Histopathological Changes and Enzymatic Activities Induced by Meloidogyne incognita on Resistant and Susceptible Potato

All potato cultivars are susceptible to root-knot nematodes (Meloidogyne spp.) which infest the roots and induce galls on the surface and necrotic spots in the flesh tuber of potato, Solanum tuberosum. Infested tubers are unacceptable for processing and fresh market. Tubers are also putative source of dissemination of the nematode. A French nematode- resistant tetraploid potato genotype gained from ex-S. sparsipilum material hybridized with S. tuberosum in F1 and in their back cross progenies and designated as 02T.155.6 was tested and compared in the present study in Egypt as a suitable different environment. Histopathological changes and chitinase activity induced by M. incognita population, of common occurrence in Egypt, in four French tetraploid materials and two common cultivars known as nematode- resistant and susceptible potato genotypes were investigated. Hypertrophied cells were initiated in both cortical and steler regions of the roots which were then developed to abnormal xylem elements expanding into the cortex in French susceptible genotypes designated as 02T.149.6, 02T.150.54, and 02T.157.16. Nematode within the vascular tissue (stele) could induce giant cell development close to nematode heads. The largest number of such induced cells was shown by the cultivars Spunta and Diamant. The clone 02T.155.6 with putative nematode resistance demonstrated none or very little nematode development. Recently dead second stage juveniles could also indicate incompatible plant reaction to the invading nematodes in 02T.155.6. M. incognita, Giza population, resistance was generally more coherent to 02T.155.6 as demonstrated by our histological investigations but less coherent as shown by another Egyptian M. incognita population. Chitinase activity was enhanced in M. incognita (Giza)-inoculated with respect to uninoculated roots in all plants. After inoculation, such an activity generally increased more in roots of a potato genotype previously known to have resistance or relatively low numbers of both nematode galls and eggmasses than in the other tested cultivars. Peroxidase and catalase activities of nematode- inoculated with respect to uninoculated potato roots were presented and discussed.

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Phytol, a constituent of chlorophyll, induces root-knot nematode resistance in Arabidopsis via the ethylene signaling pathway

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-07-20-0186-r ◽

2020 ◽

Author(s):

Taketo Fujimoto ◽

Hiroshi Abe ◽

Takayuki Mizukubo ◽

Shigemi Seo

Keyword(s):

Nematode Resistance ◽

Ethylene Signaling ◽

Severe Damage ◽

Root Knot Nematode ◽

Chlorophyll Contents ◽

Aerial Parts ◽

Wide Range ◽

Ethylene Signaling Pathway ◽

Meloidogyne Spp ◽

Arabidopsis Mutant

Root-knot nematodes (RKNs; Meloidogyne spp.) parasitize the roots and/or stems of a wide range of plant species, resulting in severe damage to the parasitized plant. The phytohormone ethylene (ET) plays an important role in signal transduction pathways leading to resistance against RKNs. However, little is currently known about the induction mechanisms of ET-dependent RKN resistance. Inoculation of Arabidopsis (Arabidopsis thaliana) roots with RKNs decreased chlorophyll contents in aerial parts of the plant. We observed accumulation of phytol, a constituent of chlorophyll and a precursor of tocopherols, in RKN-parasitized roots. Application of sclareol, a diterpene that has been shown to induce ET-dependent RKN resistance, to the roots of Arabidopsis plants increased phytol contents in roots accompanied by a decrease in chlorophyll in aerial parts. Exogenously applied phytol inhibited RKN penetration of roots without exhibiting nematicidal activity. This phytol-induced inhibition of RKN penetration was attenuated in the ET-insensitive Arabidopsis mutant ein2-1. Exogenously applied phytol enhanced the production of α-tocopherol and expression of VTE5, a gene involved in tocopherol production, in Arabidopsis roots. α-Tocopherol exerted similar induction of RKN resistance as phytol and showed increased accumulation in roots inoculated with RKNs. Furthermore, the Arabidopsis vte5 mutant displayed no inhibition of RKN penetration in response to phytol. These results suggest that exogenously applied phytol induces EIN2-dependent RKN resistance, possibly via tocopherol production.

