A Symbiotic Meal Containing Extruded Sorghum and Probiotic (Bifidobacterium longum) Ameliorated Intestinal Health Markers in Individuals with Chronic Kidney Disease: A Secondary Analysis of a Subsample from a Previous Randomized and Controlled Clinical Trial.

BACKGROUND: Chronic kidney disease increases uremic toxins concentrations, which have been associated with intestinal dysbiosis. Sorghum bicolor L. Moench has dietary fiber and bioactive compounds, while Bifidobacterium longum can promote beneficial health effects. METHODS: It is a controlled, randomized, and single-blind clinical trial. Thirty-nine subjects were randomly separated into two groups: symbiotic group (SG), which received 100 mL of unfermented probiotic milk with Bifidobacterium longum strain and 40 g of extruded sorghum flakes; and the control group (CG), which received 100 mL of pasteurized milk and 40 g of extruded corn flakes for seven weeks. RESULTS: The uremic toxins decreased, and gastrointestinal symptoms improved intragroup in the SG group. The acetic, propionic, and butyric acid production increased intragroup in the SG group. Regarding α-diversity, the Chao1 index was enhanced in the SG intragroup. The KEGG analysis revealed that symbiotic meal increased the intragroup energy and amino sugar metabolism, in addition to enabling essential amino acid production and metabolism, sucrose degradation, and the biosynthesis of ribonucleotide metabolic pathways. CONCLUSIONS: The consumption of symbiotic meal reduced BMI, improved short-chain fatty acid (SCFA) synthesis and gastrointestinal symptoms, increased diversity according to the Chao1 index, and reduced uremic toxins in chronic kidney disease patients.

Impact of LAB Fermentation on the Nutrient Content, Amino Acid Profile, and Estimated Glycemic Index of Sorghum, Pearl Millet, and Kodo Millet.

INTRODUCTION: Millets, owing to their rich nutritional and low-to-moderate glycemic index values, are termed superfoods; however, some anti-nutritional factors, such as tannins, limit the absorption of micro and macronutrients. Non-thermal processing technologies, such as fermentation, can improve nutrient content and reduce these anti-nutritional factors. METHODS: The effect of a controlled submerged fermentation of whole grain sorghum, pearl millet, and dehusked Kodo millet using mixed lactic acid bacteria (LAB) culture in tofu whey-based media on the proximate, antioxidant, tannin content, vitamin B, amino acids profile and estimated glycemic index (eGI) of different millets were evaluated. RESULTS: The protein content (2-12.5%), carbohydrate content (2-13.6%), antioxidant activity (3-49%), vitamin B complex, amino acid profile (89-90%), and eGI of whole grain sorghum, pearl millet, and dehusked Kodo millet improved due to LAB-assisted submerged fermentation. In contrast, fat (4-15%), ash (56-67%), crude fiber (5-34%), minerals, tannin and resistant starch content decreased due to LAB fermentation. CONCLUSION: Controlled LAB fermentation can improve the nutritional quality of sorghum and millets while reducing anti-nutritional factors. This non-thermal process can be adopted industrially to produce more palatable and nutritionally superior millet products.

Association between Reactive Oxygen Species, Transcription Factors, and Candidate Genes in Drought-Resistant Sorghum.

Drought stress is one of the most severe natural disasters in terms of its frequency, length, impact intensity, and associated losses, making it a significant threat to agricultural productivity. Sorghum (Sorghum bicolor), a C4 plant, shows a wide range of morphological, physiological, and biochemical adaptations in response to drought stress, paving the way for it to endure harsh environments. In arid environments, sorghum exhibits enhanced water uptake and reduced dissipation through its morphological activity, allowing it to withstand drought stress. Sorghum exhibits physiological and biochemical resistance to drought, primarily by adjusting its osmotic potential, scavenging reactive oxygen species, and changing the activities of its antioxidant enzymes. In addition, certain sorghum genes exhibit downregulation capabilities in response to drought stress. Therefore, in the current review, we explore drought tolerance in sorghum, encompassing its morphological characteristics and physiological mechanisms and the identification and selection of its functional genes. The use of modern biotechnological and molecular biological approaches to improving sorghum resistance is critical for selecting and breeding drought-tolerant sorghum varieties.

