Eggplant Roots Research Articles

Changes of eggplant roots and nutrient distribution in the ridge with frequent irrigation with small water quantity

Changes of eggplant roots and nutrient distribution in the ridge with frequent irrigation with small water quantity

The effect of lead pollution on nutrient solution pH and concomitant changes in plant physiology of two contrasting Solanum melongena L. cultivars.

Lead (Pb) is highly toxic to plants because it severely affects physiological processes by altering nutrient solution pH. The current study elucidated Pb-induced changes in nutrient solution pH and its effect on physiology of two Solanum melongena L. cultivars (cv. Chuttu and cv. VRIB-13). Plants were grown in black plastic containers having 0, 15, 20, and 25 mg L-1 PbCl2 in nutrient solutions with starting pH of 6.0. pH changes by roots of S. melongena were continuously monitored for 8 days, and harvested plants were analyzed for physiological and biochemical attributes. Time scale studies revealed that cv. Chuttu and cv. VRIB-13 responded to Pb stress by causing acidification and alkalinization of growth medium during the first 48 h, respectively. Both cultivars increased nutrient solution pH, and maximum pH rise of 1.21 units was culminated by cv. VRIB-13 at 15 mg L-1 Pb and 0.8 units by cv. Chuttu at 25 mg L-1 Pb treatment during the 8-day period. Plant biomass, photosynthetic pigments, ascorbic acid, total amino acid, and total protein contents were significantly reduced by Pb stress predominantly in cv. Chuttu than cv. VRIB-13. Interestingly, chlorophyll contents of cv. VRIB-13 increased with increasing Pb levels. Pb contents of roots and shoots of both cultivars increased with applied Pb levels while nutrient (Ca, Mg, K, and Fe) contents decreased predominately in cv. Chuttu. Negative correlations were identified among Pb contents of eggplant roots and shoots and plant biomasses, leaf area, and free anthocyanin. Taken together, growth medium alkalinization, lower root to shoot Pb translocation, and optimum balance of nutrients (Mg and Fe) conferred growth enhancement, ultimately making cv. VRIB-13 auspicious for tolerating Pb toxicity as compared with cv. Chuttu. The research outcomes are important for devising metallicolous plant-associated strategies based on plant pH modulation response and associated metal uptake to remediate Pb-polluted soil.

Review of Historical, Health Benefts and Uses of Eggplants by Humankind

Eggplants are non-climacteric fruits which were seen growing wild in the forest of India and is currently described as one of the ten world's healthiest food. The objective focused on the review of general description, health and usefulness of eggplant. Eggplants grow into 98 different species with different shapes and colours. They reduce the risk of cancer, cardio vascular diseases, pre-menstrual syndrome, amenorrhea, ante natal anaemia and cholesterol. They also soak injurious chemicals, enables weight loss and manages diabetes. Finally, the leaves, stem, fruit and roots of eggplant are used for food, fuel, curer of diseases, rituals and for decoration

Early burst of reactive oxygen species positively regulates resistance of eggplant against bacterial wilt

AbstractReactive oxygen species (ROS) play a crucial role in the early response to plant biotic and abiotic stresses. In this study, bacterial wilt‐resistant and wilt‐susceptible eggplants were inoculated with Ralstonia solanacearum and the ROS content was analysed. The result revealed an increased accumulation of hydrogen peroxide (H2O2) and superoxide (O2−) in resistant and susceptible eggplant roots after R. solanacearum inoculation. H2O2 and O2− accumulation increased earlier in the inoculated resistant eggplant root than in the inoculated susceptible eggplant root. Real‐time polymerase chain reaction results revealed that respiratory burst oxidase homologue (Rboh) A, RbohB, RbohF and PR1 expression levels increased in inoculated resistant eggplant roots at an early stage (0–60 h postinoculation) and were at higher expression levels than those in susceptible eggplant roots. Ascorbate peroxidase, peroxidase and catalase activities were higher in inoculated resistant eggplant roots than in susceptible eggplant roots at the early stage. Hence, an early ROS burst positively regulates bacterial wilt resistance in eggplant.

