Sorghum Leaf Research Articles

Molecular, chemical, and physiological analyses of sorghum leaf wax under post-flowering drought stress

Wax accumulation on the sorghum surface plays an important role in drought tolerance by preventing non-stomatal water loss. Thereby, the effect of post-flowering drought stress (PFDS) on the epicuticular wax (EW) amount, relative water content (RWC), chlorophyll, and grain yield in sorghum drought contrasting genotypes were investigated. The experiment was conducted as a split-plot based on randomized complete block design (RCBD) with two water treatments (normal watering and water holding after 50% flowering stage), and three genotypes (Kimia and KGS23 as drought-tolerant and Sepideh as drought-susceptible). Scanning electron microscopy and GC-MS analyses were used to determine the wax crystals density and its compositions, respectively. In addition, based on literature reviews and publicly available datasets, six wax biosynthesis drought stress-responsive genes were chosen for expression analysis. The results showed that the amounts of EW and wax crystals density were increased in Kimia and Sepideh genotypes and no changed in KGS23 genotype under drought stress. Chemical compositions of wax were classified into six major groups including alkanes, fatty acids, aldehydes, esters, alcohols, and cyclic compounds. Alkanes increment in drought-tolerant genotypes led to make an effective barrier against the drought stress to control water losses. In addition, the drought-tolerant genotypes had higher levels of RWC compared to the drought-susceptible ones, resulted in higher yield produced under drought condition. According to the results, SbWINL1, FATB, and CER1 genes play important roles in drought-induced wax biosynthesis. The results of the present study revealed a comprehensive view of the wax and its compositions and some involved genes in sorghum under drought stress.

Development and Evaluation of Nutraceutical products from Soybean, Sorghum and Basil leaf using Response Surface Methodology

A central composite orthogonal experimental design (CCOD) was used to develop a nutraceutical product from soy protein isolate, sorghum pyrodextrin and basil instant soluble powder using their levels incorporation as the independent factors while functional, and antinutritional parameters served as the responses. The haematological and biochemical parameters of albino wistar rat fed with the preferred nutraceutical product were determined. Sensory profiling by 30 panelists using a 9-point hedonic scale was conducted. The response surface analysis of the dependent variables of the products revealed both quadratic and linear fitted effects (P<0.05).The developed nutraceutical product had water absorption capacity, 1.69g/g, oil absorption capacity, 0.78g/cm3 bulk density, 6.82 pH, 1.40mg/g trypsin inhibitor, 0.73mg/100g phytate, 0.54mg/100g tannin, and 2.15HU/mg haemagglutinins. The nutraceutical product boosted the homopeitic activities, reduced the fasting blood glucose and cholesterol of the experimental rats, while biochemical analysis indicated no toxicological implication. A regression graph of the observed and predicted physicochemical properties of the product showed a highly fitted model of R2 = 0.999. Consumer acceptability tests showed that the developed nutraceutical product was accepted by the panelists.

Effect of Sorghum and Indigofera Leaf Flour on Egg Quality, Daily Protein Intake, Phosphorus Availability and Total Colonies of Bacillus sp in Small Intestines of Laying Hens

Effect of Sorghum and Indigofera Leaf Flour on Egg Quality, Daily Protein Intake, Phosphorus Availability and Total Colonies of Bacillus sp in Small Intestines of Laying Hens

Evaluation of biocides and phyto chemicals for the management of thrips and groundnut bud necrosis virus (GBNV) in groundnut

Field studies were conducted to evaluate the biocides and phyto chemicals in farmers’ field for the management of groundnut thrips and Groundnut bud necrosis virus (GBNV) in groundnut. Three rounds of sprays of biocides and phyto chemicals were given along with untreated check. Sorghum leaf extract (10%) + quinalphos 25 EC (0.05%) and coconut leaf extract (10%) + quinalphos 25 EC (0.05%) showed the maximum reduction on thrips population and also suppressed the GBNV incidence and increased pod yield when compared to the control in both the trials.