Genome-wide screening and characterization of phospholipase A (PLA)-like genes in sorghum (Sorghum bicolor L.).

MAIN CONCLUSION: The characterisation of PLA genes in the sorghum genome using in-silico methods revealed their essential roles in cellular processes, providing a foundation for further detailed studies. Sorghum bicolor (L.) Moench is the fifth most cultivated crop worldwide, and it is used in many ways, but it has always gained less popularity due to the yield, pest, and environmental constraints. Improving genetic background and developing better varieties is crucial for better sorghum production in semi-arid tropical regions. This study focuses on the phospholipase A (PLA) family within sorghum, comprehensively characterising PLA genes and their expression across different tissues. The investigation identified 32 PLA genes in the sorghum genome, offering insights into their chromosomal localization, molecular weight, isoelectric point, and subcellular distribution through bioinformatics tools. PLA-like family genes are classified into three groups, namely patatin-related phospholipase A (pPLA), phospholipase A1 (PLA1), and phospholipase A2 (PLA2). In-silico chromosome localization studies revealed that these genes are unevenly distributed in the sorghum genome. Cis-motif analysis revealed the presence of several developmental, tissue and hormone-specific elements in the promoter regions of the PLA genes. Expression studies in different tissues such as leaf, root, seedling, mature seed, immature seed, anther, and pollen showed differential expression patterns. Taken together, genome-wide analysis studies of PLA genes provide a better understanding and critical role of this gene family considering the metabolic processes involved in plant growth, defence and stress response.

Mitigation of drought stress in maize and sorghum by humic acid: differential growth and physiological responses.

BACKGROUND: Drought is a major determinant for growth and productivity of all crops, including cereals, and the drought-induced detrimental effects are anticipated to jeopardize world food security under the ongoing global warming scenario. Biostimulants such as humic acid (HA) can improve drought tolerance in many cereals, including maize and sorghum. These two plant species are genetically related; however, maize is more susceptible to drought than sorghum. The physiological and biochemical mechanisms underlying such differential responses to water shortage in the absence and presence of HA, particularly under field conditions, are not fully understood. RESULTS: Herein, the effects of priming maize and sorghum seeds in 100 mg L-1 HA on their vegetative growth and physiological responses under increased levels of drought (100%, 80%, and 60% field capacity) were simultaneously monitored in the field. In the absence of HA, drought caused 37.0 and 58.7% reductions in biomass accumulation in maize compared to 21.2 and 32.3% in sorghum under low and high drought levels, respectively. These responses were associated with differential retardation in overall growth, relative water content (RWC), photosynthetic pigments and CO2 assimilation in both plants. In contrast, drought increased root traits as well as H2O2, malondialdehyde, and electrolyte leakage in both species. HA treatment significantly improved the growth of both plant species under well-watered and drought conditions, with maize being more responsive than sorghum. HA induced a 29.2% increase in the photosynthetic assimilation rate in maize compared to 15.0% in sorghum under high drought level. The HA-promotive effects were also associated with higher total chlorophyll, stomatal conductance, RWC, sucrose, total soluble sugars, total carbohydrates, proline, and total soluble proteins. HA also reduced the drought-induced oxidative stress via induction of non-enzymic and enzymic antioxidants at significantly different extents in maize and sorghum. CONCLUSION: The current results identify significant quantitative differences in a set of critical physiological biomarkers underlying the differential responses of field-grown maize and sorghum plants against drought. They also reveal the potential of HA priming as a drought-alleviating biostimulant and as an effective approach for sustainable maize and sorghum production and possibly other crops in drought-affected lands.

Brown midrib (BMR) and plant age impact fall armyworm (Spodoptera frugiperda) growth and development in sorghum-sudangrass (Sorghum x drummondii).