A spiking strategy facilitates housekeeping selection for RT-qPCR analysis under different biotic stresses in eggplant.

Endogenous housekeeping genes are traditionally employed to normalize the expression of target genes in RT-qPCR studies. Assuming that a perfect housekeeping suitable for every condition does not exist, expression stability of the chosen reference gene should be evaluated at every new experiment. The housekeeping selection process reveals furthermore complicated and time-consuming when different conditions have to be compared in the same experimental dataset. As an alternative strategy, we spiked an external reference transcript (ERT) into all RNA samples of our dataset (eggplant roots subjected to different biotic stresses), and used it to normalize the expression levels of native candidate housekeeping. ERT expression resulted highly stable across all samples and enabled to indicate glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as the most stable endogenous housekeeping. This result was confirmed by the use of GeNorm, Normfinder, and BestKeeper algorithms. This method might be generally applied to expedite the selection process of the best reference gene.

Eggplant roots and nutrient distribution in the ridge in two greenhouses with solar-mediated or timer controlled-fertigation

Eggplant roots and nutrient distribution in the ridge in two greenhouses with solar-mediated or timer controlled-fertigation

Inducing cell wall-bound phenolic compounds by elicitors in eggplant (Solanum melongena)

We investigated the effect of elicitation on cell wall strengthening in eggplant roots caused by 6 elicitors viz., chitosan (CH), salicylic acid (SA), methyl jasmonate, methyl salicylate and vitamins B2 and B12. Analysis of phenolic metabolites from eggplant roots by HPLC revealed presence of 6 major cell wall-bound phenolic compounds. They were 4-hydroxybenzoic acid (4-HBA), vanillic acid (VA), 4-hydroxybenzaldehyde (4-HBAld), vanillin (VAN), 4-coumaric acid (4-CA) and ferulic acid (FA). In eggplant roots, the concentrations of FA, VA and 4-HBA were 188.71, 113.64 and 109.42 μg/g DW, respectively, and they were higher than those of 4-HBAld, VAN and 4-CA. When elicited roots were analyzed by HPLC, quantitative differences could be clearly discerned in the amount of the phenolic compounds. After 48 h post-elicitation (hpe) in the presence of CH, the increase in 4-HBA, 4-CA and FA contents in cell wall was 2.6-, 2.8- and 3.0-fold, respectively, compared with control. After 72 hpe, in the presence of SA, the increase in 4-HBA, 4-CA and FA levels was 3.5-, 2.9- and 3.8-fold, respectively, compared with the control. As the elicitors have specific receptors in plants, it may be possible to utilize CH and SA for inducing resistance against important diseases in eggplant.

English

The effect of two rhizobacteria, Pantoea agglomerans and Bacillus subtilis on parasitism of the root-knot nematodes, Meloidogyne javanica on eggplants was evaluated in laboratory and greenhouse experiments. The impacts of the bacteria application as seed treatment, root dipping, and soil drench on early nematode penetration into plant roots, as well as, on eggplant growth were tested. The number of penetrated second stage juveniles of M. javanica was significantly reduced after P. agglomerans and B. subtilis application at concentration of 108 CFU ml-1. P. agglomerans increased the eggplant fresh shoot and root weight following seed treatment. In the greenhouse experiment the bacteria were applied alone and in combination with a carbamate nematicide, Oxamyl (Vydate®). P. agglomerans was able to suppress M. javanica development into plant roots through a first half of eggplant cropping season. At the end of cropping season B. subtilis significantly reduced root gall index and number of nematode juveniles in soil and roots. This bacterium applied in combination with Oxamyl was the most efficient against M. javanica reproduction. Thereby, B. subtilis might be considered as a good candidate for biological or integrated control of the root knot nematodes. Key words: Bacillus subtilis, Pantoea agglomerans, biological control, plant growth, gall index, root knot nematode.

Characterization and quantitative analysis of phenylpropanoid amides in eggplant (Solanum melongena L.) by high performance liquid chromatography coupled with diode array detection and hybrid ion trap time-of-flight mass spectrometry.

