Abiotic stress tolerance in pearl millet: Unraveling molecular mechanisms via transcriptomics.

Pearl millet (Pennisetum glaucum (L.)) is a vital cereal crop renowned for its ability to thrive in challenging environmental conditions; however, the molecular mechanisms governing its salt stress tolerance remain poorly understood. To address this gap, next-generation RNA sequencing was conducted to compare gene expression patterns in pearl millet seedlings exposed to salt stress with those grown under normal conditions. Our RNA sequencing analysis focused on shoots from 13-day-old pearl millet plants subjected to either salinity stress (150 mmol of NaCl for 3 days) or thermal stress (50°C for 60 s). Of 36,041 genes examined, 17,271 genes with fold changes ranging from 2.2 to 19.6 were successfully identified. Specifically, 2388 genes were differentially upregulated in response to heat stress, whereas 4327 genes were downregulated. Under salt stress conditions, 2013 genes were upregulated and 4221 genes were downregulated. Transcriptomic analysis revealed four common abiotic KEGG pathways that play crucial roles in the response of pearl millet to salt and heat stress: phenylpropanoid biosynthesis, photosynthesis-antenna proteins, photosynthesis, and plant hormone signal transduction. These metabolic pathways are necessary for pearl millet to withstand and adapt to abiotic stresses caused by salt and heat. Moreover, the pearl millet shoot heat stress group showed specific transcriptomics related to KEEG metabolic pathways such as cytochrome P450, cutin, suberine, and wax biosynthesis, zeatin biosynthesis, crocin biosynthesis, ginsenoside biosynthesis, saponin biosynthesis, and biosynthesis of various plant secondary metabolites. In contrast, pearl millet shoots exposed to salinity stress exhibited transcriptomic changes associated with KEEG metabolic pathways related to carbon fixation in photosynthetic organisms, mismatch repair, and nitrogen metabolism. Our findings underscore the remarkable cross-tolerance of pearl millet to simultaneous salt and heat stress, elucidated through the activation of shared abiotic KEGG pathways. This study emphasizes the pivotal role of transcriptomics analysis in unraveling the molecular responses of pearl millet under abiotic stress conditions.

Comprehensive genomic analysis of Bacillus subtilis and Bacillus paralicheniformis associated with the pearl millet panicle reveals their antimicrobial potential against important plant pathogens.

BACKGROUND: Plant microbiome confers versatile functional roles to enhance survival fitness as well as productivity. In the present study two pearl millet panicle microbiome member species Bacillus subtilis PBs 12 and Bacillus paralicheniformis PBl 36 found to have beneficial traits including plant growth promotion and broad-spectrum antifungal activity towards taxonomically diverse plant pathogens. Understanding the genomes will assist in devising a bioformulation for crop protection while exploiting their beneficial functional roles. RESULTS: Two potential firmicute species were isolated from pearl millet panicles. Morphological, biochemical, and molecular characterization revealed their identities as Bacillus subtilis PBs 12 and Bacillus paralicheniformis PBl 36. The seed priming assays revealed the ability of both species to enhance plant growth promotion and seedling vigour index. Invitro assays with PBs 12 and PBl 36 showed the antibiosis effect against taxonomically diverse plant pathogens (Magnaporthe grisea; Sclerotium rolfsii; Fusarium solani; Alternaria alternata; Ganoderma sp.) of crops and multipurpose tree species. The whole genome sequence analysis was performed to unveil the genetic potential of these bacteria for plant protection. The complete genomes of PBs 12 and PBl 36 consist of a single circular chromosome with a size of 4.02 and 4.33 Mb and 4,171 and 4,606 genes, with a G + C content of 43.68 and 45.83%, respectively. Comparative Average Nucleotide Identity (ANI) analysis revealed a close similarity of PBs 12 and PBl 36 with other beneficial strains of B. subtilis and B. paralicheniformis and found distant from B. altitudinis, B. amyloliquefaciens, and B. thuringiensis. Functional annotation revealed a majority of pathway classes of PBs 12 (30) and PBl 36 (29) involved in the biosynthesis of secondary metabolites, polyketides, and non-ribosomal peptides, followed by xenobiotic biodegradation and metabolism (21). Furthermore, 14 genomic regions of PBs 12 and 15 of PBl 36 associated with the synthesis of RiPP (Ribosomally synthesized and post-translationally modified peptides), terpenes, cyclic dipeptides (CDPs), type III polyketide synthases (T3PKSs), sactipeptides, lanthipeptides, siderophores, NRPS (Non-Ribosomal Peptide Synthetase), NRP-metallophone, etc. It was discovered that these areas contain between 25,458 and 33,000 secondary metabolite-coding MiBiG clusters which code for a wide range of products, such as antibiotics. The PCR-based screening for the presence of antimicrobial peptide (cyclic lipopeptide) genes in PBs 12 and 36 confirmed their broad-spectrum antifungal potential with the presence of spoVG, bacA, and srfAA AMP genes, which encode antimicrobial compounds such as subtilin, bacylisin, and surfactin. CONCLUSION: The combined in vitro studies and genome analysis highlighted the antifungal potential of pearl millet panicle-associated Bacillus subtilis PBs12 and Bacillus paralicheniformis PBl36. The genetic ability to synthesize several antimicrobial compounds indicated the industrial value of PBs 12 and PBl 36, which shed light on further studies to establish their action as a biostimulant for crop protection.

