model plant species. Thus, studies aimed at characterizing the role of the m6A modification in the salt stress responses of highly salt-tolerant crop species are needed. Sweet sorghum is cultivated as an energy and forage crop, which is highly suitable for growth on saline-alkaline land. Exploring the m6A modification in sweet sorghum may be important for elucidating the salt-resistance mechanism of crops. In this study, we mapped the m6A modifications in two sorghum genotypes (salt-tolerant M-81E and salt-sensitive Roma) that differ regarding salt tolerance. The m6A modification in sweet sorghum under salt stress was drastically altered, especially in Roma, where the m6A modification on mRNAs of some salt-resistant related transcripts increased, resulting in enhanced mRNA stability, which in turn was involved in the regulation of salt tolerance in sweet sorghum. Although m6A modifications are important for regulating sweet sorghum salt tolerance, the regulatory activity is limited by the initial m6A modification level. Additionally, in M-81E and Roma, the differences in the m6A modifications were much greater than the differences in gene expression levels and are more sensitive. Our study suggests that the number and extent of m6A modifications on the transcripts of salt-resistance genes may be important factors for determining and assessing the salt tolerance of crops.


Assuntos
Adenosina/análogos & derivados , Plantas Tolerantes a Sal/metabolismo , Sorghum/metabolismo , Adenosina/metabolismo , Adenosina/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Raízes de Plantas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Tolerância ao Sal , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/fisiologia , Análise de Sequência de RNA , Sorghum/genética , Sorghum/fisiologia
7.
Sci Rep ; 11(1): 46, 2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-33420129

RESUMO

The stems of bioenergy sorghum hybrids at harvest are > 4 m long, contain > 40 internodes and account for ~ 80% of harvested biomass. In this study, bioenergy sorghum hybrids were grown at four planting densities (~ 20,000 to 132,000 plants/ha) under field conditions for 60 days to investigate the impact shading has on stem growth and biomass accumulation. Increased planting density induced a > 2-fold increase in sorghum internode length and a ~ 22% decrease in stem diameter, a typical shade avoidance response. Shade-induced internode elongation was due to an increase in cell length and number of cells spanning the length of internodes. SbGA3ox2 (Sobic.003G045900), a gene encoding the last step in GA biosynthesis, was expressed ~ 20-fold higher in leaf collar tissue of developing phytomers in plants grown at high vs. low density. Application of GA3 to bioenergy sorghum increased plant height, stem internode length, cell length and the number of cells spanning internodes. Prior research showed that sorghum plants lacking phytochrome B, a key photoreceptor involved in shade signaling, accumulated more GA1 and displayed shade avoidance phenotypes. These results are consistent with the hypothesis that increasing planting density induces expression of GA3-oxidase in leaf collar tissue, increasing synthesis of GA that stimulates internode elongation.


Assuntos
Giberelinas/metabolismo , Oxigenases de Função Mista/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Caules de Planta/crescimento & desenvolvimento , Sorghum/metabolismo , Metabolismo Energético , Regulação da Expressão Gênica de Plantas , Folhas de Planta/enzimologia , Caules de Planta/metabolismo , Sorghum/crescimento & desenvolvimento , Sorghum/fisiologia
8.
Plant Cell Environ ; 44(5): 1611-1626, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33495990

RESUMO

Much effort has been placed on developing microbial inoculants to replace or supplement fertilizers to improve crop productivity and environmental sustainability. However, many studies ignore the dynamics of plant-microbe interactions and the genotypic specificity of the host plant on the outcome of microbial inoculation. Thus, it is important to study temporal plant responses to inoculation in multiple genotypes within a single species. With the implementation of high-throughput phenotyping, the dynamics of biomass and nitrogen (N) accumulation of four sorghum genotypes with contrasting N-use efficiency were monitored upon the inoculation with synthetic microbial communities (SynComs) under high and low-N. Five SynComs comprising bacteria isolated from field grown sorghum were designed based on the overall phylar composition of bacteria and the enriched host compartment determined from a field-based culture independent study of the sorghum microbiome. We demonstrated that the growth response of sorghum to SynCom inoculation is genotype-specific and dependent on plant N status. The sorghum genotypes that were N-use inefficient were more susceptible to the colonization from a diverse set of inoculated bacteria as compared to the N-use efficient lines especially under low-N. By integrating high-throughput phenotyping with sequencing data, our findings highlight the roles of host genotype and plant nutritional status in determining colonization by bacterial synthetic communities.