Eggplant (Solanum melongena L.) is a famous edible and medicinal plant. Despite being widely cultivated and used, data on certain parts other than the fruit are limited. The present study focused on the qualitative and quantitative analysis of the chemical constituents, particularly phenylpropanoid amides (PAs), in eggplant. The mass fragmentation patterns of PAs were proposed using seven authentic compounds with the assistance of a hybrid ion trap time-of-flight mass spectrometer. Thirty-seven compounds (27 PAs and 10 others) were detected and plausibly assigned in the different parts of eggplant. Afterward, a reliable method based on liquid chromatography coupled with diode array detection was developed, validated, and applied for the simultaneous determination of seven PAs and three caffeoylquinic acids in 17 batches of eggplant roots with satisfactory accuracy, precision, and reproducibility, which could not only provide global chemical insight of eggplant but also offer a reliable tool for quality control.

Effect of duration of irrigation on the infectivity and reproduction of the root-knot and the reniform nematodes on some vegetable crops grown in two different soil types

Influence of changes of soil moisture due to the durations of irrigation on thedevelopment and reproduction of the root-knot (M. incognita) and the reniform (R.reniformis) nematodes infecting eggplant, squash and cowpea in two different soiltypes was studied under greenhouse conditions. Results showed that the highestcounts of the root-knot nematode were recorded on roots of eggplant grown inloamy sand soil and irrigated at the fourth day. On squash, the highest nematodecounts were recorded on plants grown in sandy loam soil and irrigated every day,and on cowpea roots grown in the same soil type but irrigated every four days.Higher reproductivity values of the reniform nematode on eggplant roots wereaccomplished in loamy sand soil and irrigated every four days. Significant higherfinal population and rate of reproduction on squash and cowpea were recorded onplants grown in the same soil type but irrigated daily or every other day,respectively. The influence of the duration of irrigation on nematode developmentdepend on many factors most of which are the soil type, duration of irrigation,nematode species as well as the growing crop. The prolonging irrigation period(decreasing soil moisture) significantly reduced the growth of the infected plants.Such effect was pronounced with the longest period between irrigation (3 days) inloamy sand soil.

Evaluation of some growth promoting bacterial strains exist on Eggplant root Solanumm elongena L. against Rhizoctonia solani

In this study, six plant growth promoting bacterial strains were tested against eggplant root rot disease caused by Rhizoctonia solani. The bacterial strains were evaluated for their ability to promote growth and control R. solani in eggplant under greenhouse conditions. The results of antagonistic activity of the bacterial strains against R. solani showed that the tested strains controlled the radial growth of R. solani ranging from 24.66 to 40.33 mm, of these, Bacillus subtilis was the most promising strains which recorded 24.66 mm. Results of the treatment eggplant seeds with the bacterial suspension of the six strains showed that all tested strains significantly increased the percentage of seeds germination as compared to control treatment, B. subtilis strain was the best which recorded 92.16% as compared to 69.56% for control treatment. The greenhouse experiment revealed that the plants treated with B. subtilis recorded maximum (Shoot length, root length, fresh and dry weight of plant, rate of fruits weight, plant productivity). All these parameters were increased by 93.83 cm, 26.50 cm, 589.30 g/ plant, 163.03 g/ plant, 101.63 g, 1180 g/ plant respectively, also the results showed B. subtilis significantly decreased disease incidence and severity of eggplant infected by R. solani which recorded 34.06, 0.23 respectively as compared to both positive without pathogen and negative with pathogen control treatment (4.4 %, 77.33), (0.07 %, 0.71) respectively.

