Seed Germination Assay Research Articles

EVALUATION OF SULFURIC ACID, BARIUM CHLORIDE, AND SEED GERMINATION ASSAY METHODS AS EARLY PREGNANCY DETECTION INSTRUMENTS IN CATTLE

This study aims to validate and re-evaluate the use of H2SO4, BaCl2, and seed germination assay (SGA) methods to detect early pregnancy in cattle. Validation was carried out in order to find out the actual test performance value, which include accuracy, sensitivity, and specificity.Validation test was done by reacting the urine of pregnant and non-pregnant cattle populations with H2SO4 solution diluted at a ratio of 1 : 4, with 1% BaCl2 solution or through germination of mung bean seeds in Petri dishes. The results of this study indicated that the H2SO4 and BaCl2 methods have poor accuracy (21.88% and 28.13%) with the sensitivity of 81.82% and 100% and specificity of 9.43% and 13.21%, respectively. Meanwhile, the SGA method had a fairly good accuracy (74.55%) with sensitivity and specificity of 45.46% and 81.82%, respectively. Based on these results, the H2SO4, BaCl2, and SGA methods are not recommended for detection of early pregnancy in the field.

Decolourisation and detoxification of CI Direct Blue 201 textile dye by two fungal strains of genus Aspergillus

Two fungal strains capable of decolourisation of CI Direct Blue 201 textile dye were isolated from textile wastewater effluent sites in Sri Lanka and they were identified as Aspergillus aculeatus and Aspergillus nomius using 18s rRNA analysis. A. nomius and A. aculeatus showed 98 % decolourisation of CI Direct Blue 201 textile dye (50 mg/L) at 3rd day of incubation with the supplement of modified Kirk’s medium. Both fungal strains were found to be more effective for dye decolourisation at temperatures ranging from 24 ˚C to 36 ˚C. Further, it was found that the decolourisation potential increased at pH 5 and 10 under shaking condition (100 rpm) with the presence of glucose and nitrate as additional carbon and nitrogen sources. Seed germination assay showed less germination (22.2 ± 5.0 % and 10.0 ± 3.3 % for Oryza sativa and Vigna radiata, respectively) when seeds were exposed to the original dye in comparison to 100 % seed germination observed when exposed to fungal treated dye effluent, showing the detoxification of dye by the fungal isolates.

Biodegradation and biosorption of Reactive Red 120 dye by immobilized Pseudomonas guariconensis: Kinetic and toxicity study.

Reactive dyes are pernicious pollutants in textile effluent, which are to be treated passably before discharging into the environment. In the present study, a potential dye degrading bacterial strain Pseudomonas guariconensis was isolated from paddy rhizosphere and was characterized by 16S rRNA gene sequencing. The biodegradation ability of the strain was evaluated by time-based study with immobilized bacterial cells in calcium alginate biocarrier matrix and also with free cells. The results indicated that the strain exhibited maximum degradation of 91% when immobilized in the biocarrier matrix. The enzymatic study revealed the production of oxidoreductase enzymes. The degraded products were identified as 2-amino-3-phenylpropanoic acid and benzoquinone by gas chromatography-mass spectroscopy (GC-MS) analysis, and a degradative pathway was derived based on the enzymatic profile. A packed bed column was designed using P.guariconensis VITSAJ5 immobilized in calcium alginate beads as a biosorbent for the removal of Reactive Red 120. The immobilized bacterial cells exhibited 87% uptake of RR120, whereas the nonimmobilized bacterial cells exhibited a maximum uptake of 37%. The phytotoxicity analysis by seed germination assay revealed an enhanced plumule and radicle length, indicating the nontoxic byproducts after the treatment of Reactive Red 120 by VITSAJ5 compared to the untreated Reactive Red 120 solution. PRACTITIONER POINTS: Current study is the first report on Pseudomonas guariconensis capable of degrading reactive dyes (Reactive Red 120) It was observed that the degradation potential was maximum when cells were immobilized with Ca-Ag biocarrier matrix Breakdown metabolism of Reactive Red 120 was derived through pathway prediction Employing immobilized bacteria in a packed bed column found to possess a prominent biosorption ability on the matrix enhancing the degradation process Toxic reactive dye was converted into nontoxic compounds, evidenced by phytotoxicity studies.