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Heterologous Expression of the Mi-1.2 Gene from Tomato Confers Resistance Against Nematodes but Not Aphids in Eggplant

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-19-0383 ◽

2006 ◽

Vol 19 (4) ◽

pp. 383-388 ◽

Cited By ~ 64

Author(s):

Fiona L. Goggin ◽

Lingling Jia ◽

Gowri Shah ◽

Stephanie Hebert ◽

Valerie M. Williamson ◽

...

Keyword(s):

Genetic Background ◽

Meloidogyne Javanica ◽

Nematode Resistance ◽

Macrosiphum Euphorbiae ◽

Leucine Rich Repeat ◽

Root Knot Nematode ◽

Potato Aphid ◽

Tomato Line ◽

Meloidogyne Spp ◽

Susceptible Tomato

The Mi-1.2 gene in tomato (Solanum lycopersicum) is a member of the nucleotide-binding leucine-rich repeat (NB-LRR) class of plant resistance genes, and confers resistance against root-knot nematodes (Meloidogyne spp.), the potato aphid (Macrosiphum euphorbiae), and the sweet potato whitefly (Bemisia tabaci). Mi-1.2 mediates a rapid local defensive response at the site of infection, although the signaling and defensive pathways required for resistance are largely unknown. In this study, eggplant (S. melongena) was transformed with Mi-1.2 to determine whether this gene can function in a genetic background other than tomato. Eggplants that carried Mi-1.2 displayed resistance to the root-knot nematode Meloidogyne javanica but were fully susceptible to the potato aphid, whereas a susceptible tomato line transformed with the same transgene was resistant to nematodes and aphids. This study shows that Mi-1.2 can confer nematode resistance in another Solanaceous species. It also indicates that the requirements for Mi-mediated aphid and nematode resistance differ. Potentially, aphid resistance requires additional genes that are not conserved between tomato and eggplant.

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First Report of the Root-Knot Nematode Meloidogyne floridensis on Tomato (Lycopersicon esculentum) in Florida

Plant Disease ◽

10.1094/pd-89-0527b ◽

2005 ◽

Vol 89 (5) ◽

pp. 527-527

Author(s):

G. T. Church

Keyword(s):

Lycopersicon Esculentum ◽

Field Experiments ◽

The United States ◽

The State ◽

Bromophenol Blue ◽

Root Knot Nematode ◽

Fresh Market ◽

Root Knot Nematodes ◽

First Report ◽

Meloidogyne Spp

The state of Florida is the largest producer of fresh market tomato (Lycopersicon esculentum L.) in the United States with 2003 yields of 634 million kg on 17,700 ha valued at 516 million dollars. Effective crop management is essential for production of vegetables in Florida because of the presence of intense pest pressure. The identification of the pests present is the first step in the development of a successful IPM (integrated pest management) program. Root-knot nematodes (Meloidogyne spp.) are common nematodes that parasitize vegetables in Florida and cause significant yield reductions when not properly managed. In 2003 field experiments, soil was collected from two research farms in Saint Lucie and Seminole counties in Florida. Galling caused by root-knot nematode was observed on tomato at both locations. Since females suitable for identification are difficult to obtain from field-grown roots, field soil was placed in pots in the greenhouse and planted with Lycopersicon esculentum cv. Rutgers. Standard morphological techniques, differential host tests, and isozyme phenotypes were used in nematode identification. Female root-knot nematodes were extracted from tomato roots and placed in extraction buffer (10% wt/vol sucrose, 2% vol/vol Triton X-100, 0.01% wt/vol bromophenol blue). The females were crushed, loaded on a polyacrylamide gel, and separated by electrophoresis using the PhastSystem (Amersham Biosciences, Piscataway, NJ). The activities of malate dehydrogenase and esterase enzymes were detected using standard techniques. Isozyme phenotypes consistent with Meloidogyne incognita (Kofoid and White) Chitwood and M. javanica (Treub) Chitwood as well as with the newly described M. floridensis Handoo (1) were observed at both locations. To our knowledge, this is the first report of M. floridensis naturally occurring on tomato in Florida. The identification and distribution of M. floridensis in vegetable production fields is important for disease management throughout the state since the host range is likely different from other Meloidogyne spp. Reference: (1) Z. A. Handoo et al. J. Nematol. 36:20, 2004.