Desenvolvimento radicular da berinjela irrigado e de sequeiro em diferentes formas de cultivo

Aiming to evaluate the density and distribution of roots of eggplant with supply of organic fertilizer and chemical application will be submitted and no drip irrigation method in ultisol, there was an experiment in Aquidauana-MS. The design was randomized blocks with split plots, using four blocks. Treatments used in the plots corresponded to eggplant and without irrigation and the subplots consisted of organic fertilizer and chemical industries. Irrigation was performed based on the evaporation of the Class A pan and through tensiometer. The organic and chemical fertilization using urea and organoeste respectively, were performed at 45, 60 and 75 days after transplanting (DAT). The gathering of roots were done at 113 DAT for this using an auger hole, and taking samples at three distances from the plant stem (zero, 0.2 and 0.4 m) and four soil depths (0.00-0.10, 0.10-0.20 0.20-0.30 and 0.30-0.40 m) were then washed, taken to oven and weighed on an analytical balance. It follows that the effective depth of the root system of drip irrigated eggplant by both fertilization is a maximum of 0.20 m.

Potential of Pseudomonas and Bacillus Isolates as Biocontrol Agents Against Fusarium Wilt of Eggplant

ABSTRACTPlant growth-promoting rhizobacteria (PGPR) are beneficial bacteria found on plant roots that induce growth by a wide variety of mechanisms. Ten isolates of Pseudomonas and Bacillus were isolated from eggplant rhizosphere soil and evaluated for their volatile compound efficacy against mycelial growth of Fusarium oxysporum f. sp. melongenae (Fomg) and tested for their ability to colonize eggplant (Solanum melongena L.) roots in vitro. PGPR strains inhibited mycelial growth of the target pathogen and the percentage of inhibition varied from 38% to 72% by means of inhibitory activities. Pseudomanas aeruginosa (P07–1) and P. putida (P11–4) were determined to be successful colonizers in eggplant seedlings. Also, a pot experiment was conducted to assess the induced resistance to Fusarium wilt of eggplant by PGPR strains. Among the PGPR isolates, P. aeruginosa (P07–1), P. putida (P11–4), P. aeruginosa (85A-2), Bacillus amyloliquefaciens (76A-1) and B. cereus (B10a) significantly reduced Fusarium wilt disease incidence by up to 85%. However, their combination was not more effective in suppressing the disease than the application of those isolates alone. The induction of peroxidase (POX, EC 1.11.1.7) and polyphenol oxidase (PPO, EC 1.14.18.1) enzymes was found to be significantly higher in comparison with the control group. Similarly, the proline levels in eggplants showed an increasing trend with the above isolates. However, catalase (CAT, 1.11.1.6) activity was not found to significantly contribute to the induced resistance mechanism. This study revealed that the promising PGPR isolates could be potentially very useful for the biocontrol of Fomg via enhancing disease resistance in eggplant plants.

Nonomuraea solani sp. nov., an actinomycete isolated from eggplant root (Solanum melongena L.)

A novel actinomycete, designated strain NEAU-Z6(T), was isolated from eggplant (Solanum melongena L.) root. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain NEAU-Z6(T) belonged to the genus Nonomuraea, with highest sequence similarity to Nonomuraea monospora PT 708(T) (98.83 %), Nonomuraea rosea GW 12687(T) (98.55 %) and Nonomuraea rhizophila YIM 67092(T) (98.02 %). Sequence similarities between strain NEAU-Z6(T) and other species of the genus Nonomuraea ranged from 97.94 % (Nonomuraea candida HMC10(T)) to 96.30 % (Nonomuraea wenchangensis 210417(T)). Key morphological, physiological and chemotaxonomic characteristics of strain NEAU-Z6(T) were congruent with the description of the genus Nonomuraea. The G+C content of the genomic DNA was 64.51 mol%. DNA-DNA relatedness and comparative analysis of physiological, biochemical and chemotaxonomic data allowed genotypic and phenotypic differentiation of strain NEAU-Z6(T) from closely related species. Thus, strain NEAU-Z6(T) represents a novel species of the genus Nonomuraea, for which the name Nonomuraea solani sp. nov. is proposed. The type strain is NEAU-Z6(T) ( = CGMCC 4.7037(T) = DSM 45729(T)).