Combined exposure of PVC-microplastic and mercury chloride (HgCl2) in sorghum (Pennisetum glaucum L.) when its seeds are primed titanium dioxide nanoparticles (TiO2-NPs).

The present work studied the impact of different levels of PVC-microplastics (PVC-MPs), namely 0 (no PVC-MPs), 2, and 4 mg L-1, along with mercury (Hg) levels of 0 (no Hg), 10, and 25 mg kg-1 in the soil, while concurrently applying titanium dioxide-nanoparticles (TiO2-NPs) at 0 (no TiO2-NPs), 50, and 100 µg mL-1 to sorghum (Pennisetum glaucum L.) plants. This study aimed to examine plant growth and biomass, photosynthetic pigments and gas exchange characteristics, oxidative stress indicators, and the response of various antioxidants (enzymatic and non-enzymatic) and their specific gene expression, proline metabolism, the AsA-GSH cycle, and cellular fractionation in the plants. The research outcomes indicated that elevated levels of PVC-MPs and Hg stress in the soil notably reduced plant growth and biomass, photosynthetic pigments, and gas exchange attributes. However, PVC-MPs and Hg stress also induced oxidative stress in the roots and shoots of the plants by increasing malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage (EL) which also induced increased compounds of various enzymatic and non-enzymatic antioxidants and also the gene expression and sugar content. Furthermore, a significant increase in proline metabolism, the AsA-GSH cycle, and the pigmentation of cellular components was observed. Although, the application of TiO2-NPs showed a significant increase in plant growth and biomass, gas exchange characteristics, enzymatic and non-enzymatic compounds, and their gene expression and also decreased oxidative stress. In addition, the application of TiO2-NPs enhanced cellular fractionation and decreased the proline metabolism and AsA-GSH cycle in P. glaucum plants. These results open new insights for sustainable agriculture practices and hold immense promise in addressing the pressing challenges of heavy metal contamination in agricultural soils.

Purple Napiergrass (Pennisetum purpureum Schumach) Hot Water Extracts Ameliorate High-Fat Diet-Induced Obesity and Metabolic Disorders in Mice.

Purple Pennisetum (Pennisetum purpureum Schumach), a hybrid between Taihucao No. 2 and the local wild species of purple Pennisetum, has dark red stems and leaves due to its anthocyanin content. This study explores the potential of purple napiergrass extracts (PNE) in alleviating obesity and metabolic disorders induced by a high-fat diet in mice, where 50% of the caloric content is derived from fat. Mice were orally administered low-dose or high-dose PNE alongside a high-fat diet. Experimental findings indicate that PNE attenuated weight gain, reduced liver, and adipose tissue weight, and lowered blood cholesterol, triglyceride, low-density lipoprotein, and blood sugar levels. Stained sections showed that PNE inhibited lipid accumulation and fat hypertrophy in the liver. Immunoblotting analysis suggested that PNE improved the inflammatory response associated with obesity, dyslipidemia, and hyperglycemia induced by a high-fat diet. Furthermore, PNE potentially functions as a PPAR-γ agonist, increasing the adiponectin (ADIPOQ) concentration and suppressing inflammatory factors, while elevating the anti-inflammatory factor interleukin-10 (IL-10) in the liver. PNE-treated mice showed enhanced activation of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) and AMP-activated protein kinase (AMPK) pathways and increased fatty acid oxidation and liver lipolysis. In conclusion, this study elucidated the mechanisms underlying the anti-inflammatory, PI3K/Akt, and AMPK pathways in a high-fat diet-induced obesity model. These findings highlight the potential of PNE in reducing weight, inhibiting inflammation, and improving blood sugar and lipid levels, showing the potential for addressing obesity-related metabolic disorders in humans.