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Effect of Dinitroanaline Herbicides in a Soil Medium on Snap Bean and Soybean

Weed Science ◽

10.1017/s0043174500066194 ◽

1976 ◽

Vol 24 (4) ◽

pp. 366-369 ◽

Cited By ~ 9

Author(s):

B. Esther Struckmeyer ◽

L. K. Binning ◽

R. G. Harvey

Keyword(s):

Glycine Max ◽

Phaseolus Vulgaris ◽

Vascular Tissue ◽

Cell Structure ◽

Cortical Region ◽

Soil Medium ◽

Snap Bean ◽

Anatomical Studies ◽

Xylem Elements ◽

Cellular Abnormalities

Anatomical studies determined the effect of 0.8, 1.7, and 3.4 kg/ha of penoxalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine]; AC-92390 (N-sec-butyl-3-4-dimethyl-2,6-dinitrobenzenamine); oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide); and trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) on the cell structure of snap bean (Phaseolus vulgarisL. ‘Tenderette’) and soybean[Glycine max(L.) Merr. ‘Corsoy’]. Cellular abnormalities in the swollen and brittle area of the stem of treated plants included thinnerwalled cells, elongated xylem elements, hypertrophy and hyperplasia of cells, and anomalous rings of vascular tissue in the cortical region. Injury caused by the four herbicides was similar in snap bean and soybean.

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Verticillium Wilt Incited by Verticillium dahliae in Eggplant Grafted on Solanum torvum in Italy

Plant Disease ◽

10.1094/pd-89-0777b ◽

2005 ◽

Vol 89 (7) ◽

pp. 777-777 ◽

Cited By ~ 5

Author(s):

A. Garibaldi ◽

A. Minuto ◽

M. L. Gullino

Keyword(s):

Verticillium Wilt ◽

Verticillium Dahliae ◽

Vascular Tissue ◽

Disease Incidence ◽

Conidial Suspension ◽

Root Knot Nematode ◽

Solanum Torvum ◽

Meloidogyne Spp ◽

Resistant Rootstock ◽

Low Incidence

Eggplant cultivars grafted on rootstocks resistant to root-knot nematodes (Meloidogyne spp.) are increasingly grown in Italy to reduce nematode infection. During the winter of 2003-2004, eggplants (cv Black Bell and Mirabell) grafted on the nematode-resistant rootstock Solanum torvum were observed with symptoms of a wilt disease in several greenhouses in Sicily (southern Italy). The vascular tissue in stems of affected plants appeared brown. These plants were stunted and developed yellow leaves with brown or black streaks in the vascular tissue. The wilt appeared in several greenhouses at a very low incidence (0.01 to 0.05%). Later, during the fall of 2004, disease incidence was approximately ten times greater in the same greenhouses on new crops. Verticillium dahliae was consistently and readily isolated from symptomatic vascular tissue of the rootstock (S. torvum) and the scion (cv Black bell) when cultured on potato dextrose agar (PDA) (1). Healthy, 50-day-old plants of S. torvum and eggplant (cv. Black Bell) were separately inoculated by root dip with a conidial suspension (1 × 107 CFU/ml) of two isolates of V. dahliae obtained from the rootstock and the scion of the infected grafted plants and with a known pathogenic isolate of V. dahliae from nongrafted eggplant. Noninoculated S. torvum and eggplant served as control treatments. Plants (30 per treatment) were grown in a glasshouse at temperatures ranging between 12 and 41°C (weekly average 15 to 36°C) and relative humidity ranging between 36 and 99% (weekly average 54 to 95%). The first wilt symptoms and vascular discoloration in the roots, crowns, and veins developed 26 and 21 days after inoculation on S. torvum and eggplant, respectively. Seventy-two days after inoculation, 20, 26, and 27% of S. torvum plants and 97, 100, and 87% of the eggplants showed symptoms caused by V. dahliae isolates obtained from the scion of diseased grafted plants, the rootstock of diseased grafted plants, and nongrafted eggplants, respectively. Noninoculated plants remained healthy. To our knowledge, this is the first report in Italy of Verticillium wilt on eggplant grafted on S. torvum rootstocks under commercial conditions. Use of eggplant grafted on the nematode-resistant rootstock of S. torvum presents an interesting opportunity to control the root-knot nematode but has to be carefully considered when dealing with soils severely infested by V. dahliae. Reference: (1) G. F. Pegg and B. L. Brady. Verticillium Wilts. CABI Publishing, Wallingford, UK, 2002.

