Plant Growth Research Articles

Automatic Localization of Soybean Seedlings Based on Crop Signaling and Multi-View Imaging

Soybean is grown worldwide for its high protein and oil content. Weeds compete fiercely for resources, which affects soybean yields. Because of the progressive enhancement of weed resistance to herbicides and the quickly increasing cost of manual weeding, mechanical weed control is becoming the preferred method of weed control. Mechanical weed control finds it difficult to remove intra-row weeds due to the lack of rapid and precise weed/soybean detection and location technology. Rhodamine B (Rh-B) is a systemic crop compound that can be absorbed by soybeans which fluoresces under a specific excitation light. The purpose of this study is to combine systemic crop compounds and computer vision technology for the identification and localization of soybeans in the field. The fluorescence distribution properties of systemic crop compounds in soybeans and their effects on plant growth were explored. The fluorescence was mainly concentrated in soybean cotyledons treated with Rh-B. After a comparison of soybean seedlings treated with nine groups of rhodamine B solutions at different concentrations ranging from 0 to 1440 ppm, the soybeans treated with 180 ppm Rh-B for 24 h received the recommended dosage, resulting in significant fluorescence that did not affect crop growth. Increasing the Rh-B concentration reduced crop biomass, while prolonged treatment times reduced seed germination. The fluorescence produced lasted for 20 days, ensuring a stable signal in the early stages of growth. Additionally, a precise inter-row soybean plant location system based on a fluorescence imaging system with a 96.7% identification accuracy, determined on 300 datasets, was proposed. This article further confirms the potential of crop signaling technology to assist machines in achieving crop identification and localization in the field.

Genome-Wide Identification of the Pectate Lyase Gene Family in Potato and Expression Analysis under Salt Stress

Pectin is a structural polysaccharide and a major component of plant cell walls. Pectate lyases are a class of enzymes that degrade demethylated pectin by cleaving the α-1,4-glycosidic bond, and they play an important role in plant growth and development. Currently, little is known about the PL gene family members and their involvement in salt stress in potato. In this study, we utilized bioinformatics to identify members of the potato pectate lyase gene family and analyzed their gene and amino acid sequence characteristics. The results showed that a total of 27 members of the pectate lyase gene family were identified in potato. Phylogenetic tree analysis revealed that these genes were divided into eight groups. Analysis of their promoters indicated that several members’ promoter regions contained a significant number of hormone and stress response elements. Further, we found that several members responded positively to salt treatment under single salt and mixed salt stress. Since StPL18 exhibited a consistent expression pattern under both single and mixed salt stress conditions, its subcellular localization was determined. The results indicated that StPL18 is localized in the endoplasmic reticulum membrane. The results will establish a foundation for analyzing the functions of potato pectate lyase family members and their expression under salt stress.

Precision Phenotyping of Wild Rocket (Diplotaxis tenuifolia) to Determine Morpho-Physiological Responses under Increasing Drought Stress Levels Using the PlantEye Multispectral 3D System

Precision Phenotyping of Wild Rocket (Diplotaxis tenuifolia) to Determine Morpho-Physiological Responses under Increasing Drought Stress Levels Using the PlantEye Multispectral 3D System

Case study: reducing heating energy consumption in a high tunnel greenhouse with renewable energy and microclimate control by bench-top root-zone heating, bench covers, and under-bench insulation

Appalachian State University's Nexus project designed an efficient greenhouse heating system that integrated renewable energy and root zone heating technology to reduce the greenhouse heating energy burden on local farmers and installed it at local cooperative farms. This study analyzed 5 years of data from 2018 to 2022 to investigate the energy savings and microclimate control effectiveness of the Nexus heating system installed at Springhouse Farm in North Carolina, USA. By varying bench cover materials, bottom insulation, and the number of loops of root zone tubing, the different soil temperatures required for plant types and growth stages were achieved with a single temperature controller. A root zone heating fluid of 32.2 ℃ satisfactorily maintained the germination soil between 20 and 25 ℃ in March 2019 with an average outside temperature of 4.8 ℃ and an average low temperature of − 0.4 ℃. Growing soil maintained an average temperature of 15 ℃ with bottom insulation and an average of 11–12 ℃ without bottom insulation. Compared to the conventional heating system (a forced-air propane unit heater alone), weather-adjusted propane consumption (propane usage divided by heating degree days) was reduced by 65% with the Nexus system alone and 45% with the Nexus system and unit heater together. It shows that the Nexus system has significantly reduced greenhouse heating energy consumption and maintained productive conditions. The renewable energy fraction ranged only 9–13% of the total thermal energy used due to the high inlet temperature entering the solar thermal collector. This can be improved by separating the heat storage and backup heat source.