Effects of biological insecticides on the sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), in sorghum

Melanaphis sacchari (Zehntner) is a major pest of sorghum, Sorghum bicolor (L.) Moench, in the United States and neighboring Caribbean countries including Haiti. Laboratory, greenhouse, and field experiments were conducted to determine the effects of biological insecticides on M. sacchari infesting sorghum. Azadirachtin, pyrethrins, Beauveria bassiana strain GHA, Isaria fumosorosea Apopka strain 97, Chromobacterium subtsugae strain PRAA4-1T, Burkholderia spp. strain A396, and vetiver oil were compared to a conventional insecticide, flupyradifurone. In the laboratory, sorghum leaf discs were sprayed with treatment solutions and subsequently infested with M. sacchari nymphs. In the greenhouse, potted sorghum plants were sprayed with treatment solutions before or after infestation with M. sacchari nymphs. In the field, plots exposed to natural M. sacchari infestations were sprayed with treatment solutions. All insecticide treatments except I. fumosorosea and Burkholderia spp. were associated with 58–100% aphid mortality after 72 h in the laboratory, which was greater than the 20% mortality observed in the non-treated control. In the greenhouse, azadirachtin and pyrethrins were the biological insecticides associated with the lowest aphid infestation levels 7 days after treatment. Flupyradifurone was associated with the greatest mortality in the laboratory and the lowest infestation levels in the greenhouse. In the field, decreases in aphid infestation levels relative to the non-treated control were not observed although flupyradifurone was consistently associated with the lowest infestations. Our results suggest that biological insecticides including azadirachtin, pyrethrins, and B. bassiana could potentially control M. sacchari infestations in sorghum if applied under favorable environmental conditions.

Capacity of ethanol adjunct-treated interface of ionic liquid aqueous two phase system in simultaneous extraction and purification of sorghum leaf sheath polysaccharides

ABSTRACT Employing response surface methodology, partially purified polysaccharides from Sorghum bicolor L. leaf sheath were extracted using synergized ethanol adjunct-treated ionic liquid aqueous two phase system (1-octyl-3-methylimidazolium chloride, [C8mim]Cl and K2CO3) and dual frequency ultrasound-assisted extraction. Under ultrasound conditions of 35 °C, 20&60 KHz, 25 mins an experimental yield of 16% PPS was achieved. Dual frequency ultrasound-assisted dialysis effectively reduced salt content of extracted PPS solution in a liquid membrane. The polysaccharides collected after dialysis maintained primary structures. The introduction of ethanol in the ionic liquid aqueous two phase system therefore ensured an excellent simultaneous extraction and partial purification.

Quantitative detection of Exserohilum turcicum in northern leaf blight diseased sorghum and maize leaves

Exserohilum turcicum is the causal agent of northern leaf blight (NLB) disease in sorghum and maize. Early detection of this economically important pathogen is essential for effective disease management to limit yield losses. Here we present a real-time quantitative PCR (qPCR) assay specific for E. turcicum detection and biomass quantification in sorghum and maize. In planta fungal quantification was achieved through amplification of a cytochrome P450 oxidoreductase (cpr1) gene fragment and subsequent normalisation to the host glutathione S-transferase III gene (gst3). The assay could specifically detect E. turcicum in sorghum and maize, but the cpr1 gene fragment was not amplified in non-target fungal pathogens. Application of the assay with NLB diseased sorghum and maize leaf material revealed a significant increase in E. turcicum DNA in leaves with lesion symptoms when compared to leaves with early stage chlorotic fleck symptoms in both hosts. Furthermore, E. turcicum was detected at levels as low as 1 pg in infected sorghum and maize leaves. The assay enables rapid detection and quantification of E. turcicum in sorghum and maize and has useful applications in crop breeding programmes and disease management where cultivar selection and early detection of the pathogen are essential to limit disease spread.

SbWRKY30 enhances the drought tolerance of plants and regulates a drought stress-responsive gene, SbRD19, in sorghum