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First Report of Fusarium oxysporum f. sp. lycopersici Race 3 on Tomato in Tennessee

Plant Disease ◽

10.1094/pdis.2001.85.7.802d ◽

2001 ◽

Vol 85 (7) ◽

pp. 802-802 ◽

Cited By ~ 3

Author(s):

S. C. Bost

Keyword(s):

Fusarium Oxysporum ◽

Fusarium Wilt ◽

Root Rot ◽

Vascular Tissue ◽

Light Conditions ◽

Fresh Market ◽

Race 1 ◽

Causal Fungus ◽

Major Producer ◽

Crown And Root Rot

In the summer of 2000, tomato (Lycopersicon esculentum Mill.) plants in several commercial fields in southeastern and eastern Tennessee exhibited symptoms of Fusarium wilt. All cultivars on which symptoms were observed are classified as resistant to races 1 and 2 of the causal fungus, Fusarium oxysporum Schlechtend.:Fr. f. sp. lycopersici (Sacc.) W.C. Snyder and H.N. Hansen. Race 3 has been reported from several areas (1), but not from Tennessee, a major producer of fresh market tomatoes. F. oxysporum was consistently isolated from discolored vascular tissue on potato dextrose agar (PDA). Pathogenicity and race determination tests for six isolates representing three counties were conducted by inoculating cultivars susceptible to races 1, 2, and 3 (Rutgers); resistant to race 1 (Bradley, Roma VF); resistant to races 1 and 2 (Conquest, Florida 47); or resistant to races 1, 2, and 3 (Floralina). Inoculum suspensions were obtained from 1-week-old cultures grown on PDA. Seedlings were grown in commercial potting mix for 3 weeks. The roots were rinsed and submerged for 30 s in inoculum suspensions (1 × 107 conidia per ml). Seedlings were then transplanted into potting mix in metal flats and placed in a greenhouse. Natural light conditions provided a 12-h photoperiod, and day and night temperatures averaged 29 and 17°C, respectively. Within 4 weeks after inoculation, all isolates caused symptoms of Fusarium wilt in all cultivars except Floralina, indicating that the isolates were race 3. The pathogen was reisolated from the discolored vascular tissue of diseased plants. Among the cultivars most severely affected by all six isolates was Conquest, which is resistant to F. oxysporum f. sp. radicis-lycopersici, the cause of Fusarium crown and root rot. Reference: (1) M. L. Marlatt et al. Plant Dis. 80:1336, 1996.

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Australian papaya dieback: evidence against the calcium deficiency hypothesis and observations on the significance of laticifer autofluorescence

Australian Journal of Agricultural Research ◽

10.1071/ar9960371 ◽

1996 ◽

Vol 47 (3) ◽

pp. 371 ◽

Cited By ~ 8

Author(s):

M Aleemullah ◽

KB Walsh

Keyword(s):