The effect of foliar application of plant growth regulators on functional and qualitative characteristics of wheat (Triticum aestivum L.) under salinity and drought stress conditions

This study aimed to investigate the effect of salinity and water stress on the physiological and functional characteristics of winter wheat (Triticum aestivum L.) under the foliar application of plant growth regulators (PGRs). The experiment was carried out as a split plot based on a randomized complete block design with three replications in two environments. In each environment, water stress at two irrigation levels (after 90 and 120 mm of pan evaporation) and with two EC of 1.5 and 10 dS/m in the main plots and spraying of PGRs including salicylic acid (SA), gibberellic acid (GA3), and cytokinins (CK) (purine) content with a concentration of 100 ppm and the control treatment (spraying solution with normal water) were placed in subplots. Results indicated that all treatments caused significant increases in functional and qualitative characteristics and yield of Triticum aestivum L. The saline environment and irrigation level after 120 mm of pan evaporation caused a reduction in grain yield in all traits except for seed proline, seed nitrogen content, and seed protein content. Also, the combined foliar application of GA3 + CK + SA increased yield in most traits. The highest RWC of flag leaves was observed in the foliar application of GA3 + SA (3.36 kg/ha) and then in the foliar application of GA3 + SA + CK (57.87 kg/ha). GA3 interacts with PGR spraying to balance another development under saline and non-saline conditions.

Restoration of the soil fertility under Cr(VI) and artificial drought condition by the utilization of plant growth-promoting Bacillus spp. SSAU2.

The study explores the potential of an indigenous halo-tolerant microbe identified as Bacillus spp. SSAU-2 in enhancing soil fertility and promoting plant growth for sustainable agricultural practices under the influence of multiple abiotic stresses such as Cr(VI), high salinity, and artificial drought condition. The study investigated various factors influencing IAA synthesis by SSAU-2, such as pH (5 to 11), salinity (10 to 50g/L), tryptophan concentration (0.5 to 1%), carbon (mannitol mand lactose), and nitrogen sources (peptone and tryptone). The highest IAA concentration was observed at pH 10 (1.695mg/ml) and pH 11 (0.782mg/ml). IAA synthesis was optimized at a salinity level of 30g/l, with lower and higher salinity levels resulting in decreased IAA concentrations. Notably, the presence of mannitol and lactose significantly augmented IAA synthesis, while glucose and sucrose had inhibitory effects. Furthermore, peptone and tryptone played a pivotal role in enhancing IAA synthesis, while ammonium chloride exerted an inhibitory influence. SSAU-2 showed a diverse array of capabilities, including the synthesis of gibberellins, extracellular polymeric substances, siderophores, and hydrogen cyanide along with nitrogen fixation and ammonia production. The microbe could efficiently tolerate 45% PEG-6000 concentration and effectively produce IAA in 15% PEG concentration. It could also tolerate high concentration of Cr(VI) and synthesize IAA even in 50ppm Cr(VI). The findings of this study provide valuable insights into harnessing the potential of indigenous microorganisms to promote plant growth, enhance soil fertility, and establish sustainable agricultural practices essential for restoring the health of ecosystems.

Deciphering Nature’s Secret of Seaweed Extract as a Biostimulant on Horticultural Crops: A Review