WRKY transcription factors have been suggested to play important roles in response and adaptation to drought stress. However, how sorghum WRKY transcription factors function in drought stress is still unclear. Here, we identify a WRKY transcription factor of sorghum, SbWRKY30, which is induced significantly by drought stress. SbWRKY30 is mainly expressed in sorghum taproot and leaf. SbWRKY30 has transcriptional activation activity and functions in the nucleus. Heterologous expression of SbWRKY30 confers tolerance to drought stress in Arabidopsis (Arabidopsis thaliana) and rice by affecting root architecture. In addition, SbWRKY30 transgenic Arabidopsis and rice plants have higher proline contents and SOD, POD, and CAT activities but lower MDA contents than wild-type plants after drought stress. As a homologous gene of the drought stress-responsive gene RD19 of Arabidopsis, SbRD19 overexpression in Arabidopsis improved the drought tolerance of plants relative to wild-type plants. Further analysis demonstrated that SbWRKY30 could induce SbRD19 expression through binding to the W-box element in the promoter of SbRD19. These results suggest that SbWRKY30 functions as a positive regulator in response to drought stress. Therefore, SbWRKY30 may serve as a promising candidate gene for molecular breeding to generate drought-tolerant crops.

Conserved defense responses between maize and sorghum to Exserohilum turcicum

BackgroundExserohilum turcicum is an important pathogen of both sorghum and maize, causing sorghum leaf blight and northern corn leaf blight. Because the same pathogen can infect and cause major losses for two of the most important grain crops, it is an ideal pathosystem to study plant-pathogen evolution and investigate shared resistance mechanisms between the two plant species. To identify sorghum genes involved in the E. turcicum response, we conducted a genome-wide association study (GWAS).ResultsUsing the sorghum conversion panel evaluated across three environments, we identified a total of 216 significant markers. Based on physical linkage with the significant markers, we detected a total of 113 unique candidate genes, some with known roles in plant defense. Also, we compared maize genes known to play a role in resistance to E. turcicum with the association mapping results and found evidence of genes conferring resistance in both crops, providing evidence of shared resistance between maize and sorghum.ConclusionsUsing a genetics approach, we identified shared genetic regions conferring resistance to E. turcicum in both maize and sorghum. We identified several promising candidate genes for resistance to leaf blight in sorghum, including genes related to R-gene mediated resistance. We present significant advancements in the understanding of host resistance to E. turcicum, which is crucial to reduce losses due to this important pathogen.

Rapid and efficient method of genomic dna extraction from sweet sorghum [&lt;em&gt;Sorghum bicolor&lt;/em&gt; (L.)] using leaf tissue

Extraction of genomic DNA from plant leaf tissue is a basic requirement for molecular biology experiment as well as in plant breeding for crop improvement. The purity of DNA is affected by varying level of polyphenols, polysaccharides and secondary metabolites with are associated with DNA at the time of extraction. A variety of DNA extraction methods and kits are available, however they are costly, low yield and time consuming. Here, we describe a simple and efficient method of DNA extraction from sorghum leaf. The present study is based on conventional cetyl trimethyl ammonium bromide (CTAB) method with four major modifications to isolate genomic DNA from seven different accessions of sorghum and the yield of DNA was varied from1550.2 ngµl-1 to 1910.5ngµl-1 in 100 µl final volume of TE buffer. The purity of DNA sample was found to be varied from 1.53 to 2.16 based on the absorbance at A260 and A280 ratio. This method is very simple as it not requires liquid nitrogen or magnetic beads to grind the leaf sample which is mostly unavailable to some undergraduate laboratories.

Transcriptomic analysis of a Sorghum bicolor landrace identifies a role for beta-alanine betaine biosynthesis in drought tolerance

Sorghum is indigenous to Africa and a remarkably drought tolerant cereal crop. In this study, the genetic response mechanisms involved in sorghum's tolerance to progressive water deficit and re-watering were investigated in a South African landrace (designated LR6), using cDNA microarrays comprising 35,899 transcript probes. Significant differential expression of 902 transcripts, including 128 transcripts with currently unknown functions, was altered in response to progressive water stress and re-watering. The modulated sorghum genes had homology to proteins involved in growth, regulation, and protection. Gene Ontology (GO) analysis identified significant enrichment of 26 genes involved in the ‘response to abiotic stimulus’ GO category during severe stress. The expression of two genes associated with beta(β)-alanine betaine biosynthesis was validated with quantitative RT-PCR. Importantly, the detection of β-alanine betaine in sorghum leaf extracts using NMR spectroscopy, and the significant increase in relative abundance during severe stress supports the microarray and qRT-PCR findings, thereby highlighting a role for β-alanine betaine biosynthesis in drought tolerance of sorghum. In future, crop improvement initiatives that consider metabolic engineering of the β-alanine betaine biosynthesis pathway should be explored.