[Effects of Combined Pollution of Microplastics and Cadmium on Microbial Community Structure and Function of Pennisetum hydridum Rhizosphere Soil].

The combined pollution of microplastics and heavy metals can potentially interact. This may have an important impact on the growth and development of plants and the rhizosphere microbial community and function. In this study, the effects of heavy metal cadmium combined with different types of microplastics(PE and PS), different particle sizes(13 µm and 550 µm), and different concentrations(0.1% and 1%) on Pennisetum hydridum growth were studied under pot conditions. The results showed that the effects of the combined pollution of MPs and Cd on plant dry weight and Cd accumulation varied with different types, concentrations, and particle sizes of MPs, and the combined pollution stress increased, whereas the Cd content and Cd accumulation decreased. Metagenomic analysis showed that the combined contamination of MPs and Cd could change the composition of the bacterial community and reduce bacterial diversity, among which the ACE index and Chao1 index in the 550 µm 0.1% PE+Cd treatment group were the most significant. Metagenomic analysis of microbial species function showed that the main functional groups were metabolism, amino acid transport and metabolism, energy generation and conversion, and signal transduction mechanisms. Compared with that under single Cd pollution, the addition of MPs could change the gene abundance of functional groups such as metabolism, amino acid transport and metabolism, and energy generation and conversion, and the effects of different MPs types, concentrations, and particle sizes varied. In this study, metagenomics and amplification sequencing were used to analyze the effects of the combined pollution of MPs and Cd on the bacterial community and function in P. hydridum in order to provide basic data and scientific basis for the ecotoxicological effects of the combined heavy metal pollution of MPs and its biological remediation.

Iron and zinc biofortification of rice by synergistic expression of OsNAS2 gene with monocot (Pennisetum glaucum) and dicot (Phaseolus vulgaris) ferritins.

Iron and zinc deficiencies are the most prevalent cause of global hidden hunger. Rice, being one of the most consumed crops worldwide, is suitable to target for Fe and Zn biofortification. In present study, we generated rice transgenic lines to meet the recommended dietary requirement of iron and zinc through endosperm specific expression of dicot (kidney bean) and monocot (pearl millet) Ferritins along with constitutive expression of rice nicotianamine synthase 2 (OsNAS2) gene. Visualization through perls' prussian staining and quantification by ICP-MS showed significant improvement in grain iron content in all the transgenic lines. The transgenic lines expressing any of the three selected gene combinations (PvFerrtin-OsNAS2, feedPgFerrtin-OsNAS2 and foodPgFerritin-OsNAS2), showed the potential to surpass the 30% of the estimated average requirement (13 µg/g Fe and 28 µg/g Zn) proposed for rice in HarvestPlus breeding program. Though the expression of PvFerritin along with OsNAS2 gene in IET10364 (indica) variety showed the best result, providing up to 4.2- and 3.5-fold increase in iron (30.56 µg/g) and zinc (60.1 µg/g) content, respectively; in polished grains compared to non-transgenic control. Thus, the lines developed in our study can be used for further breeding purpose to enhance the iron and zinc content in commercial rice varieties.

Effects of pin-to-plate atmospheric cold plasma for modification of pearl millet (Pennisetum glaucum) starch.

The present study was done to analyze the effect of atmospheric pressure non-thermal pin-to-plate plasma at a range of different voltages (170, 200, and 230V) at different time intervals (10, 20, and 30 mins) on under-utilized pearl millet starch. The untreated and treated starches were analyzed for amylose content, pH, carbonyl, and carboxyl group, reducing sugar, turbidity, water, and oil binding property, pasting property, DSC, FTIR, XRD, and molecular weight. As cold plasma contains highly reactive species and free radicals, it is expected to cause noticeable modifications in the attributes of treated starch. There has been a significant reduction (p < 0.05) in turbidity value by 38.97% and pH value of starch from 6.49 to 4.05. Plasma-treated samples produced clearer pastes with higher stability over storage time. Cold plasma treatment also led to an increase in the ζ potential. However, there has been no significant change in the water activity and oil-binding capacity of the starch. Reducing sugar content, average molecular weight, degree of polymerization, pasting property, XRD, and FTIR data confirmed that cross-linking takes place in samples treated at lower voltages and lesser time followed by depolymerization occurring in harshly treated plasma samples. The study thus points out the possible use of cold plasma for starch modification to produce starches with altered properties.

Dynamics of Phyllosphere Microbiota and Chemical Parameters at Various Growth Stages and Their Contribution to Anaerobic Fermentation of Pennisetum giganteum.