Seaweed extracts have gained significant attention in horticultural practices due to their diverse range of beneficial effects on plant growth, development, and stress tolerance. The presence of antioxidants and Osm-protectants in seaweed extracts helps mitigate oxidative damage and maintain cellular integrity under adverse conditions. It also holds great promise as a valuable input in horticultural systems, offering a range of benefits including enhanced soil health, and sustainability. This review aims to summarize and analyze the benefits of seaweed extract application on horticultural crops. The extracts derived from seaweed are rich in essential nutrients which are available from through which plants can absorb easily and promote growth. It also contains numerous bioactive compounds including cytokinins, auxins, gibberellins, and betaines, which act as plant growth regulators. The application of seaweed extracts can induce systemic acquired resistance (SAR) in plants, triggering defense mechanisms against pathogens and pests, which can reduce the need for synthetic pesticides and fungicides, promoting sustainable and environmentally friendly horticultural practices. In addition to its direct effects on plants, seaweed extract enhances soil health and microbial activity. It serves as a natural biostimulant, promoting beneficial microbial populations in the rhizosphere, which facilitate nutrient uptake and cycling. Moreover, the humic substances present in seaweed extract contribute to soil structure improvement, water retention, and nutrient availability, fostering a conducive environment for plant growth.

Growth, dry matter and production components of cotton under phosphorus split application strategies

Compared with single application, the split application of phosphorus during sowing can enhance the efficiency of phosphate fertilization. In view of this, this study aimed to evaluate the effect of phosphorus split application on the growth, dry matter, and production components of the cotton plant. The experiment was carried out in a greenhouse at the Faculdade de Tecnologia of the Instituto Centro de Ensino Tecnológico Cariri (Fatec Cariri), located in the municipality of Juazeiro do Norte, Ceará. The experiment was arranged in a completely randomized design (DIC), with four replications. The treatments were composed of a combination of different phosphorus split application strategies: T1 = no phosphorus; T2 = application of 100 % of the phosphorus at sowing (conventional way); T3 = application of 50 % of the phosphorus at sowing and of 50 % at 35 days after sowing; T4 = application of 70 % of the phosphorus at sowing and of 30 % at 35 days after sowing; and T5 = application of 30 % of the phosphorus at sowing and of 70 % at 35 days after sowing. The following variables were evaluated: plant height; absolute growth rate; stem diameter; number of leaves; root dry matter; total dry matter; and number of flower buds and bolls. The treatments significantly influenced all the variables analyzed. Based on the outcomes, it was found that the split application of phosphorus did not improve the growth, dry matter and production components of the cotton plant compared to the single application.

Overexpression of NtEXPA7 promotes seedling growth and resistance to root-knot nematode in tobacco

Root-knot nematode (RKN) is one of the most damaging plant pathogen in the world. They exhibit a wide host range and cause serious crop losses. The cell wall, encasing every plant cell, plays a crucial role in defending of RKN invasion. Expansins are a group of cell wall proteins inducing cell wall loosening and extensibility. They are widely involved in the regulation of plant growth and the response to biotic and abiotic stresses. In this study, we have characterized the biological function of tobacco (Nicotiana tabacum) NtEXPA7, the homologue of Solyc08g080060.2 (SlEXPA18), of which the transcription level was significantly reduced in susceptible tomato upon RKN infection. The expression of NtEXPA7 was up-regulated after inoculation of RKNs. The NtEXPA7 protein resided in the cell wall. Overexpression of NtEXPA7 promoted the seedling growth of transgenic tobacco. Meanwhile the increased expression of NtEXPA7 was beneficial to enhance the resistance against RKNs. This study expands the understanding of biological role of expansin in coordinate plant growth and disease resistance.

Ecophysiology and Seedlings Nutrient Contents of Forest Species <i>Ricinodendron heudelotii </i>(Mull. Arg.) and <i>Cola acuminata </i>(P. Beauv.) Influenced by Biofertilizer and Salinity