Economic losses from insect herbivory in agroecosystems has driven the development of integrated pest management strategies that reduce pest incidence and damage; however, traditional chemicals-based control is either being complemented or substituted with sustainable and integrated methods. Major sustainable pest management strategies revolve around improving host plant resistance, and one of these traits of interest is Brown midrib (BMR). Originally developed to increase nutritional value and ease of digestion for animal agriculture, BMR is a recessive plant gene usually found in annual grasses, including sorghum and sorghum-sudangrass hybrids. In sorghum-sudangrass, BMR expressed plants have lower amounts of lignin, which produces a less fibrous, more digestible crop, with possible implications for plant defense against herbivores- an area currently unexplored. Fall Armyworm (FAW; Spodoptera frugiperda) is a ruinous pest posing immense threat for sorghum producers by severely defoliating crops and being present in every plant stage. Using FAW, we tested the effect of seed treatment, BMR, and plant age on FAW growth, development, and plant defense responses in sorghum-sudangrass. Our results show that seed treatment did not affect growth or development, or herbivory. However, presence of BMR significantly reduced pupal mass relative to its non-BMR counterpart, alongside a significant reduction in adult mass. We also found that plant age was a major factor as FAW gained significantly less mass, had longer pupation times, and had lower pupal mass on the oldest plant stage explored, 60-days, compared to younger plants. These findings collectively show that pest management strategies should consider plant age, and that the effects of BMR on plant defenses should also be studied.

Genome-wide association study and expression of candidate genes for Fe and Zn concentration in sorghum grains.

Sorghum germplasm showed grain Fe and Zn genetic variability, but a few varieties were biofortified with these minerals. This work contributes to narrowing this gap. Fe and Zn concentrations along with 55,068 high-quality GBS SNP data from 140 sorghum accessions were used in this study. Both micronutrients exhibited good variability with respective ranges of 22.09-52.55 ppm and 17.92-43.16 ppm. Significant marker-trait associations were identified on chromosomes 1, 3, and 5. Two major effect SNPs (S01_72265728 and S05_58213541) explained 35% and 32% of Fe and Zn phenotypic variance, respectively. The SNP S01_72265728 was identified in the cytochrome P450 gene and showed a positive effect on Fe accumulation in the kernel, while S05_58213541 was intergenic near Sobic.005G134800 (zinc-binding ribosomal protein) and showed negative effect on Zn. Tissue-specific in silico expression analysis resulted in higher levels of Sobic.003G350800 gene product in several tissues such as leaf, root, flower, panicle, and stem. Sobic.005G188300 and Sobic.001G463800 were expressed moderately at grain maturity and anthesis in leaf, root, panicle, and seed tissues. The candidate genes expressed in leaves, stems, and grains will be targeted to improve grain and stover quality. The haplotypes identified will be useful in forward genetics breeding.

Influence of fermentation conditions, and the blends of sorghum and carrot pulp supplementation on the nutritional and sensory quality of tef injera.

Tef [Eragrostis tef (Zucc.) Trotter], an ancient cereal primarily grown in Ethiopia, is becoming increasingly popular worldwide due to its high iron content and gluten-free nature. However, it has been reported that injera produced only with tef flour lack certain vital nutrients. Therefore, this specific study was conducted to supplement tef injera with other food materials of better nutritional value and compensate its expensive market price with sorghum cereal flour. The effect of fermentation conditions, and the sorghum and carrot pulp blending ratio on the nutritional value and sensory quality of tef injera was investigated. The factorial approach of the experimental design was conducted considering the nutritional value and sensory quality of the injera made of three main blending ratios of tef, sorghum, and carrot (60% tef: 30% sorghum: 10% carrot pulp, 45% tef: 45% sorghum: 10% carrot pulp and 30% tef: 60% sorghum: 10% carrot pulp) as experiential variables. The raw materials and injera were characterised for their proximate composition, physicochemical property, mineral composition, microbial analysis, and sensory attributes, using standard methods. The results of the study show that fermentation conditions and blending ratios have a significant effect on the nutritional, anti-nutritional, mineral content, microbial quality, and sensory properties of blended injera products, where higher values of ash, crude protein, crude fat, Total titratable acidity (TTA), Fe, Zn, and Ca (2.30%, 11.34%, 2.62%, 3.53, 32.97 mg/100 g, 2.98 mg/100 g and 176.85 mg/100 g, respectively) were analyzed for the co-fermented injera sample. In addition, a lower microbial count was observed in co-fermented injera samples, whereas microbial counts in injera samples prepared from carrot pulp-supplemented dough after the co-fermentation of tef and sorghum flours were observed to be higher. The injera product made using blending ratio of 60% tef: 30%sorghum: 10% carrot co-fermented was found to be the optimum result due to its very good nutritional improvement (i.e., reduction of some anti-nutritional factors, microbial contents, pH and increased contents of some minerals, crude protein, crude fat, TTA and improved most of the sensory quality of the supplemented injera product). According to this study, sorghum and carrot supplementation on tef could improve the nutritional value of injera while also providing an instant remedy for the growing price of tef.