This work evaluated the dynamic changes of phyllosphere microbiota and chemical parameters at various growth stages of Pennisetum giganteum and their effects on the bacterial community, cooccurrence networks, and functional properties during anaerobic fermentation. P. giganteum was collected at two growth stages (early vegetative stage [PA] and late vegetative stage [PB]) and was naturally fermented (NPA and NPB) for 1, 3, 7, 15, 30, and 60 days, respectively. At each time point, NPA or NPB was randomly sampled for the analysis of chemical composition, fermentation parameter, and microbial number. In addition, the fresh, 3-day, and 60-day NPA and NPB were subjected to high-throughput sequencing and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional prediction analyses. Growth stage obviously affected the phyllosphere microbiota and chemical parameters of P. giganteum. After 60 days of fermentation, NPB had a higher lactic acid concentration and ratio of lactic acid to acetic acid but a lower pH value and ammonia nitrogen concentration than NPA. Weissella and Enterobacter were dominant in 3-day NPA and Weissella was dominant in 3-day NPB, while Lactobacillus was the most abundant genus in both 60-day NPA and NPB. The complexity of bacterial cooccurrence networks in the phyllosphere decreased with P. giganteum growth. The ensiling process further decreased the complexity of bacterial networks, with the simplest bacterial correlation structures in NPB. There were great differences in the KEGG functional profiles of PA and PB. Ensiling promoted the metabolism of lipid, cofactors, vitamins, energy, and amino acids but suppressed the metabolism of carbohydrates and nucleotides. Storage time had a greater influence than growth stage on bacterial community diversity, cooccurrence networks, and functional profiles of P. giganteum silage. Differences in bacterial diversity and functionality of P. giganteum silage caused by growth stage appear to be offset by long-term storage. IMPORTANCE The phyllosphere microbiota consists of various and complex microbes, including bacteria with crucial relevance to the quality and safety of fermented food and feed. It initially derives from soil and becomes specific to its host after interaction with plants and climate. Bacteria associated with the phyllosphere are highly abundant and diverse, but we know little about their succession. Here, the phyllospheric microbiota structure was analyzed within the growth of P. giganteum. We also evaluated the effects of phyllosphere microbiota and chemical parameter changes on the anaerobic fermentation of P. giganteum. We observed remarkable differences in bacterial diversity, cooccurrence, and functionality of P. giganteum at various growth stages and storage times. The obtained results are important for understanding the fermentation mechanism and may contribute to high-efficient production without additional cost.

Reduction in the cadmium (Cd) accumulation and toxicity in pearl millet (Pennisetum glaucum L.) by regulating physio-biochemical and antioxidant defense system via soil and foliar application of melatonin.

Cadmium (Cd) is among the toxic pollutants that harms the both animals and plants. The natural antioxidant, melatonin can improve Cd-stress tolerance but its potential role in reducing Cd stress and resilience mechanisms in pearl millet (Pennisetum glaucum L.) is remain unclear. The present study suggests that Cd causes severe oxidative damage by decreasing photosynthesis, and increasing reactive oxygen species (ROS), malondialdehyde content (MDA), and Cd content in different parts of pearl millet. However, exogenous melatonin (soil application and foliar treatment) mitigated the Cd toxicity and enhanced the growth, antioxidant defense system, and differentially regulated the expression of antioxidant-responsive genes i. e superoxide dismutase SOD-[Fe] 2, Fe-superoxide dismutase, Peroxiredoxin 2C, and L-ascorbate peroxidase-6. The results showed that foliar melatonin at F-200/50 significantly increased the plant height, chlorophyll a, b, a+b and carotenoids by 128%, 121%, 150%, 122%, and 69% over the Cd treatment, respectively. The soil and foliar melatonin at S-100/50 and F-100/50 reduced the ROS by 36%, and 44%, and MDA by 42% and 51% over the Cd treatment, respectively. Moreover, F200/50 significantly boosted the activities of antioxidant enzymes i. e SOD by 141%, CAT 298%, POD 117%, and APX 155% over the Cd treatment. Similarly, a significant reduction in Cd content in root, stem, and leaf was found on exposure to higher concentrations of exogenous melatonin. These findings suggest that exogenous melatonin may significantly and differentially improve the tolerance to Cd stress in crop plants. However, field applications, type of plant species, concentration of dose, and type of stress may vary with the degree of tolerance in crop plants.

Silicon-mediated regulation of cadmium transport and activation of antioxidant defense system enhances Pennisetum glaucum resistance to cadmium stress.