<i>Ricinodendron heudelotii</i> and <i>Cola acuminata, </i>are important plants species whose exploitation became abusive over the years due to the high utilization of their fruits as Non-Timber Forest Products (NTFP). They face to multiple challenges: a recalcitrance of seeds and salinity that limits regeneration. Therefore, regeneration seems an appropriate corridor for domestication with the optimization of plant mycorrhizal symbiosis otherwise called arbuscular mycorrhizal fungi (AMF). But alongside this domestication can be added constraints due to salinity of the soils in coastal region. This justify the aim of this work which was to study dynamics and evaluate the effect of salinity and mycorrhizal biofertilizers on the <i>Ricinodendron heudelotii</i> and <i>Cola acuminata </i>seedlings. To undergo this purpose, data were collected in two villages (Kendje and Njombeng) in Mungo division, and assay were conducted in greenhouse at the Faculty of Science, University of Douala-Cameroon. In the field, the identification of species was assessed over an area of 1600 m² as well as the circumference of the trees, the individual number of <i>Ricinodendron heudelotii</i> and <i>Cola acuminata</i> among other species in order to assess their maturity and rarity in the forest. The second part was carried out in the greenhouse for the purpose of germination, obtaining seedlings and evaluating the effects of arbuscular mycorrhizal fungi (<i>Gisgaspora margarita</i>) as biofertilizers on the seedlings in saline conditions (0, 50, 100 and 200 mM of NaCl). Some parameters were determined on seedlings (plant growth, dry weight, distribution of ions in plant organs, chlorophyll and carotenoid content) over a period of twenty-six weeks. Globally <i>Cola acuminata </i>is more present in the forest (5.88%) than <i>Ricinodendron heudelotii</i> (1.47%) with average circumference of 105cm for both species. AMF-biofertilizer alleviates the deleterious effect of salt stress on plants growth parameters depending of concentration. Moreover, for those species, the distribution of Na<sup>+</sup> is more accumulated in the root’s plants unlike K<sup>+</sup> and P which are more concentrated in the leaves.

Genome-wide analysis of the GRAS gene family in white clover (Trifolium repens L.) provides insight into its critical role in response to cold stress

The GRAS transcription factor (TF) is a plant-specific regulator that plays a critical role in plant growth, development and response to various abiotic stresses. While the functions of many GRAS TFs have been extensively studied in numerous model plants with fully sequenced genomes, the GRAS TFs in white clover (Trifolium repens L.) remain elusive despite the sequencing of its genome. To bridge this knowledge gap, homologs of GRAS TFs from Arabidopsis were employed and subjected to a genome-wide blast against white clover proteins. This analysis identified and characterized 102 putative GRAS genes, designated as TrGRAS, based on the presence of GRAS domains in positive blast hits. Concurrently, an exploration of their gene structures, classification, evolutionary relationships and conservative motifs provided insights into the distinctive features of TrGRAS in white clover. Furthermore, gene duplication analysis revealed an expansion of TrGRAS genes in the PAT1 and LISCL subfamilies, indicating functional diversity within the white clover genome. Lastly, RNA-seq and quantitative reverse transcription-PCR (qRT-PCR) experiments confirmed their higher expression during the early or intermittent responses to cold stress, suggesting their potential and crucial roles in determining the cold tolerances of white clover. The analysis of TrGRAS genes, coupled with expression studies, contributes to the functional characterization of TrGRAS genes in white clover. This knowledge is pivotal for informing genetic improvement strategies in future breeding efforts aimed at enhancing cold tolerance in white clover.

Effect of foliar applications of aminolevulinic acid (bulk and nano-encapsulated) on bell pepper under heat stress

Plant growth and production can be adversely affected by high temperature stress, which is defined as an increase in temperature over a threshold level. 5-aminolevulinic acid (ALA) can be used as a beneficial growth regulator in agriculture, particularly for plants experiencing abiotic stress. The efficacy of exogenous two form ALA application (bulk and nanoencapsulated) was investigated in a factorial experiment based on a completely randomized block design with 12 replications. In this study, different temperatures (optimal temperature 25 °C, and high temperature 35 °C) and different ALA treatments were used (control, 1 mM of ALA, and 1 mM Nano-encapsulated N-ALA). The study revealed that elevated temperatures of 35 °C had an adverse impact on the majority of bell pepper growth characteristics. Nevertheless, the application of ALA and N-ALA significantly enhanced the growth characteristics under these conditions. In contrast to the conditions at 25 °C, the concentrations of potassium (K), proline, electrolyte leakage (EL), glucose, and fructose exhibited an increase at 35 °C. However, both forms of ALA were effective in mitigating these adverse effects. Comparatively, the control treatment showed elevated levels of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) enzymes, along with increased malondialdehyde (MDA) levels compared to the ALA treatment. The treatment with ALA resulted in the highest fresh weight and shoot length at 35 °C compared to N-ALA. Conversely, at the same temperature, N-ALA led to a 17 % increase in chlorophyll fluorescence and a 32 % increase in DPPH compared to ALA. In summary, the application of both ALA and Nano-encapsulated N-ALA effectively mitigates the adverse effects of exposure to 35 °C on bell pepper growth and biochemical parameters.