Cell wall/vacuolar inhibitor of fructosidase 1 regulates ABA response and salt tolerance in Arabidopsis

ABSTRACTABA regulates abiotic stress tolerance in plants via activating/repressing gene expression. However, the functions of many ABA response genes remained unknown. C/VIFs are proteinaceous inhibitors of the CWI and VI invertases. We report here the involvement of C/VIF1 in regulating ABA response and salt tolerance in Arabidopsis. We found that the expression level of C/VIF1 was increased in response to ABA treatment. By using CRISPR/Cas9 gene editing, we generated transgene-free c/vif1 mutants. We also generated C/VIF1 overexpression plants by expressing C/VIF1 under the control of the 35S promoter. We examined ABA response of the 35S:C/VIF1 transgenic plants and the c/vif1 mutants by using seed germination and seedling greening assays, and found that the 35S:C/VIF1 transgenic plants showed an enhanced sensitivity to ABA treatment in both assays. On the other hand, the c/vif1 mutants showed slight enhanced tolerance to ABA only at the early stage of germination. We also found that salt tolerance was reduced in the 35S:C/VIF1 transgenic plants in seed germination assays, but slightly increased in the c/vif1 mutants. Taken together, our results suggest that C/VIF1 is an ABA response gene, and C/VIF1 is involved in the regulation of ABA response and salt tolerance in Arabidopsis.

AIW1 and AIW2, two ABA-induced WD40 repeat-containing transcription repressors function redundantly to regulate ABA and salt responses in Arabidopsis

ABSTRACT WDR proteins in plants regulate multiple aspects of plant growth and development, as well as plant responses to environmental stimuli. Here, we report the identification of AIW1 (ABA-induced WD40-repeat 1) and AIW2 as novel regulators of salt responses in Arabidopsis. RT-PCR results show that the expression of AIW1 and AIW2 were induced by ABA. Transfection assays in protoplasts show that AIW1 and AIW2 were nucleus proteins and functioned as transcription repressors. When overexpressed in Arabidopsis, AIW1 promoted root elongation, and reduced seedlings sensitivity to ABA. On the other hand, aiw1 aiw2 double mutants showed an increased sensitivity to ABA in seed germination assays. In addition, salt tolerance was reduced in the 35S:AIW1 transgenic plants in root elongation assays. Taken together, our results suggest that AIW1 and AIW2 are ABA-induced plant specific WD40 repeat-containing transcription repressors, and AIW1 and AIW2 function redundantly to regulate ABA and salt responses in Arabidopsis.

Appraisal of lignocellusoic biomass degrading potential of three earthworm species using vermireactor mediated with spent mushroom substrate: Compost quality, crystallinity, and microbial community structural analysis.

Spent mushroom substrate (SMS) is a recalcitrant lignocellulosic waste. Recycling of SMS through composting has been reported; however, the process is lengthy due to its complex biochemical composition. Although vermitechnology is known for its high efficiency, it has rarely been applied to recycle SMS. In this study, the qualitative value of vermicomposted SMS mediated by three earthworm species (i.e., Eisenia fetida, Eudrilus eugeniae, and Perionyx excavatus) was evaluated on the basis of nutrient availability, microbial activity, phospholipid fatty acid (PLFA) profiles, and seed germination assays. Degradation profiles of the lignocellulosic substrate in the vermireactors were assessed by monitoring the changes in crystallinity and distribution of functional groups using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy, respectively. Total organic carbon decreased by 1.4-3.5 folds with approximately 2.1-2.4 folds increase in nitrogen and phosphorus availability in all vermibeds. Interestingly, pH declined in the Eisenia and Eudrilus systems but increased in the Perionyx-vermibeds. XRD-derived crystallinity index was reduced significantly by 1.37 folds in Perionyx-vermicompost with concurrent microbial enrichment. Further, profuse abundance of vital functional groups (CO, NH, and OH) was clearly observed in the vermicompost with Perionyx followed by that with Eisenia. Moreover, PLFA illustrated significant variations in fatty acid distributions and microbial communities of the three vermicomposting systems. The seed germination assay showed that the germination index and relative root-shoot vigor of Perionyx-vermicompost treated seeds were 1.05-1.30 times greater than those of Eisenia and Eudrilus vermicompost treated ones. The results suggest that SMS degradability was affected by the growth of a healthy microbial community through vermicomposting.