Anionic Phospholipids Induce Conformational Changes in Phosphoenolpyruvate Carboxylase to Increase Sensitivity to Cathepsin Proteases.

Phosphoenolpyruvate carboxylase (PEPC) is a cytosolic, homotetrameric enzyme that serves a variety of functions in plants, acting as the primary form of CO2 fixation in the C4 photosynthesis pathway (C4-PEPC). In a previous work we have shown that C4-PEPC bind anionic phospholipids, resulting in PEPC inactivation. Also, we showed that PEPC can associate with membranes and to be partially proteolyzed. However, the mechanism controlling this remains unknown. Using semi purified-PEPC from sorghum leaf and a panel of PEPC-specific antibodies, we analyzed the conformational changes in PEPC induced by anionic phospholipids to cause the inactivation of the enzyme. Conformational changes observed involved the exposure of the C-terminus of PEPC from the native, active enzyme conformation. Investigation of the protease activity associated with PEPC demonstrated that cysteine proteases co-purify with the enzyme, with protease-specific substrates revealing cathepsin B and L as the major protease species present. The anionic phospholipid-induced C-terminal exposed conformation of PEPC appeared highly sensitive to the identified cathepsin protease activity and showed initial proteolysis of the enzyme beginning at the N-terminus. Taken together, these data provide the first evidence that anionic phospholipids promote not only the inactivation of the PEPC enzyme, but also its proteolysis.

Optimized activated charcoal detoxification of acid-pretreated lignocellulosic substrate and assessment for bioethanol production

This study optimized an activated charcoal (AC) detoxification method for the reduction of three different fermentation inhibitor compounds, while minimising the reducing sugar loss from acid-pretreated sorghum leaf (SL) wastes. Process optimization demonstrated a 98%, 88% and 37% removal efficiency for furfural, 5-hydroxymethylfurfural (HMF) and acetic acid respectively, with a 7% reducing sugar loss. Subsequently, the logistic and modified Gompertz models were used to comparatively evaluate the kinetics of Saccharomyces cerevisiae growth and ethanol production using the non-detoxified (NDF) and optimized detoxified (ODF) substrate. Yeast cell growth and bioethanol kinetic coefficients revealed that the ODF process was more effective than the NDF system. The experimental data generated from this study revealed that a suitable, cost-effective AC detoxification enhanced cell growth and bioethanol production efficiency. These findings pave the way for biomass pretreatment, detoxification and bioethanol process development using lignocellulosic wastes.

High-throughput quantitative analysis of phytohormones in sorghum leaf and root tissue by ultra-performance liquid chromatography-mass spectrometry.

Plant development, growth, and adaptation to stress are regulated by phytohormones, which can influence physiology even at low concentrations. Phytohormones are chemically grouped according to both structure and function as auxins, cytokinins, abscisic acid, jasmonates, salicylates, gibberellins, and brassinosteroids, among others. This chemical diversity and requirement for highly sensitive detection in complex matrices create unique challenges for comprehensive phytohormone analysis. Here, we present a robust and efficient quantitative UPLC-MS/MS assay for 17 phytohormones, including jasmonates, salicylates, abscisic acid, gibberellins, cytokinins, and auxins. Using this assay, 12 phytohormones were detected and quantified in sorghum plant tissue without the need for solid phase extraction (SPE) or liquid-liquid extraction. Variation of phytohormone profiles was explored in both root and leaf tissues between three genotypes, harvested at two different developmental time points. The results highlight the importance of tissue type, sampling time, and genetic factors when designing experiments that involve phytohormone analysis of sorghum. This research lays the groundwork for future studies, which can combine phytohormone profiling with other datasets such as transcriptome, soil microbiome, genome, and metabolome data, to provide important functional information about adaptation to stress and other environmental variables.