Assuntos
Bactérias/metabolismo , Microbiota , Nitrogênio/farmacologia , Sorghum/genética , Sorghum/microbiologia , Bactérias/efeitos dos fármacos , Biodiversidade , Clorofila/metabolismo , Genótipo , Fenótipo , Folhas de Planta/microbiologia , Raízes de Plantas/microbiologia , Análise de Componente Principal , Reprodutibilidade dos Testes , Rizosfera , Sorghum/fisiologia , Especificidade da Espécie
9.
Plant Physiol Biochem ; 158: 255-264, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33223387

RESUMO

An open-top chamber experiment was conducted in the present study to investigate the growth and biochemical responses of six sorghum genotypes under two irrigation regimes (based on 40% and 75% soil-water depletion) and two N fertilizer levels (0 and 105 kgN ha-1), at two atmospheric CO2 conditions (390 ± 50 and 700 ± 50 µmol mol-1). The results revealed that water limited stress decreased the plant dry weight by reducing the plant leaf area, SPAD value, Fv/Fm, leaf RWC and membrane stability index (MSI), while it increased the specific activity of APX, CAT and POX enzymes, DPPH, LPC, Phe, TSC, H2O2, MDA and EL. The lowest decrease of the plant dry weight due to limited water stress was observed in the GS5 genotype, which was followed by the lowest decrease in the leaf RWC and MSI; also, the highest increase was seen in APX, Phe and TSC, while the lowest one was recorded in EL. Elevated CO2 improved DPPH and Phe under both control and water limited conditions, resulting in the decrease of APX, POX, H2O2 and EL, while a more pronounced effect was observed in the stress conditions. Furthermore, with the application of nitrogen, the reduction in DPPH, H2O2 and MDA values was greater under water limited stress rather than control conditions. It could be, therefore, concluded that the responses of sorghum genotypes to water deficit stress had interaction with atmospheric CO2 concentrations and nitrogen levels; this could be considered in breeding programs as well as planting management of sorghum.


Assuntos
Dióxido de Carbono/análise , Desidratação , Nitrogênio/análise , Sorghum/fisiologia , Água , Secas , Genótipo , Peróxido de Hidrogênio , Folhas de Planta , Sorghum/genética
10.
Plant Cell Environ ; 44(3): 729-746, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33245145

RESUMO

Elevated tropospheric ozone concentration (O3 ) significantly reduces photosynthesis and productivity in several C4 crops including maize, switchgrass and sugarcane. However, it is unknown how O3 affects plant growth, development and productivity in sorghum (Sorghum bicolor L.), an emerging C4 bioenergy crop. Here, we investigated the effects of elevated O3 on photosynthesis, biomass and nutrient composition of a number of sorghum genotypes over two seasons in the field using free-air concentration enrichment (FACE), and in growth chambers. We also tested if elevated O3 altered the relationship between stomatal conductance and environmental conditions using two common stomatal conductance models. Sorghum genotypes showed significant variability in plant functional traits, including photosynthetic capacity, leaf N content and specific leaf area, but responded similarly to O3 . At the FACE experiment, elevated O3 did not alter net CO2 assimilation (A), stomatal conductance (gs ), stomatal sensitivity to the environment, chlorophyll fluorescence and plant biomass, but led to reductions in the maximum carboxylation capacity of phosphoenolpyruvate and increased stomatal limitation to A in both years. These findings suggest that bioenergy sorghum is tolerant to O3 and could be used to enhance biomass productivity in O3 polluted regions.


Assuntos
Ozônio/farmacologia , Fotossíntese/efeitos dos fármacos , Sorghum/metabolismo , Clorofila/metabolismo , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Transpiração Vegetal/efeitos dos fármacos , Sorghum/efeitos dos fármacos , Sorghum/crescimento & desenvolvimento , Sorghum/fisiologia
11.
Plant J ; 105(4): 1053-1071, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33211340

RESUMO

Stems of bioenergy sorghum (Sorghum bicolor L. Moench.), a drought-tolerant C4 grass, contain up to 50 nodes and internodes of varying length that span 4-5 m and account for approximately 84% of harvested biomass. Stem internode growth impacts plant height and biomass accumulation and is regulated by brassinosteroid signaling, auxin transport, and gibberellin biosynthesis. In addition, an AGCVIII kinase (Dw2) regulates sorghum stem internode growth, but the underlying mechanism and signaling network are unknown. Here we provide evidence that mutation of Dw2 reduces cell proliferation in internode intercalary meristems, inhibits endocytosis, and alters the distribution of heteroxylan and mixed linkage glucan in cell walls. Phosphoproteomic analysis showed that Dw2 signaling influences the phosphorylation of proteins involved in lipid signaling (PLDδ), endomembrane trafficking, hormone, light, and receptor signaling, and photosynthesis. Together, our results show that Dw2 modulates endomembrane function and cell division during sorghum internode growth, providing insight into the regulation of monocot stem development.