Development of ABA Antagonists to Overcome ABA- and Low Temperature-Induced Inhibition of Seed Germination in Canola, Lentil, and Soybean

ABA antagonists have potential application as growth regulators to improve germination and seedling growth at low temperatures for oilseeds and pulses grown in regions with short seasons such as those in western Canada. Towards development of practical ABA antagonists, a series of 3′-substituted ABA analogs were synthesized and screened in seed germination assays in canola (Brassica napus), lentil (Lens culinaris), and soybean (Glycine max) at low temperature and in overcoming exogenous ABA. The most promising analog, ABA 1009, was selected for further germination testing of dose responses in canola, lentil, and soybean. Analog ABA 1009 at 100 µM was effective in overcoming ABA (10 µM)-induced inhibition for canola, lentil, and soybean germination at ambient temperature, and also promoted germination at low temperature for canola (5 °C).

Screening and characterization of actinomycetes isolated from soybean rhizosphere for promoting plant growth

Abstract. Fatmawati U, Meryandini A, Nawangsih AA, Wahyudi AT. 2019. Screening and characterization of actinomycetes isolated from soybean rhizosphere for promoting plant growth. Biodiversitas 20: 2970-2977. Actinomycetes which colonized plant rhizosphere has a vital role in improving plant growth by producing Indole-3-Acetic Acid (IAA). The aim of this study was to evaluate the potency of actinomycetes isolated from soybean rhizosphere as promoter agents for plant growth in vitro. Fifty actinomycetes isolates were successfully isolated from soybean rhizosphere. Based on the colorimetric methods, 35 isolates can produce IAA in various concentration, in the range of 0.46-30.6 mg/L. Seed germination assay using Ragdoll methods revealed that 26 isolates significantly promoted germination parameters, including the hypocotyl and the radicular length, the number of the lateral roots, and dry weight of the plant. Also, 14 from 26 isolates showed phosphate solubilizing activity in different phosphate-solubilizing index ranging from 1.25-2.62. Eight isolates were able to grow in N-free medium, indicating that these isolates have the ability in fixing nitrogen. Out of 23 from 26 isolates were detected to produce siderophore. All the tested isolates show chitinase production except ASR 55. Based on the observed parameters, it showed that there are four potential isolates (ASR 46, ASR 58, ASR 75 and ASR 76) as promising plant-growth promoters, phosphate solubilizer, nitrogen fixer, siderophore and chitinase producer. Based on the result of 16S rRNA sequence analysis, four potential isolates were identified as Streptomyces spp. in different taxa of strains and species.

Tuning of structural, optical and toxicological properties of Gd3+ doped Yb2O3 nanoparticles