The contrasting photosynthesis and growth response of young test species irrigated with electro-chemical modified water.

The study evaluated the effects of treating irrigation water with a coaxial flow variator (CFV) on the morpho-physiology of pot-cultivated test species, including cucumber (Cucumis sativus, CU), lettuce (Lactuca sativa, LE), and sorghum (Sorghum vulgare, SO), in early stages of growth. CFV caused a lower oxidation reduction potential (ORP), increased pH and flow resistance and inductance. It induced changes in the absorbance characteristics of water in specific spectral regions, likely associated with greater stretching and reduced bending vibrations compared to untreated water. While assimilation rate and photosynthetic efficiency were not significantly affected at 60 days after sowing, treated water increased the stomatal conductance to water vapour gsw (+79%) and the electron transport rate ETR (+10%) in CU, as well as the non-photochemical quenching NPQ (+33%) in SO. Treated water also reduced leaf temperature in all species (-0.86 °C on average). This translated into improved plant biomass (leaves: +34%; roots: +140%) and reduced leaf-to-root biomass ratio (-42%) in SO, allowing both faster aerial growth and soil colonization, which can be exploited to improve plant tolerance against abiotic stresses. In the C3 species CU and LE, plant biomass was instead reduced, although significantly in LE only, while the leaf-to-root biomass ratio was generally enhanced, a result likely profitable in the cultivation of leafy vegetables. This is a preliminary trial on the effects of functionalized water and much remains to be investigated in other physiological processes, plant species, and growth stages for the full exploitation of this water treatment in agronomy.

Revealing critical mechanisms in determining sorghum resistance to drought and salt using mRNA, small RNA and degradome sequencing.

BACKGROUND: Plant growth and development are severely threatened by drought and salt stresses. Compared with structural genes, transcription factors (TFs) play more pivotal roles in plant growth and stress adaptation. However, the underlying mechanisms of sorghum adapting to drought and salt are insufficient, and systematic analysis of TFs in response to the above stresses is lacking. RESULTS: In this study, TFs were identified in sorghum and model plants (Arabidopsis thaliana and rice), and gene number and conserved domain were compared between sorghum and model plants. According to syntenic analysis, the expansion of sorghum and rice TFs may be due to whole-genome duplications. Between sorghum and model plants TFs, specific conserved domains were identified and they may be related to functional diversification of TFs. Forty-five key genes in sorghum, including four TFs, were likely responsible for drought adaption based on differently expression analysis. MiR5072 and its target gene (Sobic.001G449600) may refer to the determination of sorghum drought resistance according to small RNA and degradome analysis. Six genes were associated with drought adaptation of sorghum based on weighted gene co-expression network analysis (WGCNA). Similarly, the core genes in response to salt were also characterized using the above methods. Finally, 15 candidate genes, particularly two TFs (Sobic.004G300300, HD-ZIP; Sobic.003G244100, bZIP), involved in combined drought and salt resistance of sorghum were identified. CONCLUSIONS: In summary, the findings in this study help clarify the molecular mechanisms of sorghum responding to drought and salt. We identified candidate genes and provide important genetic resource for potential development of drought-tolerant and salt-tolerant sorghum plants.

Detecting sorghum aphid infestation in grain sorghum using leaf spectral response.