Assuntos
Proliferação de Células/fisiologia , Parede Celular/metabolismo , Proteínas de Plantas/metabolismo , Caules de Planta/metabolismo , Sorghum/fisiologia , Xilanos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Hibridização In Situ , Microscopia Confocal , Fosforilação , Proteínas de Plantas/fisiologia , Caules de Planta/crescimento & desenvolvimento , Caules de Planta/fisiologia , Feixe Vascular de Plantas/metabolismo , Feixe Vascular de Plantas/fisiologia , Feixe Vascular de Plantas/ultraestrutura , Proteômica , Sorghum/enzimologia , Sorghum/crescimento & desenvolvimento , Sorghum/metabolismo
12.
J Agric Food Chem ; 68(50): 14781-14789, 2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33274637

RESUMO

With the perpetuation of soil salinization, it is imperative to improve the salt and alkaline tolerance of crops. Sorghum bicolor, a C4 crop, is often grown in semiarid areas due to its high tolerance of various abiotic stresses. Whether to improve the resistance of the sorghum itself or that of other crops, it is necessary to understand the response of sorghum under saline-alkali stress. An integrative analysis of the metabolome and transcriptome of sorghum under normal conditions and treatments of moderate and severe saline-alkali stress was performed. Among the different accumulated metabolites (DAMs) and differentially expressed genes (DEGs), flavonoid-related DAMs and DEGs were clearly changed. The level of flavonoids was increased under saline-alkali stress, and the change in flavonoids was dynamic as to whether total flavonoids or most flavonoid components accumulated more under moderate saline-alkali stress compared to severe stress. Some flavonoid metabolites were significantly correlated with the expression of flavonoid biosynthesis genes. MYB transcription factors may also contribute to the regulation of flavonoids levels. These findings present the dynamic changes and possible molecular mechanisms of flavonoids under different saline-alkali stresses and provide a foundation for future research and crop improvement.


Assuntos
Álcalis/metabolismo , Flavonoides/biossíntese , Proteínas de Plantas/genética , Cloreto de Sódio/metabolismo , Sorghum/fisiologia , Regulação da Expressão Gênica de Plantas , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Sorghum/genética , Estresse Fisiológico , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcriptoma
13.
Int J Mol Sci ; 21(24)2020 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-33352693

RESUMO

Drought is the largest stress affecting agricultural crops, resulting in substantial reductions in yield. Plant adaptation to water stress is a complex trait involving changes in hormone signaling, physiology, and morphology. Sorghum (Sorghum bicolor (L.) Moench) is a C4 cereal grass; it is an agricultural staple, and it is particularly drought-tolerant. To better understand drought adaptation strategies, we compared the cytosolic- and organelle-enriched protein profiles of leaves from two Sorghum bicolor genotypes, RTx430 and BTx642, with differing preflowering drought tolerances after 8 weeks of growth under water limitation in the field. In agreement with previous findings, we observed significant drought-induced changes in the abundance of multiple heat shock proteins and dehydrins in both genotypes. Interestingly, our data suggest a larger genotype-specific drought response in protein profiles of organelles, while cytosolic responses are largely similar between genotypes. Organelle-enriched proteins whose abundance significantly changed exclusively in the preflowering drought-tolerant genotype RTx430 upon drought stress suggest multiple mechanisms of drought tolerance. These include an RTx430-specific change in proteins associated with ABA metabolism and signal transduction, Rubisco activation, reactive oxygen species scavenging, flowering time regulation, and epicuticular wax production. We discuss the current understanding of these processes in relation to drought tolerance and their potential implications.