Pennisetum glaucum is an important forage grass for livestock. However, the large accumulation of cadmium (Cd) in plant tissues increases the risk of heavy metals entering the food chain in Cd-contaminated soils. Silicon (Si) can inhibit cadmium (Cd) uptake and enhance tolerance of plant to Cd toxicity, but whether and how Si alleviates Cd toxicity in grass and the underlying mechanisms are unclear. The present study explored the differential mechanisms of silicon-induced Cd transport in apoplast and symplast, Cd distribution in root tissue and antioxidant defense system in P. glaucum under Cd stress through hydroponic and pot experiments. The present results showed that exogenous Si supply significantly reduced Cd concentrations in apoplast and symplast; Si treatment increased monosilicic acid concentration in apoplast and symplast of the roots and shoots under Cd stress. Elemental analysis of root microdomains showed that Si treatment increased the distribution of Cd and Si in the endodermis by 42.6% and 14.0%, respectively. Si alleviated the adverse influences of Cd on plant growth, which were manifested in root morphological traits and root activity. In addition, Si addition significantly increased the activities of catalase and superoxide dismutase by 37.0% and 72.7%, and improved the efficiency of the ascorbate-glutathione cycle in Cd-stress shoots. Furthermore, Si significantly reduced the contents of hydrogen peroxide and superoxide anion in Cd-stressed shoots by 16.6% and 48.7%, respectively. These findings demonstrate that Si enhances the resistance of P. glaucum to Cd stress through regulating Cd transport pathways and activating antioxidant defense systems.

Physiological and transcriptome analyses demonstrate the silver nanoparticles mediated alleviation of salt stress in pearl millet (Pennisetum glaucum L).

Pearl millet (Pennisetum glaucum L.) is a highly nutritive-value summer-annual forage crop used for hay, silage, grazing, and green chop. However, abiotic stresses including salinity negatively affect its growth and productivity. Furthermore, the nanotechnology is attaining greater consideration to reduce the impact of environmental stresses in plants. In the present study, transcriptome responses of silver nanoparticles (AgNPs) in pearl millet under salinity were investigated. The treatments were given as Control, NaCl (250 mM), AgNPs (20 mg/L), and NaCl + AgNPs to pearl millet seedlings after thirteen days of seed sowing. After 1 h of given treatments, leaf samples were collected and subjected to physio-chemical examination and transcriptome analyses. Salt stress increased the hydrogen peroxide (H2O2), malondialdehyde (MDA) content, and proline as compared to other treatments. In addition, the combined applications of NaCl + AgNPs ameliorated the oxidative damage by increasing antioxidant enzymes activities including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). Furthermore, RNA sequencing data showed 6016 commonly annotated Differentially Expressed Transcripts (DETs) among various treated combinations. Among them, 427 transcripts were upregulated, and 136 transcripts were downregulated at nanoparticles vs control, 1469 upregulated and 1182 downregulated at salt vs control, 494 upregulated and 231 downregulated at salt + nanoparticles vs control, 783 upregulated and 523 downregulated at nanoparticles vs salt. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that Mitogen-activated protein kinase (MAPK) signaling pathway, biosynthesis of secondary metabolites, and plant hormonal signal transduction pathway were the enriched among all identified pathways. In addition, Reverse transcription quantitative real-time polymerase chain reaction (qRT-PCR) showed that salinity up regulated the relative expression of DETs in pearl millet while, AgNPs optimized their expression that are associated with various molecular and metabolic functions. Overall, AgNPs treatments effectively improved the morphology, physiology, biochemistry, and gene expression pattern under salinity which could be attributed to positive impacts of AgNPs on pearl millet.

Pennisetum glaucum Protein Extract Protects RBC, Liver, Kidney, Small Intestine from Oxidative Damage and Exhibits Anticoagulant, Antiplatelet Activity.