Sorghum aphid, Melanaphis sorghi (Theobald) have become a major economic pest in sorghum causing 70% yield loss without timely insecticide applications. The overarching goal is to develop a monitoring system for sorghum aphids using remote sensing technologies to detect changes in plant-aphid density interactions, thereby reducing scouting time. We studied the effect of aphid density on sorghum spectral responses near the feeding site and on distal leaves from infestation and quantified potential systemic effects to determine if aphid feeding can be detected. A leaf spectrometer at 400-1000 nm range was used to measure reflectance changes by varying levels of sorghum aphid density on lower leaves and those distant to the caged infestation. Our study results demonstrate that sorghum aphid infestation can be determined by changes in reflected light, especially between the green-red range (550-650 nm), and sorghum plants respond systemically. This study serves as an essential first step in developing more effective pest monitoring systems for sorghum aphids, as leaf reflection sensors can be used to identify aphid feeding regardless of infestation location on the plant. Future research should address whether such reflectance signatures can be detected autonomously using small unmanned aircraft systems or sUAS equipped with comparable sensor technologies.

Silicon mitigates salinity effects on sorghum-sudangrass (Sorghum bicolor × Sorghum sudanense) by enhancing growth and photosynthetic efficiency.

The aim of this study was to investigate whether silicon (Si) supply was able to alleviate the harmful effects caused by salinity stress on sorghum-sudangrass (Sorghum bicolor ×Sorghum sudanense ), a species of grass raised for forage and grain. Plants were grown in the presence or absence of 150mM NaCl, supplemented or not with Si (0.5mM Si). Biomass production, water and mineral status, photosynthetic pigment contents, and gas exchange parameters were investigated. Special focus was accorded to evaluating the PSI and PSII. Salinity stress significantly reduced plant growth and tissue hydration, and led to a significant decrease in all other studied parameters. Si supply enhanced whole plant biomass production by 50%, improved water status, decreased Na+ and Cl- accumulation, and even restored chlorophyll a , chlorophyll b , and carotenoid contents. Interestingly, both photosystem activities (PSI and PSII) were enhanced with Si addition. However, a more pronounced enhancement was noted in PSI compared with PSII, with a greater oxidation state upon Si supply. Our findings confirm that Si mitigated the adverse effects of salinity on sorghum-sudangrass throughout adverse approaches. Application of Si in sorghum appears to be an efficient key solution for managing salt-damaging effects on plants.

Combining transcriptome and metabolome analysis to understand the response of sorghum to Melanaphis sacchari.

BACKGROUND: The sorghum aphid Melanaphis sacchari (Zehntner) (Homoptera: Aphididae) is an important insect in the late growth phase of sorghum (Sorghum bicolor L.). However, the mechanisms of sorghum response to aphid infestation are unclear. RESULTS: In this paper, the mechanisms of aphid resistance in different types of sorghum varieties were revealed by studying the epidermal cell structure and performing a transcriptome and metabolome association analysis of aphid-resistant and aphid-susceptible varieties. The epidermal cell results showed that the resistance of sorghum to aphids was positively correlated with epidermal cell regularity and negatively correlated with the intercellular space and leaf thickness. Transcriptome and metabolomic analyses showed that differentially expressed genes in the resistant variety HN16 and susceptible variety BTX623 were mainly enriched in the flavonoid biosynthesis pathway and differentially expressed metabolites were mainly related to isoflavonoid biosynthesis and flavonoid biosynthesis. The q-PCR results of key genes were consistent with the transcriptome expression results. Meanwhile, the metabolome test results showed that after aphidinfestation, naringenin and genistein were significantly upregulated in the aphid-resistant variety HN16 and aphid-susceptible variety BTX623 while luteolin was only significantly upregulated in BTX623. These results show that naringenin, genistein, and luteolin play important roles in plant resistance to aphid infestation. The results of exogenous spraying tests showed that a 1‰ concentration of naringenin and genistein is optimal for improving sorghum resistance to aphid feeding. CONCLUSIONS: In summary, the physical properties of the sorghum leaf structure related to aphid resistance were studied to provide a reference for the breeding of aphid-resistant varieties. The flavonoid biosynthesis pathway plays an important role in the response of sorghum aphids and represents an important basis for the biological control of these pests. The results of the spraying experiment provide insights for developing anti-aphid substances in the future.