Assuntos
Secas , Flores/fisiologia , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Sorghum/fisiologia , Estresse Fisiológico , Frações Subcelulares/metabolismo , Flores/genética , Regulação da Expressão Gênica de Plantas , Genótipo , Proteoma/análise , Sorghum/genética
14.
PLoS One ; 15(12): e0243824, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33370318

RESUMO

The use of bio-fertilizers in agro-ecosystems is considered to have the potential to improve plant growth in extreme environments featuring water shortages. However, while arbuscular mycorrhizal fungi (AMF) and bacteria bio-fertilizers have been used in other plants to enhance stress tolerance, little is known about their symbiotic effect on sorghum (Sorghum bicolor L.) growth under drought stress conditions. Therefore the aim of this study was to investigate the inoculation of sorghum with Nitroxin and Glomus mosseae and their interaction effects on the agro-physiological characteristics and grain yield of sorghum under drought stress conditions. Nitroxin is a bio-fertilizer that consists of a mixture of Azospirillum and Azotobacter bacteria. The results showed that co-inoculation of sorghum seeds with Nitroxin and AMF improved the chlorophyll (a, b and total) content, soluble proteins, water use efficiency) WUE(, relative water content (RWC), nitrogen (N) content in the plant, AMF spore density, proline content, grain yield, panicle length, the number of panicles per plant, grain number per panicle, 1000-grain weight and decreased the electrolyte leakage and water saturation deficit (WSD) in drought stress and non-stress conditions. Under drought stress conditions, there was a 27% increase in grain yield under the synergistic effects of bacteria and fungi compared to the non-application of these microorganisms. The results of this experiment show that Nitroxin and AMF bio-fertilizers can mitigate the negative effects of stress on plants in drought stress conditions by increasing the amount of photosynthetic pigments, soluble proteins and osmotic regulation and decreasing electrolyte leakage. We found that the combination of bacteria and AMF for sorghum growth and yield increment is a promising method to cope with the stress caused by drought.


Assuntos
Secas , Fertilizantes , Micorrizas/fisiologia , Sementes/crescimento & desenvolvimento , Sorghum/microbiologia , Sorghum/fisiologia , Estresse Fisiológico , Irrigação Agrícola , Análise de Variância , Clorofila/metabolismo , Eletrólitos/metabolismo , Conceitos Meteorológicos , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Prolina/metabolismo , Característica Quantitativa Herdável , Estações do Ano , Solubilidade , Sorghum/crescimento & desenvolvimento , Esporos Fúngicos/fisiologia , Água/metabolismo
15.
Plant Physiol ; 184(4): 1927-1940, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33093232

RESUMO

A "smart canopy" ideotype has been proposed with leaves being upright at the top and more horizontal toward the bottom of the plant to maximize light interception and conversion efficiencies, and thus increasing yield. The genetic control of leaf angle has, to date, been studied on one or two leaves, or data have been merged from multiple leaves to generate average values. This approach has limited our understanding of the diversity of leaf angles across layers and their genetic control. Genome-wide association studies and quantitative trait loci mapping studies in sorghum (Sorghum bicolor) were performed using layer-specific angle data collected manually and via high-throughput phenotyping strategies. The observed distribution of angles in indoor and field settings is opposite to the ideotype. Several genomic regions were associated with leaf angle within layers or across the canopy. The expression of the brassinosteroid-related transcription factor BZR1/BES1 and the auxin-transporter Dwarf3 were found to be highly correlated with the distribution of angles at different layers. The application of a brassinosteroid biosynthesis inhibitor could not revert the undesirable overall angle distribution. These discoveries demonstrate that the exploitation of layer-specific quantitative trait loci/genes will be instrumental to reversing the natural angle distribution in sorghum according to the "smart canopy" ideotype.


Assuntos
Luz , Fotossíntese/fisiologia , Folhas de Planta/anatomia & histologia , Folhas de Planta/genética , Sorghum/anatomia & histologia , Sorghum/genética , Sorghum/fisiologia , Brassinosteroides/metabolismo , Grão Comestível/anatomia & histologia , Grão Comestível/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Estudo de Associação Genômica Ampla , Genótipo , Fatores de Transcrição/genética
16.
Plant Cell ; 32(11): 3500-3518, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32873633

RESUMO

Sorghum (Sorghum bicolor) and its relatives in the grass tribe Andropogoneae bear their flowers in pairs of spikelets in which one spikelet (seed-bearing or sessile spikelet [SS]) of the pair produces a seed and the other is sterile or male (staminate). This division of function does not occur in other major cereals such as wheat (Triticum aestivum) or rice (Oryza sativa). Additionally, one bract of the SS spikelet often produces a long extension, the awn, that is in the same position as, but independently derived from, that of wheat and rice. The function of the sterile spikelet is unknown and that of the awn has not been tested in Andropogoneae. We used radioactive and stable isotopes of carbon, RNA sequencing of metabolically important enzymes, and immunolocalization of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) to show that the sterile spikelet assimilates carbon, which is translocated to the largely heterotrophic SS. The awn shows no evidence of photosynthesis. These results apply to distantly related species of Andropogoneae. Removal of sterile spikelets in sorghum significantly decreases seed weight (yield) by ∼9%. Thus, the sterile spikelet, but not the awn, affects yield in the cultivated species and fitness in the wild species.