Abstract The nanoparticles of Ytterbium oxide (Yb2O3) with spherical architectures have been synthesized by using hydrothermal procedure. The prepared Yb2O3 nanoparticles were further doped with Gd3+ ions for exploring the potential of the nanoparticles in terms of tuning the optical properties such as band gap. Here, we demonstrated that the dopant inside the nanoparticles affects the optical properties and show how it has a relevant consequence on the overall peak position of Yb2O3 as a function of dopant concentrations. We have also examined the crystallite changes in Yb2O3 nanoparticles by employing the X-ray peak profile analysis. The respective Williamson–Hall studies and size–strain plot were employed to study the individual roles of crystallite sizes and lattice strain over Yb2O3 nanoparticles as a function of Gd3+ ion doping. The factors including strain, stress and energy density value were computed for both bare and Gd3+ ion doped Yb2O3 nanoparticles. The toxicological profiling of bare and Gd3+ doped Yb2O3 nanoparticles were carried out by multiple assays including antibacterial, antifungal, seed germination assay and A. Cepa genotoxic studies. The results have demonstrated the excellent biocompatibility of prepared nanoparticles and signifying their potential applications in biomedical field.

Amelioration of Physico-Chemical Parameters and Phytotoxicity of Landfill Leachate by Microbial Degradation

Objective: To understand the effect of microbial treatment on physico-chemical parameters and phytotoxicity of leachate arising from degradation of municipal solid waste. Methods and statistical Analysis: Landfill leachate samples were collected from a municipal landfill site in Mumbai, India at different phases of its degradation cycle. The leachate was subjected to anaerobic treatment using microbial consortium based product CleanMaxx ANB followed by its counterpart CleanMaxx for aerobic treatment. Post treatment, the physico-chemical properties were analysed and the phytotoxicity was assessed using seed germination assay. The results were interpreted using ANOVA. Findings: The physicochemical parameters of the old and fresh leachate samples were analyzed after biological treatment where the percentage COD reduction was 18.97% and 53.87%; percentage ammoniacal nitrogen reduction was 22.78% and 58.8 %; percentage reduction in TDS was 24.8% and 34.76%; percentage reduction in TSS was 24.05% and 23.5% and percentage colour reduction was 25.01% and 34.35% for old and fresh leachate respectively. The aging of landfill leachate sample may have reduced its biodegradable fraction with the increase in the concentration of high molecular compounds and highly toxic compounds, which may hinder with the microbial degradation process. The seed germination bioassay using Cicer arietinum (Bengal gram) seeds revealed that the percentage germination of seeds exposed to untreated leachate samples (both old and fresh) was 11.1 and 22.2% respectively (p<0.05). Microbial treatment of both these samples improved the germination percentage to 88.8% in both cases. Application/Improvements: The improvement in physicochemical properties and reduction in phytotoxicity indicates that the microbial remediation of landfill leachate could treat the top soils and groundwater tables at contaminated sites, making the surrounding land arable.Keywords: Landfill, Leachate, Microbial Degradation, Phytotoxicity

N-myristoyltaurine capped copper nanoparticles for selective colorimetric detection of Hg2+ in wastewater and as effective chemocatalyst for organic dye degradation

The discharge of organic dyes and hazardous heavy metals from diverse industries into the environment has become a serious problem. Herein, we report that N-myristoyltaurine capped copper nanoparticles (CuNPs) speeds up the decolorization of dye effluents in the presence of sodium borohydride (NaBH4). The decolorization followed by UV–visible spectroscopy revealed that the reaction follows pseudo first-rate kinetics. All the tested dyes decolorized in less than 3 min. As a result of decolorization, the toxicity of the dye effluents decrease considerably, which was proved by seed germination assay. Further, the surface plasmon resonance property of the CuNPs was explored for selective and sensitive detection of hazardous mercury ions in sewage water (SW) and artificial cerbospinal fluid (aCSF). In the presence of Hg2+, galvanic displacement reactions promote the aggregation and the color change of CuNPs from wine red to grayish white. On the basis of colorimetric change, a minimum concentration of 15 μM of Hg2+ can be detected by the naked eye. The spectrophotometric detection method showed a detection limit of 0.1125 μM. Interference studies suggest that CuNPs is highly sensitive to Hg2+ ions. Recovery experiments proved that CuNPs quantitatively detect the spiked Hg2+ ions in tap water, SW and aCSF with an acceptable recovery range of 92 to 113%. Overall, the experimental outcomes suggest that the CuNPs could be deployed as a catalyst to decolorize dye effluents and as a colorimetric probe for mercury detection in wastewater.