Seed osmopriming with polyethylene glycol (PEG) enhances seed germination and seedling physiological traits of Coronilla varia L. under water stress.

Water stress can adversely affect seed germination and plant growth. Seed osmopriming is a pre-sowing treatment in which seeds are soaked in osmotic solutions to undergo the first stage of germination prior to radicle protrusion. Seed osmopriming enhances germination performance under stressful environmental conditions, making it an effective method to improve plant resistance and yield. This study analyzed the effect of seed osmopriming with polyethylene glycol (PEG) on seed germination and physiological parameters of Coronilla varia L. Priming treatments using 10% to 30% PEG enhanced germination percentage, germination vigor, germination index, vitality index, and seedling mass and reduced the time to reach 50% germination (T50). The PEG concentration that led to better results was 10%. The content of soluble proteins (SP), proline (Pro), soluble sugars (SS), and malondialdehyde (MDA) in Coronilla varia L. seedlings increased with the severity of water stress. In addition, under water stress, electrolyte leakage rose, and peroxidase (POD) and superoxide dismutase (SOD) activities intensified, while catalase (CAT) activity increased at mild-to-moderate water stress but declined with more severe deficiency. The 10% PEG priming significantly improved germination percentage, germination vigor, germination index, vitality index, and time to 50% germination (T50) under water stress. Across the water stress gradient here tested (8 to 12% PEG), seed priming enhanced SP content, Pro content, and SOD activity in Coronilla varia L. seedlings compared to the unprimed treatments. Under 10% PEG-induced water stress, primed seedlings displayed a significantly lower MDA content and electrolyte leakage than their unprimed counterparts and exhibited significantly higher CAT and POD activities. However, under 12% PEG-induced water stress, differences in electrolyte leakage, CAT activity, and POD activity between primed and unprimed treatments were not significant. These findings suggest that PEG priming enhances the osmotic regulation and antioxidant capacity of Coronilla varia seedlings, facilitating seed germination and seedling growth and alleviating drought stress damage, albeit with reduced efficacy under severe water deficiency.

Crosstalk between brassinosteroids and other phytohormones during plant development and stress adaption.

Brassinosteroids (BRs) are a group of polyhydroxylated phytosterols that play essential roles in regulating plant growth and development as well as stress adaptation. It is worth noting that BRs do not function alone, but rather they crosstalk with other endogenous signaling molecules, including the phytohormones auxin, cytokinins (CKs), gibberellins (GAs), abscisic acid (ABA), ethylene (ET), jasmonates (JAs), salicylic acid (SA), and strigolactones (SLs), forming elaborate signaling networks to modulate plant growth and development. BRs interact with other phytohormones mainly by regulating each others' homeostasis, transport, or signaling pathway at the transcriptional and posttranslational levels. In this review, we focus our attention on current research progress in BR signal transduction and the crosstalk between BRs and other phytohormones.

An Efficient Indoor Nursery Controlled by IOT and Monitored by Android App.

Gardening is one of the greatest hobbies or mind relaxing activities for all age groups, which kindles them to make nursery management system. Nowadays also most of the nursery owners using a manual system to water and monitor their plants. There are many difficulties or challenges for nursery owners to take care of the plants growth, so that they need to check the moisture of the soil, monitor the air humidity and temperature, and others parameters. This paper offers a solution to combine the Internet of Things (IoT) system and Android apps to monitor the plant's growth with a real-time data monitoring and also provides the system control. In this paper, the sensors are used to sense the moisture of soil, check the air humidity and temperature, discover the light intensity and measure the soil temperature. This system allows nursery owners to monitor and control the irrigation system where they can water their plants using mobile application. The sensor checks the condition of the plant and updates the data in every one hour. Other than that, Indoor nursery often faces the issue of inadequate sunlight. Natural light coming through windows may not be as strong as outdoor sunlight, which is essential for photosynthesis. Therefore, this system offers a solution that allows nursery owners to control a specific light-emitting diode (LED) or UV LED to simulate sunlight. This ensures that plants receive the necessary light for photosynthesis and grow healthy. Growth of Plants contribute towards air purification providing fresher air to breathe.