Assuntos
Proteínas de Plantas/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Sorghum/fisiologia , Andropogon/fisiologia , Carbono/metabolismo , Radioisótopos de Carbono , Regulação da Expressão Gênica de Plantas , Marcação por Isótopo , Malatos/metabolismo , Células do Mesofilo , Fotossíntese/genética , Folhas de Planta/genética , Proteínas de Plantas/genética , Poaceae/crescimento & desenvolvimento , Poaceae/fisiologia , Análise de Sequência de RNA , Sorghum/crescimento & desenvolvimento
17.
Genes (Basel) ; 11(9)2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32883037

RESUMO

This study was conducted to dissect the genetic basis and to explore the candidate genes underlying one of the important genomic regions on an SBI-10 long arm (L), governing the complex stay-green trait contributing to post-flowering drought-tolerance in sorghum. A fine-mapping population was developed from an introgression line cross-RSG04008-6 (stay-green) × J2614-11 (moderately senescent). The fine-mapping population with 1894 F2 was genotyped with eight SSRs and a set of 152 recombinants was identified, advanced to the F4 generation, field evaluated with three replications over 2 seasons, and genotyped with the GBS approach. A high-resolution linkage map was developed for SBI-10L using 260 genotyping by sequencing-Single Nucleotide Polymorphism (GBS-SNPs). Using the best linear unpredicted means (BLUPs) of the percent green leaf area (%GL) traits and the GBS-based SNPs, we identified seven quantitative trait loci (QTL) clusters and single gene, mostly involved in drought-tolerance, for each QTL cluster, viz., AP2/ERF transcription factor family (Sobic.010G202700), NBS-LRR protein (Sobic.010G205600), ankyrin-repeat protein (Sobic.010G205800), senescence-associated protein (Sobic.010G270300), WD40 (Sobic.010G205900), CPK1 adapter protein (Sobic.010G264400), LEA2 protein (Sobic.010G259200) and an expressed protein (Sobic.010G201100). The target genomic region was thus delimited from 15 Mb to 8 genes co-localized with QTL clusters, and validated using quantitative real-time (qRT)-PCR.


Assuntos
Senescência Celular , Mapeamento Cromossômico/métodos , Ligação Genética , Proteínas de Plantas/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Sorghum/genética , Folhas de Planta/genética , Folhas de Planta/fisiologia , Sorghum/fisiologia
18.
Plant Physiol Biochem ; 154: 723-734, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32763797

RESUMO

This study investigated the proteome modulation and physiological responses of Sorghum bicolor plants grown in nutrient solutions containing nitrate (NO3-) or ammonium (NH4+) at 5.0 mM, and subjected to salinity with 75 mM NaCl for ten days. Salinity promoted significant reductions in leaf area, root and shoot dry mass of sorghum plants, regardless of nitrogen source; however, higher growth was observed in ammonium-grown plants. The better performance of ammonium-fed stressed plants was associated with low hydrogen peroxide accumulation, and improved CO2 assimilation and K+/Na+ homeostasis under salinity. Proteomic study revealed a nitrogen source-induced differential modulation in proteins related to photosynthesis/carbon metabolism, energy metabolism, response to stress and other cellular processes. Nitrate-fed plants induced thylakoidal electron transport chain proteins and structural and carbon assimilation enzymes, but these mechanisms seemed to be insufficient to mitigate salt damage in photosynthetic performance. In contrast, the greater tolerance to salinity of ammonium-grown plants may have arisen from: i.) de novo synthesis or upregulation of enzymes from photosynthetic/carbon metabolism, which resulted in better CO2 assimilation rates under NaCl-stress; ii.) activation of proteins involved in energy metabolism which made available energy for salt responses, most likely by proton pumps and Na+/H+ antiporters; and iii.) reprogramming of proteins involved in response to stress and other metabolic processes, constituting intricate pathways of salt responses. Overall, our findings not only provide new insights of molecular basis of salt tolerance in sorghum plants induced by ammonium nutrition, but also give new perspectives to develop biotechnological strategies to generate more salt-tolerant crops.