Pathways of soil organic matter formation from above and belowground inputs in a Sorghum bicolor bioenergy crop

AbstractWhen aboveground materials are harvested for fuel production, such as with Sorghum bicolor, the sustainability of annual bioenergy feedstocks is influenced by the ability of root inputs to contribute to the formation and persistence of soil organic matter (SOM), and to soil fertility through nutrient recycling. Using 13C and 15N labeling, we traced sorghum root and leaf litter‐derived C and N for 19 months in the field as they were mineralized or formed SOM. Our in situ litter incubation experiment confirms that sorghum roots and leaves significantly differ in their inherent chemical recalcitrance. This resulted in different contributions to C and N storage and recycling. Overall root residues had higher biochemical recalcitrance which led to more C retention in soil (27%) than leaf residues (19%). However, sorghum root residues resulted in higher particulate organic matter (POM) and lower mineral associated organic matter (MAOM), deemed to be the most persistent fraction in soil, than leaf residues. Additionally, the overall higher root‐derived C retention in soil led to higher N retention, reducing the immediate recycling of fertility from root as compared to leaf decomposition. Our study, conducted in a highly aggregated clay‐loam soil, emphasized the important role of aggregates in new SOM formation, particularly the efficient formation of MAOM in microaggregate structures occluded within macroaggregates. Given the known role of roots in promoting aggregation, efficient formation of MAOM within aggregates can be a major mechanism to increase persistent SOM storage belowground when aboveground residues are removed. We conclude that promoting root inputs in S. bicolor bioenergy production systems through plant breeding efforts may be an effective means to counterbalance the aboveground residue removal. However, management strategies need to consider the quantity of inputs involved and may need to support SOM storage and fertility with additional organic matter additions.

THE MAIN WAYS OF INFECTION OF GRAIN SORGHUM BY BURKHOLDERIA ANDROPOGONIS (BURKHOLDERIACEAE, BURKHOLDERIALES) IN THE FOREST-STEPPE OF THE MIDDLE VOLGA REGION

Bacterial leaf stripe, caused by Burkholderia andropogonis, is one of the main sorghum diseases in the forest-steppe of the Middle Volga region. The purpose of the research was to examine the main ways of infection of sorghum by Burkholderia andropogonis. The studies were carried out on experimental fields of the Volga region Scientific Research Institute of Selection and Seed-growing and in the laboratories of Plant Protection and Microbiology of the Samara State Agricultural Academy in 2010-2015. The severity of sorghum leaf stripe in the stage of physiological maturity was 9-60%, with a maximum in high-drought (2010), minimum in wet and cool (2011) years. Losses of grain sorghum yield from B. andropogonis were on average up to 30 %. The main overwintering and primary inoculum sources reported are infested seeds. Up to 97-100 % of the sorghum seeds were infected with B. andropogonis. After sowing infected seeds, bacteria spread through the vascular system in seedlings and developing plants, penetrating into emerging and ripening seeds. The main indirect vector of bacterial leaf stripe is the flea beetle Phyllotreta vittula feeding on sorghum leaves. In the first half of July, adults of the new generation of P. vittula facilitate the penetration of the pathogen from B. andropogonis exudate into the tissues of sorghum through wounds that feeding beetles form on the upper surface of young leaves. The role of flea beetles P. vittula in the spread of the bacteria B andropogonis in crops of sorghum recorded for the first time.

Application of apigeninidin-rich red sorghum biocolorant in a fermented food improves product quality.

BACKGROUNDThe ‘clean label’ trend is pushing the food industry to replace synthetic colorants with plant‐based colorants. However, technological efficacy and undesirable side effects restrict the use of plant‐based colorants in industrial applications. This research studied the production of fermented maize dough coloured by apigeninidin‐rich red sorghum biocolorant, as practised for centuries in West Africa, as a model to assess the impact of the biocolorant on nutritional and sensorial quality of foods.RESULTSA 3‐day fermentation of a dyed maize dough (containing 327 µg g−1 dry matter of apigeninidin) by Pichia kudriavzevii and Lactobacillus fermentum led to a degradation of 69% of the apigeninidin content, causing a clearly visible colour difference (ΔE*00 17.4). The antioxidant activity of fermented dyed dough (DD) increased by 51% compared to fermented non‐dyed dough (NDD). However, the phytate dephosphorylation and volatile organic compound concentrations were lower in DD than in NDD. This suggests a lower mineral solubility and change in the sensory quality of fermented DD.CONCLUSIONApigeninidin extract from sorghum leaf sheaths proved to be a bioactive red biocolorant with potential in fermented foods. The formation of new antioxidant compounds needs further investigation, as does the impact on the development of volatile compounds. © 2018 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Sewage sludge amendment improved soil properties and sweet sorghum yield and quality in a newly reclaimed mudflat land