Multi-trait association mapping for phosphorous efficiency reveals flexible root architectures in sorghum.

BACKGROUND: On tropical regions, phosphorus (P) fixation onto aluminum and iron oxides in soil clays restricts P diffusion from the soil to the root surface, limiting crop yields. While increased root surface area favors P uptake under low-P availability, the relationship between the three-dimensional arrangement of the root system and P efficiency remains elusive. Here, we simultaneously assessed allelic effects of loci associated with a variety of root and P efficiency traits, in addition to grain yield under low-P availability, using multi-trait genome-wide association. We also set out to establish the relationship between root architectural traits assessed in hydroponics and in a low-P soil. Our goal was to better understand the influence of root morphology and architecture in sorghum performance under low-P availability. RESULT: In general, the same alleles of associated SNPs increased root and P efficiency traits including grain yield in a low-P soil. We found that sorghum P efficiency relies on pleiotropic loci affecting root traits, which enhance grain yield under low-P availability. Root systems with enhanced surface area stemming from lateral root proliferation mostly up to 40 cm soil depth are important for sorghum adaptation to low-P soils, indicating that differences in root morphology leading to enhanced P uptake occur exactly in the soil layer where P is found at the highest concentration. CONCLUSION: Integrated QTLs detected in different mapping populations now provide a comprehensive molecular genetic framework for P efficiency studies in sorghum. This indicated extensive conservation of P efficiency QTL across populations and emphasized the terminal portion of chromosome 3 as an important region for P efficiency in sorghum. Increases in root surface area via enhancement of lateral root development is a relevant trait for sorghum low-P soil adaptation, impacting the overall architecture of the sorghum root system. In turn, particularly concerning the critical trait for water and nutrient uptake, root surface area, root system development in deeper soil layers does not occur at the expense of shallow rooting, which may be a key reason leading to the distinctive sorghum adaptation to tropical soils with multiple abiotic stresses including low P availability and drought.

Nitrogenous fertilizer plays a more important role than cultivars in shaping sorghum-associated microbiomes.

The plant microbiome plays a crucial role in facilitating plant growth through enhancing nutrient cycling, acquisition and transport, as well as alleviating stresses induced by nutrient limitations. Despite its significance, the relative importance of common agronomic practices, such as nitrogenous fertilizer, in shaping the plant microbiome across different cultivars remains unclear. This study investigated the dynamics of bacterial and fungal communities in leaf, root, rhizosphere, and bulk soil in response to nitrogenous fertilizer across ten sorghum varieties, using 16S rRNA and ITS gene amplicon sequencing, respectively. Our results revealed that nitrogen addition had a greater impact on sorghum-associated microbial communities compared to cultivar. Nitrogen addition significantly reduced bacterial diversity in all compartments except for the root endophytes. However, N addition significantly increased fungal diversity in both rhizosphere and bulk soils, while significantly reducing fungal diversity in the root endophytes. Furthermore, N addition significantly altered the community composition of bacteria and fungi in all four compartments, while cultivars only affected the community composition of root endosphere bacteria and fungi. Network analysis revealed that fertilization significantly reduced microbial network complexity and increased fungal-related network complexity. Collectively, this study provides empirical evidence that sorghum-associated microbiomes are predominantly shaped by nitrogenous fertilizer rather than by cultivars, suggesting that consistent application of nitrogenous fertilizer will ultimately alter plant-associated microbiomes regardless of cultivar selection.

Screening of plant growth-promoting rhizobacteria helps alleviate the joint toxicity of PVC+Cd pollution in sorghum plants.