Antifungal activity of different extracts of Ageratum conyzoides for the management of Fusarium solani

Ageratum conyzoides L. is potential allelopathic weed very useful for its antifungal and antimicrobial activity. Being environmentally safe and friendly, it has the potential to substitute synthetic fungicides. The current study, therefore, was designed to evaluate the in vitro efficacy of aqueous methanolic and n-hexane extracts of A. conyzoides against the pathogenic fungi, Fusarium solani Mart. (Sacc.), isolated from roots of egg plant ( Solanum melongena ). The target fungus was exposed to various concentrations (2, 4 and 6% w/v) of aqueous, methanolic and n-hexane extracts of Inflorescence, leaf, stem and root. All the employed concentrations of extracts of four plant parts significantly suppressed the growth of the target fungal pathogen. The n-hexane extracts of leaf and inflorescence caused highly significant reduction of 84% in growth of F. solani followed by stem and root extracts which caused which caused 80% and 72% reduction in growth, respectively. The same pattern in growth reduction was observed in methanolic and aqueous extracts. Among the four parts of the tested weed, different concentrations of the methanolic extract of leaf were found to be highly effective in controlling target fungal species resulting in up to 78% reduction in fungal biomass over control followed by inflorescence (74% reduction), stem (63% reduction) and root (59% reduction) at highest used concentration. In case of aqueous extracts, the maximum reduction was observed in leaf extract (72%) followed by inflorescence, stem and root, respectively. Key words: Ageratum conyzoides , aqueous extract, Fusarium solani , n-hexane extract, methanolic extract.

The effects of biological control on fungal communities colonizing eggplant (Solanum melongena L.) organs and the substrate used for eggplant cultivation

Eggplants, cv. Black Beauty, were grown in the greenhouse of the University of Warmia and Mazury in Olsztyn. During the growing season, the plants were sprayed three times with Asahi SL, Biochikol 020 PC and Bravo 500 SC, they were watered with Polyversum, and a mycorrhizal inoculum was applied to the roots of seedlings. Unprotected plants, treated with distilled water, served as control. After fruit harvest, samples of the substrate used for eggplant cultivation, eggplant stems and roots were collected, and fungi were isolated in the laboratory. The fungal soil community was more abundant and diverse than the communities colonizing the stems and roots of eggplants. The applied biological and chemical control agents effectively reduced the abundance of fungi, including pathogenic species, in the organs of eggplants and the substrate used for eggplant cultivation. Potential pathogens (<i>Alternaria alternata</i>, <i>Botrytis cinerea</i> and <i>Fusarium</i> species) were isolated in high numbers from eggplant stems in the control treatment and in the Polyversum treatment (67%). The lowest number of potential pathogenic species were isolated from plants treated with the biostimulator Asahi SL, the fungicide Bravo 500 SC and the mycorrhizal inoculum. The population size of pathogenic fungi (<i>Colletotrichum coccodes</i> and <i>Fusarium</i>) isolated from eggplant roots was smaller, compared with stems, particularly in the treatments with the fungicide Bravo 500 SC and the biostimulator Biochikol 020 PC. The soil fungal community was dominated by yeast-like fungi (over 60% of all isolates). Fungi known as potential causal agents of diseases were found in low abundance, and they were not detected in substrate samples collected from under fungicide-treated eggplant plants.

English

The contents of cinnamic acid and vanillin in eggplant root exudates and soil were determined by HPLC. The results showed that cinnamic acid and vanillin might remain in soil after the root of eggplant is released. With the extending growth stage and planting year of eggplant, the contents in root exudates, rhizosphere and continuous cropping soil increased. In bioassay and field studies, the allelopathy of cinnamic acid and vanillin to the verticillium wilt (V. dahliae) and the eggplant was observed, and when the concentration of cinnamic acid or vanillin was at 1 and 4mmol ⇦ -1, it inhibited the eggplant growth, while the occurrence of verticillium wilt was promoted. A high concentration of cinnamic acid and vanillin caused eggplant autotoxicity and increased the risk of disease infection, which finally led to continuous cropping obstacle. Keywords: Cinnamic acid, vanillin, root exudates, soil, verticillium wilt, continuous cropping obstacle