The non-DNA binding bHLH transcription factor Paclobutrazol Resistances are involved in the regulation of ABA and salt responses in Arabidopsis

Abscisic acid (ABA) is the key hormone that regulating plant responses to abiotic stresses. Several basic helix-loop-helix (bHLH) transcription factors have been reported to regulate ABA signaling in Arabidopsis. Paclobutrazol Resistances (PREs) are non-DNA binding bHLH transcription factors involved in the regulation of plant response to several different plant hormones including gibberellin, brassinosteroid and auxin. Here, we show that PREs are involved in the regulation of ABA and salt responses in Arabidopsis. Quantitative RT-PCR results showed that the expression levels of PRE6 as well as several other PRE genes were reduced in response to ABA treatment, but increased to salt treatment. Seed germination assays indicated that ABA sensitivity is reduced in the pre6 mutants, but increased in transgenic plants overexpressing PRE6. On the other hand, the 35S:PRE6 transgenic plants showed enhanced tolerance to salt, whereas little, if any changes were observed in the pre6 mutants. Similar responses to ABA and salt treatments were observed in the pre2 mutants and the transgenic plants overexpressing PRE2, and a slight increased resistance to ABA in seed germination was observed in the pre2 pre6 double mutants. Taken together, our results suggest that at least some of the PRE genes are ABA responsive genes, and PREs may function redundantly to regulate ABA and salt responses in Arabidopsis.

Phytochrome Regulation of Seed Germination.

Seed germination assays consist of counting the number of germinated seeds, defined as seeds in which the radicle has ruptured the endosperm and emerged from the seed coat. In Arabidopsis seed germination assays, Arabidopsis seeds are surface-sterilized, plated on agar plates containing test compounds, and incubated at specific temperatures under specific light conditions, after which the germinated seeds are counted, either with the naked eye or under a microscope. This chapter describes step-by-step protocols for Arabidopsis seed germination assays under phytochrome-dependent conditions.

Physico-chemical, microbial and phytotoxicity evaluation of composts from sorghum, finger millet and soybean straws

PurposeComposting is an environmentally sustainable alternative for bioconversion of agricultural residues into a nutrient-rich product that can enhance soil fertility/microbial diversity and thereby improve agricultural productivity. The goal of the current study was to evaluate the decomposition pattern of the agro-residues and assess the maturity and phytotoxicity of the composts obtained using physico-chemical, microbial and statistical analyses. The study also attempted to determine a threshold germination index (GI) to serve as a maturity index for the composts by conducting seed germination assays with tomato, chickpea and soybean seeds.MethodsThree agricultural residues/straws of Eleusine coracana (finger millet), Sorghum bicolor (sorghum) and Glycine max (soybean) were subjected to aerobic composting for a period of 60 days to study the impact of saw dust on the decomposition pattern and the ultimate compost quality/characteristics.ResultsThe results showed efficient decomposition pattern of the agricultural residues characterized by high temperature profiles (up to 70 °C), high microbial activity, a sharp decrease in C/N ratio of the composting materials, i.e., from an initial 41–61 to final 10–17.ConclusionsStatistical evaluation of seed germination assays showed that only the compost obtained from sorghum straw + saw dust was mature and free from any phytotoxicity as all the tested seeds showed higher and statistically significant GIs. It was difficult to attribute a single threshold GI value to indicate maturity of compost and could not further be applied to different types of composts as different seeds responded differently to the same compost.