Vascular Tissue ◽

Critical Concentration ◽

Calcium Content ◽

Calcium Deficiency ◽

Secondary Symptom ◽

Phloem Tissue ◽

Severe Problem ◽

Leaf Chlorosis ◽

Brown Discoloration ◽

Xylem Elements

The cause of the dieback disorder of Carica papaya (papaya, papaw, or pawpaw) is unknown, although it is a severe problem for the Queensland industry. In this study, tlle progression of morphological and anatomical symptoms during a growing season in Yarwun is documented. Most plants which displayed a brown discoloration of the vascular tissue developed external symptoms. The discoloration initiated in the stem zone which supported leaves, and developed acropetally into the stem apex, and basipetally into the trunk and in part of the root system. The discoloration was autofluorescent under blue or ultraviolet light, and was associated with laticifers in xylem and phloem tissue and in ray parenchyma. Laticifer autofluoresence was not observed in calcium-deficient plants, nor in the browning associated with nematode damage, but this symptom was present in association with tissue damage caused by Amblypelta lutescens (Distant) and in plants suffering root rot. Laticifer discoloration may represent a general stress reaction by the plant. Tyloses developed in xylem elements, associated with the wilting of the crown, following development of leaf chlorosis and the bending of the stem tip. Dieback-affected apical tissues were lower in total calcium content than healthy tissues, but were not below an experimentally determined critical concentration. It is suggested that the low calcium content represents a secondary symptom of the disorder. caused by a tylosis-induced decrease in hydraulic conductivity and consequently in calcium transport.

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Resistance in Peanut Cultivars and Breeding Lines to Three Root-Knot Nematode Species

Plant Disease ◽

10.1094/pdis-92-4-0631 ◽

2008 ◽

Vol 92 (4) ◽

pp. 631-638 ◽

Cited By ~ 4

Author(s):

W. B. Dong ◽

C. C. Holbrook ◽

P. Timper ◽

T. B. Brenneman ◽

Y. Chu ◽

...

Keyword(s):

Durable Resistance ◽

Nematode Species ◽

Nematode Resistance ◽

Root Knot Nematode ◽

Sources Of Resistance ◽

Breeding Lines ◽

Sequence Characterized Amplified Region ◽

Race 1 ◽

Meloidogyne Spp ◽

Peanut Cultivars

Three major species of root-knot nematode infect peanut: Meloidogyne arenaria race 1, M. hapla, and M. javanica race 3. Sources of resistance to all three nematodes are needed for developing novel peanut cultivars with broad resistance to Meloidogyne spp. Cultivars and breeding lines of peanut were evaluated for resistance to M. arenaria, M. hapla, and M. javanica in the greenhouse and in the laboratory. Twenty-six genotypes with some resistance to M. arenaria, M. javanica, or M. hapla were identified from 60 accessions based on average eggs per gram of root and gall index relative to a susceptible control. Among these, 14 genotypes were moderately to highly resistant to all three species, 5 genotypes were resistant to M. arenaria and M. javanica, 2 genotypes were resistant to M. javanica and M. hapla, 1 genotype was resistant M. arenaria alone, and 4 genotypes were resistant to M. hapla alone. Reproduction of M. arenaria on lines NR 0817, C724-19-11, and D108 was highly variable, indicating that these genotypes likely were heterogeneous for resistance. COAN, NemaTAM, C724-25-8, and the M. arenaria-resistant plants of C724-19-11 contained the dominant sequence-characterized amplified region marker (197/909) for nematode resistance. Results with the molecular markers indicate that the high resistance to M. arenaria in GP-NC WS 6 may be different from the resistance in COAN, NemaTAM, and C724-25-8. Resistance to M. arenaria was correlated with resistance to M. javanica in peanut, whereas resistance to M. hapla was not correlated with the resistance to either M. arenaria or M. javanica. The resistant selections should be valuable sources for pyramiding resistance genes to develop new cultivars with broad and durable resistance to Meloidogyne spp.

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Nematode-Induced Syncytium--A Multinucleate Transfer Cell

Journal of Cell Science ◽

10.1242/jcs.10.3.789 ◽

1972 ◽

Vol 10 (3) ◽

pp. 789-809 ◽

Cited By ~ 1

Author(s):

M. G. K. JONES ◽

D. H. NORTHCOTE

Keyword(s):