High level of exogenous ROS in the circulation affects RBC membrane integrity which facilitates the generation of endogenous RBC ROS, implicated in series of physiological changes primarily associated with thrombosis and vital tissue damage. Although, Pennisetum glaucum (pearl millet) stores abundance of proteins, their therapeutic potential is least explored. Thus, the purpose of this study is to examine the role of Pennisetum Glaucum Protein Extract (PGE) on oxidative stress induced cell/tissue damage and thrombosis.In this investigation, protein characterization was done by using SDS-PAGE, Native-PAGE, PAS-staining and HPLC. In-vitro oxidative stress was induced in RBC using sodium nitrite. While, in-vivo oxidative stress was induced in experimental rats using diclofenac. Stress markers and biochemical parameters were evaluated. Role of PGE on thrombosis was assessed by using, in-vitro plasma recalcification time, activated partial thromboplastin time, prothrombin time, mouse tail bleeding time (In-vivo) and platelet aggregation.PGE revealed varied range of molecular weight proteins on SDS-PAGE. PGE normalized the sodium nitrite induced oxidative damage of RBC and diclofenac induced oxidative damage in liver, kidney and small intestine. PGE exhibited anticoagulant effect by increasing the coagulation time of both PRP and PPP and mouse tail bleeding time. Furthermore, PGE prolonged the clotting time of only APTT but did not affect PT. PGE inhibited agonists ADP and epinephrine induced platelet aggregation.Our findings suggest, PGE could be a better contender in the management of oxidative stress and its associated diseases. ABBREVIATIONS: PGEPennisetum Glaucum protein ExtractAPPTActivated Partial Thromboplastin TimePTProthrombin TimeROSReactive Oxygen SpeciesPRPPlatelet Rich PlasmaPPPPlatelet Poor PlasmaSDS-PAGESodium Dodecyl Sulfate-Polyacrylamide Gel ElectrophoresisPASPeriodic Acid-schiff StainingODOptical DensityINRInternational Normalized RatioPBSPhosphate Buffered SalineSODSuperoxide DismutaseTCATrichloro Acetatic AcidDTNBDi-Thio-bis-NitroBenzoic acidSGOTSerum Glutamate Oxaloacetate TransaminaseSGPTSerum Glutamate Pyruvate TransaminaseALPAlkaline PhosphataseDFCDiclofenacSylSilymarinMEDMinimum Edema DoseMHDMinimum Hemorrhagic Dose.

A Review of the Potential Consequences of Pearl Millet (Pennisetum glaucum) for Diabetes Mellitus and Other Biomedical Applications.

Diabetes mellitus has become a troublesome and increasingly widespread condition. Treatment strategies for diabetes prevention in high-risk as well as in affected individuals are largely attributed to improvements in lifestyle and dietary control. Therefore, it is important to understand the nutritional factors to be used in dietary intervention. A decreased risk of diabetes is associated with daily intake of millet-based foods. Pearl millet is a highly nutritious grain, nutritionally comparable and even superior in calories, protein, vitamins, and minerals to other large cereals, although its intake is confined to lower income segments of society. Pearl millet contains phenolic compounds which possess antidiabetic activity. Thus, it can be used to prepare a variety of food products for diabetes mellitus. Moreover, it also has many health benefits, including combating diabetes mellitus, cancer, cardiovascular conditions, decreasing tumour occurrence, lowering blood pressure, heart disease risk, cholesterol, and fat absorption rate. Therefore, the current review addresses the role of pearl millet in managing diabetes.

Expression of a Pennisetum glaucum gene DREB2A confers enhanced heat, drought and salinity tolerance in transgenic Arabidopsis.

BACKGROUND: Pearl millet (Pennisetum glaucum) is an essential cereal crop, whose growth and yield are not impacted by abiotic stresses, such as drought, heat, and cold. The DREB transcription factors (TF) are some of the largest groups of TFs in plants and play varied roles in plant stress response and signal transduction. METHODS AND RESULTS: In the present study, PgDREB2A gene encoding a DREB transcription factor in pearl millet was functionally characterized in Arabidopsis. DREB2A proteins contain a conserved domain that binds toethylene responsive element binding factors. Three different T1 transgenic lines overexpressing PgDREB2A gene were identified by Southern blot. Quantitative real-time polymerase chain reaction exhibited that PgDREB2A could be induced under drought conditions. As compared with the control, PgDREB2A overexpressing transgenic Arabidopsis showed increased rate of seed germination and root growth in transgenic lines under higher concentrations of mannitol, NaCl, ABA, heat and cold stress. Additionally, PgDREB2A transgenic lines showed enhanced durability after rehydration and tolerance to drought and salt stress was augmented with increased proline and reduced MDA build-up and diminishing water loss. CONCLUSIONS: Results from this study suggested that PgDREB2A as a transcription factor may improve endurance to various abiotic stresses and can be employed for developing crops tolerant to abiotic stresses.

Pearl millet starch-based nanocomposite films reinforced with Kudzu cellulose nanocrystals and essential oil: Effect on functionality and biodegradability.