Different roads, same destination: The shared future of plant ecophysiology and ecohydrology.

Terrestrial water fluxes are substantially mediated by vegetation, while the distribution, growth, health, and mortality of plants are strongly influenced by the availability of water. These interactions, playing out across multiple spatial and temporal scales, link the disciplines of plant ecophysiology and ecohydrology. Despite this connection, the disciplines have provided complementary, but largely independent, perspectives on the soil-plant-atmosphere continuum since their crystallization as modern scientific disciplines in the late 20th century. This review traces the development of the two disciplines, from their respective origins in engineering and ecology, their largely independent growth and maturation, and the eventual development of common conceptual and quantitative frameworks. This common ground has allowed explicit coupling of the disciplines to better understand plant function. Case studies both illuminate the limitations of the disciplines working in isolation, and reveal the exciting possibilities created by consilience between the disciplines. The histories of the two disciplines suggest opportunities for new advances will arise from sharing methodologies, working across multiple levels of complexity, and leveraging new observational technologies. Practically, these exchanges can be supported by creating shared scientific spaces. This review argues that consilience and collaboration are essential for robust and evidence-based predictions and policy responses under global change.

Assessing the bioaccumulation and translocation potential of vetiver grass for dioxins phytoremediation in Bien Hoa airbase, Viet Nam

Dioxins (PCDD/Fs) are well-known toxic organic pollutants that accumulate in the environment and the food chain, imposing a risk to human health and the ecosystem. Due to the use of dioxin-contaminated herbicides during the US-Vietnam War, there are several hotspots in Vietnam with very high levels of dioxins. Phytoremediation has been increasingly developed in recent decades because of its low cost and environmental-friendly aspect. Vetiver grass is a plant that can remediate both organic and inorganic agents. In this study, the uptake and translocation of dioxins in Vetiver grass (Chrysopogon zizanioides) from the dioxin-contaminated soil was investigated in a field experiment on the Bien Hoa airbase, Vietnam. An experimental area was divided into six plots, of which three were planted with Vetiver grass and three served as control plots, with the initial dioxin concentrations as following: FC2>FC3>FC1>FT2>FT3>FT1. Vetiver grass had grown well on the dioxin-contaminated soils, yielding high biomass and the level of dioxins in the roots of vetiver grass was positively correlated (r2 = 0.67; p<0.01) with its growth rate. During the first year of cultivation, Vetiver grass had the greatest capacity to efficiently accumulate dioxin. Accumulation occurs in the roots, with BAF>1 throughout the entire experiment period for FT3, and in the first year for FT1 and FT2. The dioxin translocation from the roots to the shoots was significantly lower than the BAF and less than one (TF<1), with the first and second sampling times having the highest values compared to the others. Dioxin concentrations do not provide a reliable indicator of its bioavailability but numerous other factors, such as physicochemical properties of the soil and microbes. Our study aims to contribute significant insights to capability of Vetiver grass to accumulate and translocate dioxins, hence the arsenal of dioxin remediation. Furthermore, we envisage translating our findings into practical applications in other areas, considering optimized planting techniques, growth conditions, and long-term sustainability.

Degradation of petroleum hydrocarbon contaminants by Rhodococcus erythropolis KB1 synergistic with alfalfa (Medicago sativa L.).

Petroleum hydrocarbons are a stubborn pollutant that is difficult to degrade globally, and plant-microbial degradation is the main way to solve this type of pollutant. In this study, the physiological and ecological responses of alfalfa to petroleum hydrocarbons in different concentrations of petroleum hydrocarbon-contaminated soil with KB1 (Rhodococcus erythropolis) were analyzed and determined by laboratory potting techniques. The growth of alfalfa (CK) and alfalfa with KB1 (JZ) in different concentrations of petroleum hydrocarbons contaminated soil was compared and analyzed. The results of the CK group showed that petroleum hydrocarbons could significantly affect the activity of alfalfa antioxidant enzyme system, inhibit the development of alfalfa roots and the normal growth of plants, especially in the high-concentration group. KB1 strain had the ability to produce IAA, form biofilm, fix nitrogen, produce betaine and ACC deaminase, and the addition of KB1 could improve the growth traits of alfalfa in the soil contaminated with different concentrations of petroleum hydrocarbons, the content of soluble sugars in roots, and the stress resistance and antioxidant enzyme activities of alfalfa. In addition, the degradation kinetics of the strain showed that the degradation rate of petroleum could reach 75.2% after soaking with KB1. Furthermore, KB1 can efficiently degrade petroleum hydrocarbons in advance and significantly alleviate the damage of high concentration of petroleum hydrocarbons to plant roots. The results showed that KB1 strains and alfalfa plants could effectively enhance the degradation of petroleum hydrocarbons, which provided new ideas for improving bioremediation strategies.