English

Elicitors are capable of mimicking the perception of a pathogen by a plant, thereby triggering induction of a sophisticated defense response in plants. In this study, we investigated an induced resistance in eggplant in respect to cell wall strengthening and defense enzyme activation affected by four elicitors such as, chitosan (CHT), salicylic acid (SA), methyl salicylate (MeSA) and methyl jasmonate (MeJA). The increase in total phenolic content of eggplant roots by the elicitors was significantly higher. Lignin deposition in the cell wall of eggplant roots was increased 5, 4, 3 and 3 times by SA, CHT, MeJA and MeSA at 96 h of elicitation, respectively. Phenylalanine ammonia-lyase (PAL) activity showed an increase of 4.7, 3.7, 3.5 and 3.2 times by SA, CHT, MeJA and MeSA at 36 h of elicitation, respectively. Highest activity of peroxidase (POD) was observed at 24 h after elicitation under the precise influence of CHT and SA. The activities of polyphenol oxidase (PPO), cinnamyl alcohol dehydrogenase (CAD) and catalase (CAT) were also increased several folds by the elicitors. Accumulation of phenolics and lignin in high amounts, together with higher level activity of major defense enzymes in response to the elicitors, may bolster eggplants in mounting practical and effective resistance against Ralstonia solanacearum, the devastating wilt pathogen. Key words: Catalase, chitosan, cinnamyl alcohol dehydrogenase, lignin, methyl jasmonate, methyl salicylate, phenylalanine ammonia lyase, peroxidase, salicylic acid, Solanum melongena.

Nematicidal activity of leaf extracts from Lantana camara L. against Meloidogyne incognita (kofoid and white) chitwood and its use to manage roots infection of Solanum melongena L.

Various concentrations of aqueous leaf extract of Lantana camara were assessed in vitro conditions against second stage juveniles (J2) of Meloidogyne incognita. The standard concentration 'S' of leaf extract was found to be highly nematostatic, where nematodes were completely paralyzed after 12 h and after 48 h of exposure, 96% of juveniles were killed at same concentration. However, the mortality of juveniles was 75% in S/2 dilution at 48 h. The degree of effectiveness and dilutions of extract were directly proportional. The percentage of paralyzed juveniles was decreased, when J2 transferred in distilled water after 48 h incubation in standard aqueous leaf extract. Addition of freeze-dried aqueous extract to sterile sandy substrate at S/2 dilution significantly decreased the root-knot infection to susceptible eggplants whereas second stage juveniles (J2) that penetrated roots of eggplant were able to complete development in sterile sandy substrate without treatment of freeze-dried aqueous extract.

Roles of the catalytic subunit of cAMP-dependent protein kinase A in virulence and development of the soilborne plant pathogen Verticillium dahliae

Verticillium dahliae is a soilborne fungus that causes vascular wilt disease in a broad range of hosts and survives for many years in the soil in the form of microsclerotia. Although the role of cAMP-dependent protein kinase A (PKA) has been extensively studied in foliar pathogens, there is limited information about its role in soilborne fungal pathogens that infect through the root system. Genome database search revealed the presence of two PKA catalytic subunit genes in V. dahliae, named VdPKAC1 and VdPKAC2. A phylogenetic analysis showed that VdPKAC2 groups with fungal PKA catalytic subunits that appear to play a minor role in PKA activity. This gene was expressed considerably lower than that of VdPKAC1. Although disruption of VdPKAC1 did not affect the ability of V. dahliae to infect through the roots of tomato and eggplant, disease severity was significantly reduced. Since pathogen-derived ethylene is presumed to play a major role in symptom induction in vascular wilt diseases, ethylene generation was measured in fungal culture. The mutants defective in VdPKAC1 produced less ethylene than the corresponding wild type strains, suggesting a regulatory role of PKA in ethylene biosynthesis. Growth rates of these mutants were similar to those of wild type strains, while the rate of spore germination was slightly elevated and conidia production was significantly reduced. When grown on minimal media, the mutants showed greater microsclerotia production compared with the wild type strains. These results suggest multiple roles of VdPKAC1, including virulence, conidiation, microsclerotia formation, and ethylene biosynthesis, in the soilborne fungus V. dahliae.