This paper documents the preparation of three biopolymer films: 1) pearl millet starch (PMS) films, 2) PMS films reinforced with cellulose nanocrystals (CNCs), and 3) PMS films reinforced with CNCs stabilized Pickering emulsion of clove bud oil (CBO) and a comparison of their mechanical and water barrier properties and biodegradation behavior in soil. Reinforcing PMS films with Kudzu CNCs/CBO significantly increased tensile strength (from 3.9 to 16.7 MPa) and Young's modulus (from 90 to 376 MPa) but reduced the elongation (54.2 to 30 %) at the break of nanocomposite films. Also, the water vapor permeability of nanocomposite films decreased (from 9.60 to 7.25 × 10-10gm-1s- 1Pa-1) with the incorporation of Kudzu CNCs/CBO. The fastest biodegradation was observed for PMS films (98% in 15 days), followed by PMS films reinforced with Kudzu CNCs (96% in 18 days), followed by PMS films reinforced with Kudzu CNCs stabilized Pickering emulsions (94% in 21 days). The morphological analysis found hyphae-like structure formation due to microbial action, which increased over time. In general, all three biopolymer films showed good biodegradation behavior, and they all degraded between 15 and 21 days, suggesting that starch-based films reinforced with Kudzu CNCs provide a technique for the production of biodegradable packaging material.

Productivity and Quality of Pakchong-1 Hybrid Grass (Pennisetum purpureum × Pennisetum americanum) at Different Harvesting Ages and Fertilizer Levels.

<b>Background and Objectives:</b> The main feed for ruminants is forage, therefore it is necessary to need forage with high productivity and high nutritional content. One type of forage with very high productivity and high nutritional content is Pakchong grass 1. This study aims to determine the productivity of Pakchong 1 grass at different harvesting ages and levels of fertilizer. <b>Materials and Methods:</b> This study was carried out at the Department of Animal Husbandry, Faculty of Agriculture, University of Lampung. This research method was experimental with a completely randomized design with a 4×3 factorial pattern, with 3 replications. The first factor is harvesting age that consisting of 4 levels each: P₁ = 40 days, P₂ = 50 days, P₃ = 60 days and P₄ = 70 days. The second factor was the level of fertilizer use from the three treatments, each: J₁ = Low dose (consisting of 50 kg urea ha¹, 25 kg TSP ha¹ and 25 kg KCl ha¹), J₂ = Moderate dose (consisting of 100 kg urea ha¹, 50 kg TSP ha¹ and 50 kg KCl ha¹), J₃ = High dose (consisting of 200 kg urea ha¹, 100 kg TSP ha¹ and 100 kg KCL ha¹). Based on ANOVA, it showed that there was no significant interaction between the treatment on all parameters (p>0.05). <b>Results:</b> The treatment of harvesting age also significantly affected the grass stem leaf ratio (p<0.05). Crude protein content and neutral detergent fiber (NDF) were also affected by the age of the cut (p<0.05). <b>Conclusion:</b> It was observed that there was no interaction between a dose of fertilizer and harvesting age on all parameters. There was no significant also on dose fertilizer treatment. Meanwhile, significant results on harvesting age on the parameter of biomass production, leaf-stem ratio, crude protein content and NDF content.

Plant growth-promoting rhizobacteria Shewanella putrefaciens and Cronobacter dublinensis enhance drought tolerance of pearl millet by modulating hormones and stress-responsive genes.

Drought is a major abiotic stress that affects crop productivity. Endophytic bacteria have been found to alleviate the adverse effects of drought on plants. In the present study, we evaluated the effects of two endophytic bacteria Shewanella putrefaciens strain MCL-1 and Cronobacter dublinensis strain MKS-1 on pearl millet (Pennisetum glaucum (L.) R. Br.) under drought stress conditions. Pearl millet plants were grown under three water levels: field capacity (FC), mild drought stress (MD), and severe drought stress (SD). The effects of inoculation on plant growth, physiological attributes, phytohormone content, and drought stress-responsive genes were assessed. The inoculation of pearl millet seeds with endophytes significantly improved shoot and root dry weight and root architecture of plants grown under FC and drought stress conditions. There was a significant increase in relative water content and proline accumulation in the inoculated plants. Among the phytohormones analyzed, the content of ABA and IAA was significantly higher in endophyte-treated plants under all moisture regimes than in uninoculated plants. C. dublinensis-inoculated plants had higher GA content than uninoculated plants under all moisture regimes. The expression level of genes involved in phytohormone biosynthesis (SbNCED, SbGA20oX, and SbYUC) and coding drought-responsive transcription factors (SbAP2, SbSNAC1 and PgDREB2A) was significantly higher under SD in endophyte-inoculated plants than in uninoculated plants. Thus, these endophytic bacteria presumably enhanced the tolerance of pearl millet to drought stress by modulating root growth, plant hormones, physiology and the expression of genes involved in drought tolerance.