Anaerobic Co-digestion of Catering and Agro-Industrial Waste: A Step Forward Toward Waste Biorefinery

In the present study a biorefinery system is proposed using catering and agro industrial waste for biogas and low phytotoxic digestate. Anaerobic co-digestion of catering waste with partially pretreated (microwave 800 J/g/min + steam 121 °C 40 min) maize crop residues was conducted under different composition (20-50%) of feedstock. The results showed that the biogas production was increased by 2.03 times in co-digestion experiment (40 % partially pretreated maize crop residue + 60 % catering waste: TCM3) as compared to catering waste alone (control). The increment in accumulative methane 116.7 m3 t-1 was recorded in TCM3 which is due to improvement in biodegradation under co-digestion process. The post digestion byproduct (residual digestate) was evaluated for its phytotoxicity which is supplied with aerobic post treatment. Thethe post treatment has improved the digestate quality by decreasing VS/TS ratio from 259 g/L to 173 g/L and slightly increase the pH from 7.29 to 8.32. Seed germination assay showed that the germination percentage (G %), germination index (GI) and vigor index (VI) were relatively higher with post treated digesate as compared to un-treated digestate. In the germination test using wheat seeds, the post treated digestate (5 % sol. extract) achieved higher values of GI and VI (46 and 609) whereas in un-treated,values for these indices were 14 and 62 respectively. Overall the findings of the present study identify the significance of co-digestion based waste biorefinery, in order to develop value added bio-products such as biogas and biofertilizers.

Decomposition of poultry litter through vermicomposting using earthworm Drawida sulcata and its effect on plant growth

Poultry litter contains an enormous amount of nutrients that create environmental problems like eutrophication and phytotoxicity. These challenges can be mitigated by stabilizing its nutrients using earthworms. The objective of the present study was to decompose poultry litter amended with cow dung and Tectona grandis leaf litter into vermicompost (VC) using Drawida sulcata, relatively a new earthworm species. D. sulcata is a hardy species, and its survival rate was high during the vermicomposting process under alkaline pH condition. D. sulcata improved the quality of vermicompost by increasing the level of nutrients like total nitrogen, total phosphorous and total potassium and decreased pH, organic carbon and carbon/nitrogen ratio. The quality of VC was checked through seed germination assay using Trigonella foenum-graecum. In comparison with control, 20% (20 g VC + 100 ml water) concentration of VC extract showed a statistically significant (P < 0.05) increase in seed germination, while 100% (100 g VC + 100 ml water) a decreased seed germination displaying phytotoxicity. Plant growth studies using Abelmoschus esculentus were conducted by amending soil with different concentrations of VC such as V1 (100% soil + 25% VC), V2 (100% soil + 50% VC), V3 (100% soil + 75% VC), V4 (100% soil + 100% VC) and control (C) (1 kg garden soil). Maximum plant growth was noticed in V3 and V2 treatments. The present study confirms that D. sulcata, an epigeic earthworm, can be used for in situ degradation of poultry litter.

A comparative multi-assay approach to study the toxicity behaviour of Eu2O3 nanoparticles

Europium oxides (Eu2O3) nanoparticles are extensively employed in diverse areas ranging from bioimaging to chemical sensing. However, still there is significant lack of information regarding their toxic behaviour on humans and the environment. The endeavor of this work is to develop structural/toxicity correlations for bare and surface functionalized Eu2O3 nanoparticles synthesized by low-temperature colloidal route. The detailed investigations revealed that Eu2O3 nanoparticles concentration have significant effect on the in vitro toxicity. On the basis of antibacterial, antimicrobial assays and assessment of the genotoxicity using Allium cepa and molecular studies on human blood DNA, it was discovered that surface modification of nanoparticles is an important parameter for reducing the toxicity of Eu2O3 nanoparticles. The phytotoxicity of the prepared nanoparticles has also been compared by the seed germination assay with wheat, green grams, and black chickpeas. The detailed results revealed the mechanism of Eu2O3 nanoparticles in vitro toxicity.