Growing bioenergy crop on marginal lands has the potential to minimize land use conflicts and meet global energy demand. The newly reclaimed mudflats through sewage sludge amendment can be used as a potential marginal land for bioenergy production. This paper was one of first studies to investigate the persistent impact of sewage sludge application at the rates of 0, 25, 50, 125, and 250 t ha−1 on selected soil physicochemical properties, yields and quality of sweet sorghum (Sorghum bicolor L.) cultivated in newly reclaimed mudflat saline-alkaline soil. The results showed that sewage sludge amendment (SSA) improved physicochemical properties by decreasing bulk density, electric conductivity, pH, and increasing soil organic carbon, >0.25 mm water-stable aggregate fraction, cation exchange capacity, nitrogen, and phosphorus contents in mudflat soil. Consequently, the sweet sorghum biomass and gross energy content were significantly elevated by SSA. The sweet sorghum achieved the maximum biomasses of 4.73 and 6.62 t ha−1 at 250 t ha−1 SSA rate in 2016 and 2017, respectively. The gross energy content of sweet sorghum significantly increased with the SSA rates, although SSA slightly reduced the calorific values in stem and leaf of sweet sorghum. The maximum gross energy contents of sweet sorghum were 79.62 and 104.47 GJ ha−1 at SSA rate of 250 t ha−1 in 2016 and 2017, respectively. Although SSA led to accumulation of heavy metals in sweet sorghum, the growth of sorghum was not inhibited even at the highest SSA. In summary, cultivation of bioenergy crop in mudflat amended by sewage sludge is feasible and can be an innovative solution for mudflat reclamation, safe disposal of solid waste, resource reuse and recycle, and bioenergy production.

Up-regulation of lipid biosynthesis increases the oil content in leaves of Sorghum bicolor.

SummarySynthesis and accumulation of the storage lipid triacylglycerol in vegetative plant tissues has emerged as a promising strategy to meet the world's future need for vegetable oil. Sorghum (Sorghum bicolor) is a particularly attractive target crop given its high biomass, drought resistance and C4 photosynthesis. While oilseed‐like triacylglycerol levels have been engineered in the C3 model plant tobacco, progress in C4 monocot crops has been lagging behind. In this study, we report the accumulation of triacylglycerol in sorghum leaf tissues to levels between 3 and 8.4% on a dry weight basis depending on leaf and plant developmental stage. This was achieved by the combined overexpression of genes encoding the Zea mays WRI1 transcription factor, Umbelopsis ramanniana UrDGAT2a acyltransferase and Sesamum indicum Oleosin‐L oil body protein. Increased oil content was visible as lipid droplets, primarily in the leaf mesophyll cells. A comparison between a constitutive and mesophyll‐specific promoter driving WRI1 expression revealed distinct changes in the overall leaf lipidome as well as transitory starch and soluble sugar levels. Metabolome profiling uncovered changes in the abundance of various amino acids and dicarboxylic acids. The results presented here are a first step forward towards the development of sorghum as a dedicated biomass oil crop and provide a basis for further combinatorial metabolic engineering.

Fortification of phenolics, antioxidant activities and biochemical attributes of radish root by plant leaf extract seed priming

Abstract The current study focuses on to the latent potential of Plant Leaf Extract (PLE) to induce growth and antioxidant character in radish root when applied as pre-sowing seed priming agents. The growth behavior in primed seed with PLE of mulberry leaf (mL), Brassica leaf (BL), Sorghum leaf (SL), Moringa leaf (MoL), was regularly monitored whereas, proximate composition, biochemical attributes and antioxidant potential was assessed after 60 days of emergence. Results revealed that PLE based seed priming affect growth physiology consequently improved total phenolic content (TPC), radical scavenging capacity (DPPH IC50) and reducing power of radish root. Overall, seed bio-priming with 3% of MoL for 6 h was found to be the most effective to optimize growth with improved biochemical and antioxidant attributes. So far, seed bio-priming with crude extracts of selected plant leaves may provide viable bioactive fortification choice.