Vascular Tissue ◽

Transfer Cell ◽

Cellulose Microfibrils ◽

Xylem Parenchyma ◽

Root Cortex ◽

Feeding Site ◽

A Cell ◽

Xylem Elements ◽

Heterodera Rostochiensis ◽

Cell Alterations

The formation and structure of a syncytium induced by the potato cyst-nematode (Heterodera rostochiensis Woll.) in potato roots is described. At the permanent feeding site of the nematode larva, usually in the root cortex, the larva pierces a cell with its mouth stylet and injects saliva. Cell wall dissolution occurs to incorporate neighbouring cells into a syncytium. A column of cells is incorporated towards the vascular tissue. Centripetal advance is limited by the lignifled xylem, then syncytial spread continues laterally along xylem parenchyma and pericycle cells. Wall protuberances form on syncytial walls adjacent to conducting elements. This indicates the syncytium is a multinucleate transfer cell, and by ingesting syncytial contents the larva is the nutrient sink. As syncytial expansion occurs, sieve elements are crushed and probably cease to function, hence protuberance development continues only against xylem elements. Cell alterations on incorporation into the syncytium involve expansion, loss of cell vacuole, nuclear hypertrophy and a proliferation of cytoplasmic organelles free to move through wall gaps into the communal cytoplasm. ‘Boundary formations’ and microtubules are associated with the growing ends of protuber ances, and appear to be involved in their synthesis. Fibrillar material, possibly cellulose microfibrils, occurs between the plasrnalemma and the membrane of the ‘boundary formation’, and the forming protuberance. To induce the formation of the syncytium, the larva controls the differentiation of unspecialized cells to cells with a specific physiological function. The occurrence of wall protuberances suggests that transfer cells form as a response to solute flow.

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Tetramethylpyrazine Attenuates the Endotheliotoxicity and the Mitochondrial Dysfunction by Doxorubicin via 14-3-3γ/Bcl-2

Oxidative Medicine and Cellular Longevity ◽

10.1155/2019/5820415 ◽

2019 ◽

Vol 2019 ◽

pp. 1-20 ◽

Cited By ~ 2

Author(s):

Bin Yang ◽

Hongwei Li ◽

Yang Qiao ◽

Qing Zhou ◽

Shuping Chen ◽

...

Keyword(s):

Cell Viability ◽

Vascular Endothelium ◽

Caspase 3 ◽

Vascular Tissue ◽

Ros Generation ◽

Protective Effects ◽

Histopathological Changes ◽

Mptp Opening

Doxorubicin (Dox) with cardiotoxicity and endotheliotoxicity limits its clinical application for cancer. The toxicitic mechanism involves excess ROS generation. 14-3-3s have the protective effects on various injured tissues and cells. Tetramethylpyrazine (TMP) is an alkaloid extracted from the rhizome of Ligusticum wallichii and has multiple bioactivities. We hypothesize that TMP has the protective effects on vascular endothelium by upregulating 14-3-3γ. To test the hypothesis, Dox-induced endotheliotoxicity was used to establish vascular endothelium injury models in mice and human umbilical vein endothelial cells. The effects of TMP were assessed by determining thoracic aortic strips’ endothelium-dependent dilation (EDD), as well as LDH, CK, caspase-3, SOD, CAT, GSH-Px activities and MDA level in serum, apoptotic rate, and histopathological changes of vascular tissue (in vivo). Also, cell viability, LDH and caspase-3 activities, ROS generation, levels of NAD+/NADH and GSH/GSSG, MMP, mPTP opening, and apoptotic rate were evaluated (in vitro). The expression of 14-3-3γ and Bcl-2, as well as phosphorylation of Bad (S112), were determined by Western blot. Our results showed that Dox-induced injury to vascular endothelium was decreased by TMP via upregulating 14-3-3γ expression in total protein and Bcl-2 expression in mitochondria, activating Bad (S112) phosphorylation, maintaining EDD, reducing LDH, CK, and caspase-3 activities, thereby causing a reduction in apoptotic rate, and histopathological changes of vascular endothelium (in vivo). Furthermore, TMP increased cell viability and MMP levels, maintained NAD+/NADH, GSH/GSSG balance, decreased LDH and caspase-3 activities, ROS generation, mPTP opening, and apoptotic rate (in vitro). However, the protective effects to vascular endothelium of TMP were significantly canceled by pAD/14-3-3γ-shRNA, an adenovirus that caused knockdown 14-3-3γ expression, or ABT-737, a specific Bcl-2 inhibitor. In conclusion, this study is the first to demonstrate that TMP protects the vascular endothelium against Dox-induced injury via upregulating 14-3-3γ expression, promoting translocation of Bcl-2 to the mitochondria, closing mPTP, maintaining MMP, inhibiting RIRR mechanism, suppressing oxidative stress, improving mitochondrial function, and alleviating Dox-induced endotheliotoxicity.

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