Assuntos
Compostos de Amônio , Tolerância ao Sal , Sorghum/fisiologia , Folhas de Planta , Proteômica , Salinidade
19.
Planta ; 252(1): 14, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-32621008

RESUMO

MAIN CONCLUSION: The findings of this study suggest that known resistant sorghum genotypes compensate for feeding pressure of sugarcane aphid by maintaining/increasing photosynthetic capacity and/or have higher chlorophyll content than susceptible genotypes. Knowledge of the physiological response of sorghum, (Sorghum bicolor (L.) Moench), to sugarcane aphid (SCA), Melanaphis sacchari (Zehnter) feeding will provide baseline information on defense responses and resistance mechanisms. This study documented the impact of SCA feeding on seven sorghum genotypes by measuring chlorophyll content, photosynthetic rate, stomatal conductance, and carbon assimilation for a 14-d post-infestation evaluation. Carbon assimilation (A/Ci) curves were recorded at 3, 6, 9, and 15 d after aphid infestation to describe the pattern of physiological response of resistant and susceptible sorghums over time. Chlorophyll loss from resistant genotypes was significantly lower (≤ 10% loss) than from susceptible cultivars. Most resistant genotypes compensated for aphid feeding by either increasing or maintaining photosynthetic rate and stomatal conductance. Carbon assimilation curves over time showed that infested resistant plants had delayed photosynthetic decreases, whereas susceptible plants rapidly lost photosynthetic capacity. This research also investigated the influence of aphid density (0, 50, 100, and 200 nymphs/plant) on the photosynthetic rates of 28-d-old resistant and susceptible sorghums measured at 72-h post-infestation. Although there were no visual symptoms in susceptible sorghums, photosynthetic rates were impaired when infested with ≥ 100 SCA. In contrast, resistant plants were able to compensate for SCA feeding. Differences in the physiological responses of susceptible versus resistant sorghums indicate that resistant sorghum plants can tolerate some physiological impacts of SCA feeding and maintain photosynthetic integrity.


Assuntos
Afídeos/fisiologia , Sorghum/fisiologia , Animais , Afídeos/patogenicidade , Dióxido de Carbono/metabolismo , Clorofila/metabolismo , Genótipo , Fotossíntese , Densidade Demográfica , Sorghum/genética
20.
PLoS One ; 15(7): e0235896, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730265

RESUMO

Mature sorghum herbage is known to contain several water-soluble secondary metabolites (allelochemicals). In this study, we investigated quantitative trait loci (QTLs) associated with allelochemical characteristics in sorghum using linkage mapping and linkage disequilibrium (LD)-based association mapping. A sorghum diversity research set (SDRS) of 107 accessions was used in LD mapping whereas, F2:3 lines derived from a cross between Japanese and African landraces were used in linkage mapping. The QTLs were further confirmed by positional (targeted) association mapping with Q+K model. The inhibitory effect of water-soluble extracts (WSE) was tested on germination and root length of lettuce seedlings in four concentrations (25%, 50%, 75% and 100%). A Significant range of variations was observed among genotypes in both types of mapping populations (P < 0.05). A total of 181 simple sequence repeats (SSRs) derived from antecedently reported map have been used for genotyping of SDRS. A genetic linkage map of 151 sorghum SSR markers was also developed on 134 F2 individuals. The total map length was 1359.3 cM, with an average distance of 8.2 cM between adjacent markers. LD mapping identified three QTLs for inhibition effect on germination and seven QTLs for root length of lettuce seedlings. Whereas, a total of six QTLs for inhibition of germination and ten QTLs for root length were detected in linkage mapping approach. The percent phenotypic variation explained by individual QTL ranged from 6.9% to 27.3% in SDRS and 9.9% to 35.6% in F2:3 lines. Regional association analysis identified four QTLs, three of them are common in other methods too. No QTL was identified in the region where major gene for sorgoleone (SOR1) has been cloned previously on chromosome 5.


Assuntos
Locos de Características Quantitativas , Sorghum/genética , Ligação Genética , Germinação/genética , Repetições de Microssatélites , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plântula/genética , Plântula/crescimento & desenvolvimento , Sorghum/crescimento & desenvolvimento , Sorghum/fisiologia
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