Actinomycetes as a Possible Source of Bioremediation of Heavy Metal Cadmium from Contaminated Soil

Annually, a significant volume of chemicals, encompassing fertilizers and pesticides, is administered to agricultural soils. Using pesticides and fertilizers, agricultural practices contribute to heavy metal Cadmium (Cd), Copper (Cu), Lead (Pb) and Zinc (Zn) pollution. Heavy metals and pesticides are high at the peak of ecological contaminants, presence of this has introduced grave risks to the health of the population and agronomics. Among heavy metals, cadmium (Cd) is recognized for its high mobility in various environmental settings. Cd has a deleterious effect on plant phenotypic, cytotoxicity (e.g., lowering chlorophyll concentration and limiting photosynthetic effectiveness), and metabolic activities (e.g., chlorosis and necrosis). Microbial bioremediation by using microorganisms is one of the secure, pure, cost operative and eco-friendly technology for decontaminating polluting sites as compared to physical and chemical techniques. Among microbes, Actinobacteria hold a paramount position, serving as key players in numerous biological processes, utilize toxins as carbon source and turn into high concentrations of pesticides, chemical complexes and heavy metals into commercially viable antibiotics, enzymes, proteins, and plant growth promoting hormones. This study is an effort to explore the potent cadmium resistance actinomycetes to reduce cadmium levels to enhance degradation. For this purpose, 53 actinomycetes strains were tested for heavy metal resistance and tolerance to Cadmium against different concentrations. After secondary screening Four potent isolate have the potential to grow at 1000 mg/L concentration of Cadmium in the medium. When they are able to grow on heavy metal containing media it could be beneficial for reduction and elimination of toxic metals from contaminated environment. When it comes to achieving a suitable level of metal tolerance, this potent powerful actinomycetes strain Streptomyces pactum have been identified to be promising.

Molecular identification and characterizations of rhizobacterial isolates collected from lentil rhizosphere of Indo-gangetic plains.

Plant growth promoting rhizobacteria (PGPR) are also known to colonize in the soil rhizosphere and prevent the development of other soil borne pathogens residing in the root surface. These microorganisms play a vital role in growth and development of the plant and also enhances the soil fertility by enriching the soil with different beneficial nutrients. This study was aimed at isolation of different rhizobacteria and their molecular characterization in search of efficient bacterial strains with multiple growth regulating activities. A total 36 bacteria were isolated from lentil root nodule as well as soil from different lentil growing fields with a view to screen/evaluate their plant growth promoting potential. Morphological characterization of isolated rhizobacterial candidates were done by observing the colonies on YEMA and nutrient agar media. Determination of CFU, Congo red test and gram staining tests were done to further screen them according to their morphology. All the isolates were then undergone molecular phylogenetic analysis using the partial sequences of the 16S rDNA. Based upon the Gram staining test, all the isolates were negative in gram reaction except six Bacillus isolates, PSB2 and AB3. Results of Ribosomal Database Project (RDP) and Basic Local Alignment Search Tool for Nucleotide Sequences (BLASTn) from 16S rDNA gene sequences showed that these isolates are genetically diverse. A total of 15 isolates of Rhizobium, 6 isolates of Bacillus, 3 isolates of Pseudomonas, 2 isolates of Phosphate Solubilizing Bacteria, 4 isolates of actinomycetes were identified by molecular sequencing of their 16S rDNA region and comparing them with the other isolates enlisted in the database of NCBI for the similarity percentage, query coverage. The purpose of the present study was to select native rhizosphere bacteria from the lentil nodule and soil of Lentil field and to evaluate their plant growth promoting potential as an alternative of chemical fertilizer for sustainable, environment friendly agriculture and assessment of their phylogenetic characterization.