Combined microplastic and heavy metal pollution (CM-HP) has become a popular research topic due to the ability of these pollutants to have complex interactions. Plant growth-promoting rhizobacteria (PGPR) are widely used to alleviate stress from heavy metal pollution in plants. However, the effects and mechanisms by which these bacteria interact under CM-HP have not been extensively studied. In this study, we isolated and screened PGPR from CM-HP soils and analyzed the effects of these PGPR on sorghum growth and Cd accumulation under combined PVC+Cd pollution through pot experiments. The results showed that the length and biomass of sorghum plants grown in PVC+Cd contaminated soil were significantly lower than those grown in soils contaminated with Cd alone, revealing an enhancement in toxicity when the two contaminants were mixed. Seven isolated and screened PGPR strains effectively alleviated stress due to PVC+Cd contamination, which resulted in a significant enhancement in sorghum biomass. PGPR mitigated the decrease in soil available potassium, available phosphorus and alkali-hydrolyzable nitrogen content caused by combined PVC+Cd pollution and increased the contents of these soil nutrients. Soil treatment with combined PVC+Cd pollution and PGPR inoculation can affect rhizosphere bacterial communities and change the composition of dominant populations, such as Proteobacteria, Firmicutes, and Actinobacteria. PICRUSt2 functional profile prediction revealed that combined PVC+Cd pollution and PGPR inoculation affected nitrogen fixation, nitrification, denitrification, organic phosphorus mineralization, inorganic phosphorus solubilization and the composition and abundance of genes related the N and P cycles. The Mantel test showed that functional strain abundance, the diversity index and N and P cycling-related genes were affected by test strain inoculation and were significant factors affecting sorghum growth, Cd content and accumulation. This study revealed that soil inoculation with isolated and screened PGPR can affect the soil inorganic nutrient content and bacterial community composition, thereby alleviating the stress caused by CM-HP and providing a theoretical basis and data support for the remediation of CM-HP.

Does sorghum phenolic extract have antifungal effect?

This study aimed to evaluate the antifungal effect of SC319 sorghum phenolic extract (SPE) on the Aspergillus, Fusarium, Penicillium, Stenocarpella, Colletotrichum, and Macrophomina genera. SPE was extracted by 20% ethanol and used in four assays: (1) against Fusarium verticillioides in solid (PDA) and liquid (PD) potato dextrose media; (2) Minimum Inhibitory Concentration (MIC) assay with 16 fungi isolates; (3) Conidial Germination Rate (CGR) with 14 fungi isolates and (4) Growth Curve (GC) with 11 fungi isolates. There was no reduction in the mycelial growth (colony diameter and dry weight) and in the number of Fusarium verticillioides spores in assay 1 (PDA and PD). The colony's dry weight was almost six times higher in the presence than in the absence of SPE. All SPE samples presented MIC (assay 1) above the maximum concentration tested (5000 µg.mL-1) for the 16 isolates. Also, there was no inhibitory effect of SPE on conidia germination rate (CGR). Oppositely, in GC assay, the control had a higher CFU count than the samples with SPE in 24 h. This result suggests that SPE can delay the fungal growth in the first hours of incubation, which is an important finding that may help reduce the severity of fungal diseases in plants. However, further studies are needed to confirm these results, including sorghum genotypes with different profiles of phenolic compounds. Although the SC319 SPE was not effective as an antifungal agent, it may have potential as a growth promoter of beneficial fungi in the food and pharmaceutical industries.

Identification and functional marker development of SbPLSH1 conferring purple leaf sheath in sorghum.

KEY MESSAGE: We identified a SbPLSH1gene conferring purple leaf sheath in sorghum (sorghumbicolor(L.) Moench)and developed a functional markerfor it. The purple leaf sheath of sorghum, a trait mostly related to anthocyanin deposition, is a visually distinguishable morphological marker widely used to evaluate the purity of crop hybrids. We aimed to dissect the genetic mechanism for leaf sheath color to mine the genes regulating this trait. In this study, two F2 populations were constructed by crossing a purple leaf sheath inbred line (Gaoliangzhe) with two green leaf sheath inbred lines (BTx623 and Silimei). Based on the results of bulked-segregant analysis sequencing, bulk-segregant RNA sequencing, and map-based cloning, SbPLSH1 (Sobic.006G175700), which encodes a bHLH transcription factor on chromosome 6, was identified as the candidate gene for purple leaf sheath in sorghum. Genetic analysis demonstrated that overexpression of SbPLSH1 in Arabidopsis resulted in anthocyanin deposition and purple petiole, while two single-nucleotide polymorphism (SNP) variants on the exon 6 resulted in loss of function. Further haplotype analysis revealed that there were two missense mutations and one cis-acting element mutation in SbPLSH1, which are closely associated with leaf sheath color in sorghum. Based on the variations, a functional marker (LSC4-2) for marker-assisted selection was developed, which has a broad-spectrum capability of distinguishing leaf sheath color in natural variants. In summary, this study lays a foundation for analyzing the genetic mechanism for sorghum leaf sheath color.