Bare and nonionic surfactant-functionalized praseodymium oxide nanoparticles: Toxicological studies

The applications of praseodymium oxide (Pr6O11) nanomaterials in catalysis, oxygen storage materials, and optical devices are the emergent areas that possess an urgent requirement for the toxicological evaluation of these nanomaterials to determine their impact on the ecology. In the present work, we have employed a multiassay approach for the toxicological profiling of bare and nonionic surface-modulated Pr6O11 nanoparticles (NPs). The contemporary analysis in this work has presented a great prospect to develop efficient indicators and inspect the toxic nature of bare and functionalized Pr6O11 NPs. The effect of Pr6O11 NPs was analyzed on germination parameters by the wheat seed germination assay and on algal growth by the paper disc approach. The influence of Pr6O11 NPs on the percentage viability of four different types of bacteria, namely, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhi, was investigated. The substantial effect of different concentrations of Pr6O11 NPs on Allium cepa was investigated at the genomic level by using the chromosomal aberration assay. The functionalized NPs exhibited 41.05%-400% higher biocompatibility by the wheat seed germination assay and 27.1%-47.3% by the A. cepa chromosomal aberration assay than the bare NPs. In algal growth assay and antibacterial activity testing, biocompatibility of the developed functionalized NPs enhanced by 23.1%-37.1% and 10%-70.6%, respectively. The current work evaluated the toxicity of the NPs and measured the competence of the obtained data to characterize possibilities of probable threats, prominence of data requirement, and breaches that must be filled to diminish the ambiguities about the safe use of Pr6O11 NPs.

Diversity of culturable methylotrophic bacteria in different genotypes of groundnut and their potential for plant growth promotion.

This study aimed at documenting the culturable methylotrophic bacterial diversity across different groundnut genotypes and evaluating their effect on the growth of groundnut. 80 methylotrophic bacterial isolates were obtained from the phyllosphere of 15 groundnut genotypes collected from Tamil Nadu, India. The bacterial isolates were identified through sequencing of the 16S rDNA and were tested for their plant growth-promoting properties. Groundnut seeds were inoculated with methylotrophic bacteria and their effect on growth was evaluated via in vitro and pot experiments. Molecular identification revealed that the isolates belonged to 30 different species. A higher diversity of methylotrophic bacteria at genus and species level was found in groundnut genotype TMV2. Shannon diversity index was the highest in genotype TMV7, followed by VRI2 and TMV2. Similarly, geographical location also influenced the diversity of methylotrophic bacteria. In vitro seed germination assay revealed that methylotrophic isolates enhanced root growth and improved formation of root hair. The radicle length of treated seeds ranged from 2.7 to 8.4cm. A higher shoot length was observed in the plants from seeds treated with Methylobacterium radiotolerans VRI8-A4 (27.3cm), followed by Pseudomonas psychrotolerans TMV13-A1 (26.3cm) and Bacillus aryabhattai K-CO3-3 (23cm). The findings of this study strongly suggest that beneficial methylotrophic bacteria associated with the phyllosphere of groundnut play a major role in regulating plant growth.

Aspergillus terreus JF27 Promotes the Growth of Tomato Plants and Induces Resistance against Pseudomonas syringae pv. tomato

Certain beneficial microorganisms isolated from rhizosphere soil promote plant growth and induce resistance to a wide variety of plant pathogens. We obtained 49 fungal isolates from the rhizosphere soil of paprika plants, and selected 18 of these isolates that did not inhibit tomato seed germination for further investigation. Based on a seed germination assay, we selected four isolates for further plant tests. Treatment of seeds with isolate JF27 promoted plant growth in pot tests, and suppressed bacterial speck disease caused by Pseudomonas syringae pathovar (pv.) tomato DC3000. Furthermore, expression of the pathogenesis-related 1 (PR1) gene was higher in the leaves of tomato plants grown from seeds treated with JF27; expression remained at a consistently higher level than in the control plants for 12 h after pathogen infection. The phylogenetic analysis of a partial internal transcribed spacer sequence and the β-tubulin gene identified isolate JF27 as Aspergillus terreus. Taken together, these results suggest that A. terreus JF27 has potential as a growth promoter and could be used to control bacterial speck disease by inducing resistance in tomato plants.