Cultivated and wild pearl millet display contrasting patterns of abundance and co-occurrence in their root mycobiome.

Fungal communities associated with roots play a key role in nutrient uptake and in mitigating the abiotic and biotic stress of their host. In this study, we characterized the roots mycobiome of wild and cultivated pearl millet [Pennisetum glaucum (L.) R. Br., synonym: Cenchrus americanus (L.) Morrone] in three agro-ecological areas of Senegal following a rainfall gradient. We hypothesized that wild pearl millet could serve as a reservoir of endophytes for cultivated pearl millet. We therefore analyzed the soil factors influencing fungal community structure and whether cultivated and wild millet shared the same fungal communities. The fungal communities associated with pearl millet were significantly structured according to sites and plant type (wild vs cultivated). Besides, soil pH and phosphorus were the main factors influencing the fungal community structure. We observed a higher fungal diversity in cultivated compared to wild pearl millet. Interestingly, we detected higher relative abundance of putative pathotrophs, especially plant pathogen, in cultivated than in wild millet in semi-arid and semi-humid zones, and higher relative abundance of saprotrophs in wild millet in arid and semi-humid zones. A network analysis based on taxa co-occurrence patterns in the core mycobiome revealed that cultivated millet and wild relatives had dissimilar groups of hub taxa. The identification of the core mycobiome and hub taxa of cultivated and wild pearl millet could be an important step in developing microbiome engineering approaches for more sustainable management practices in pearl millet agroecosystems.

Stage specific comparative transcriptomic analysis to reveal gene networks regulating iron and zinc content in pearl millet [Pennisetum glaucum (L.) R. Br.].

Pearl millet is an important staple food crop of poor people and excels all other cereals due to its unique features of resilience to adverse climatic conditions. It is rich in micronutrients like iron and zinc and amenable for focused breeding for these micronutrients along with high yield. Hence, this is a key to alleviate malnutrition and ensure nutritional security. This study was conducted to identify and validate candidate genes governing grain iron and zinc content enabling the desired modifications in the genotypes. Transcriptome sequencing using ION S5 Next Generation Sequencer generated 43.5 million sequence reads resulting in 83,721 transcripts with N50 of 597 bp and 84.35% of transcripts matched with the pearl millet genome assembly. The genotypes having high iron and zinc showed differential gene expression during different stages. Of which, 155 were up-regulated and 251 were down-regulated while during flowering stage and milking stage 349 and 378 transcripts were differentially expressed, respectively. Gene annotation and GO term showed the presence of transcripts involved in metabolic activities associated with uptake and transport of iron and zinc. Information generated will help in gaining insights into iron and zinc metabolism and develop genotypes with high yield, grain iron and zinc content.

Genome-wide miRNAs profiles of pearl millet under contrasting high vapor pressure deficit reveal their functional roles in drought stress adaptations.

Pearl millet (Pennisetum glaucum [L.] R. Br.) is an important crop capable of growing in harsh and marginal environments, with the highest degree of tolerance to drought and heat stresses among cereals. Diverse germplasm of pearl millet shows a significant phenotypic variation in response to abiotic stresses, making it a unique model to study the mechanisms responsible for stress mitigation. The present study focuses on identifying the physiological response of two pearl millet high-resolution cross (HRC) genotypes, ICMR 1122 and ICMR 1152, in response to low and high vapor pressure deficit (VPD). Under high VPD conditions, ICMR 1152 exhibited a lower transpiration rate (Tr), higher transpiration efficiency, and lower root sap exudation than ICMR 1122. Further, Pg-miRNAs expressed in the contrasting genotypes under low and high VPD conditions were identified by deep sequencing analysis. A total of 116 known and 61 novel Pg-miRNAs were identified from ICMR 1152, while 26 known and six novel Pg-miRNAs were identified from ICMR 1122 genotypes, respectively. While Pg-miR165, 168, 170, and 319 families exhibited significant differential expression under low and high VPD conditions in both genotypes, ICMR 1152 showed abundant expression of Pg-miR167, Pg-miR172, Pg-miR396 Pg-miR399, Pg-miR862, Pg-miR868, Pg-miR950, Pg-miR5054, and Pg-miR7527 indicating their direct and indirect role in root physiology and abiotic stress responses. Drought responsive Pg-miRNA targets showed upregulation in response to high VPD stress, further narrowing down the miRNAs involved in regulation of drought tolerance in pearl millet.