Photostability and photodynamic antimicrobial profile of dye extracts from four (4) plants: prospects for eco-friendly low-cost food disinfection and topical biomedical applications.

In this study, photostability and photodynamic antimicrobial performance of dye extracts from Hibiscus sabdariffa (HS) calyces, Sorghum bicolor (SB) leaf sheaths, Lawsonia inermis (LI) leaves and Curcuma longa (CL) roots were investigated in Acetate-HCl (AH) Buffer (pH 4.6), Tris Base-HCl (TBH) Buffer (pH 8.6), distilled water (dH2O), and Phosphate Buffer Saline (PBS, pH 7.2) using Bacillus subtilis as model for gram positive bacteria, Escherichia coli as model for gram negative bacteria, phage MS2 as model for non-envelope viruses and phage phi6 as model for envelope viruses including SARS CoV-2 which is the causative agent of COVID-19. Our results showed that the photostability of the dye extracts is in the decreasing order of LI > CL > SB > HS. The dye extract-HS is photostable in dH2O but bleaches in buffers-AH, TBH and PBS. The rate of bleaching is higher in AH compared to in TBH and PBS. The bleaching and buffers affected the photodynamic and non-photodynamic antimicrobial activity of the dye extracts. The photodynamic antibacterial activity of the dye extracts is in the decreasing order of CL > HS > LI > SB while the non-photodynamic antibacterial activity is in the decreasing order of LI > CL > HS > SB. The non-photodynamic antiviral activity pattern observed is the same as that of non-photodynamic antibacterial activity observed. However, the photodynamic antiviral activity of the dye extracts is in the decreasing order of CL > LI > HS > SB. Given their performance, the dye extracts maybe mostly suitable for environmental applications including fresh produce and food disinfection, sanitation of hands and contact surfaces where water can serve as diluent for the extracts and the microenvironment is free of salts.

Sorghum drought tolerance is enhanced by cerium oxide nanoparticles via stomatal regulation and osmolyte accumulation.

Sorghum [Sorghum bicolor (L.) Moench] yield is limited by the coincidence of drought during its sensitive stages. The use of cerium oxide nanoparticles in agriculture is minimal despite its antioxidant properties. We hypothesize that drought-induced decreases in photosynthetic rate in sorghum may be associated with decreased tissue water content and organelle membrane damage. We aimed to quantify the impact of foliar application of nanoceria on transpiration rate, accumulation of compatible solutes, photosynthetic rate and reproductive success under drought stress in sorghum. In order to ascertain the mechanism by which nanoceria mitigate drought-induced inhibition of photosynthesis and reproductive success, experiments were undertaken in a factorial completely randomized design or split-plot design. Foliar spray of nanoceria under progressive soil drying conserved soil moisture by restricting the transpiration rate than water spray, indicating that nanoceria exerted strong stomatal control. Under drought stress at the seed development stage, foliar application of nanoceria at 25 mg L-1 significantly improved the photosynthetic rate (19%) compared to control by maintaining a higher tissue water content (18%) achieved by accumulating compatible solutes. The nanoceria-sprayed plants exhibited intact chloroplast and thylakoid membranes because of increased heme enzymes [catalase (53%) and peroxidase (45%)] activity, which helped in the reduction of hydrogen peroxide content (74%). Under drought, compared to water spray, nanoceria improved the seed-set percentage (24%) and individual seed mass (27%), eventually causing a higher seed yield. Thus, foliar application of nanoceria at 25 mg L-1 under drought can increase grain yield through increased photosynthesis and reproductive traits.