Plasmodesmata play pivotal role in sucrose supply to Meloidogyne graminicola ‐caused giant cells in rice

Meloidogyne graminicola causes significant damage to rice fields worldwide. Sources of resistance to M. graminicola reported in Oryza sativa are limited. Resistance to this species has been found in other Oryza species such as O. glaberrima and O. longistaminata. This study aimed to evaluate the reaction of four wild species of Oryza from the Embrapa Rice and Bean Germplasm Bank (Goiás, Brazil) to a pool of M. graminicola populations and determine the resistance mechanism in O. glumaepatula. Two genotypes of O. glaberrima, one of O. alta, three of O. glumaepatula, one of O. grandiglumis, one of O. longistaminata, and one of O. sativa (control) were included in the study. The results showed that O. glumaepatula was highly resistant (reproduction factor [RF] < 1). O. glaberrima, O. alta, and O. grandiglumis were considered moderately resistant. O. longistaminata was susceptible, although values of RF remained lower than the control O. sativa ‘BR-IRGA 410’, considered highly susceptible. Histological observations on the interaction of O. glumaepatula and M. graminicola showed reduced penetration of second-stage juveniles (J2s) when this resistant wild accession was compared with O. sativa. An intense hypersensitivity response-like reaction occurred at 2 days after inoculation in the root cortex of the resistant accession. Few J2s established in the central cylinder, and rare collapsed giant cells were observed surrounded by degenerate females. Fluorescence microscopy in O. glumaepatula revealed giant cells and the female body presumably exhibiting accumulation of phenolic compounds. Our study suggests that wild rice accessions, especially from the AA genotype (e.g., O. glumaepatula), are of great interest for use in future breeding programs with Oryza spp.

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Potassium Sulphate Induces Resistance of Rice against the Root-Knot Nematode Meloidogyne graminicola

10.21203/rs.3.rs-225061/v1 ◽

2021 ◽

Author(s):

Mao-Yan Liu ◽

De-Liang Peng ◽

Wen Su ◽

Chao Xiang ◽

Jin-Zhuo Jian ◽

...

Keyword(s):

Induced Resistance ◽

Giant Cells ◽

Parasitic Nematodes ◽

Wild Type ◽

Potassium Fertilizer ◽

Root Knot Nematode ◽

Callose Deposition ◽

Meloidogyne Graminicola ◽

K Fertilizer ◽

In The Wild

Abstract Background Potassium (K), an important nutrient element, can improve the stress resistance/tolerance of crops. The application of K in resisting plant parasitic nematodes shows that the K treatment can effectively reduce the occurrence of nematode diseases and increase crop yield. However, data on K2SO4 induced rice resistance to Meloidogyne graminicola are still lacking. To evaluate rice resistance against M. graminicola induced by K2SO4 and to further clarify its mechanism is essential for the rational use of K fertilizer to ensure the safety of rice production.Results In this work, K2SO4 treatment effectively reduced the numbers of both galls and nematodes in rice roots, and delayed the development of nematodes to the adult stage. Rather than by affecting the attractiveness of roots to nematodes and the morphological phenotype of giant cells at feeding sites, such effect was achieved by rapidly stimulating hydrogen peroxide (H2O2) accumulation, increasing callose deposition. Meanwhile, such induced resistance required the active participation of the potassium channel OsAKT1 and the potassium transporter OsHAK5. The numbers of both galls and nematodes were higher in both gene deficient plants than that in the wild-type plants, and the K2SO4-induced resistance showed weaker in the defective plants than in the wild-type plants.Conclusions K2SO4 treatment effectively induces rice resistance to root-knot nematode M. graminicola. The mechanism of inducing resistance is to prime the basic defense of rice, up-regulating the expression of resistance-related genes and with the involvement of K+ channel and transporter. These laid a foundation for further study on the mechanism of rice to defense against root-knot nematodes and the effective use of potassium fertilizer to improve rice resistance against nematodes in the field.

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Histopathology of the rice root-knot nematode, Meloidogyne graminicola, on Oryza sativa and O. glaberrima

Nematology ◽

10.1163/15685411-00002746 ◽

2014 ◽

Vol 16 (1) ◽

pp. 73-81 ◽

Cited By ~ 23

Author(s):

Ma. Teodora Nadong Cabasan ◽

Arvind Kumar ◽

Stéphane Bellafiore ◽

Dirk De Waele

Keyword(s):

Early Stage ◽

Management Strategies ◽

Giant Cells ◽

Structural Features ◽

Defence Response ◽

Root Penetration ◽

Oryza Glaberrima ◽

Root Knot Nematode ◽

Meloidogyne Graminicola ◽

Rice Genotypes

The root-knot nematode, Meloidogyne graminicola, can cause substantial rice yield losses. Understanding the mechanisms of resistance to this nematode species in known resistant rice genotypes may help to improve rice genotypes, aiming at developing and implementing environment-friendly and cost-effective nematode management strategies. Using susceptible and resistant rice genotypes, a comparative analysis of histological response mechanisms was made during two phases of the nematode colonisation: i) root penetration; and ii) subsequent establishment and development by M. graminicola second-stage juveniles (J2). Two types of defence response mechanisms could be distinguished in the resistant rice genotypes. The early defence response consisted of a hypersensitive response (HR)-like reaction in the early stage of infection characterised by necrosis of cells directly affected by nematode feeding. This HR-like reaction was observed only in the M. graminicola-resistant Oryza glaberrima genotypes and not in the M. graminicola-susceptible O. sativa genotypes. The late defence response took place after the induction of giant cells by the J2. Giant cells usually collapsed and degenerated before J2 developed into adults. Structural features of the roots of the susceptible O. sativa showed greater root and stele diam. and cortex thickness than the resistant O. glaberrima genotypes. Desired features of plants with resistance to M. graminicola elucidated in this study can be used for selection of plants for breeding programmes.

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Transcriptional analysis through RNA sequencing of giant cells induced by Meloidogyne graminicola in rice roots

Journal of Experimental Botany ◽

10.1093/jxb/ert219 ◽

2013 ◽

Vol 64 (12) ◽

pp. 3885-3898 ◽

Cited By ~ 77

Author(s):

Hongli Ji ◽

Godelieve Gheysen ◽

Simon Denil ◽

Keith Lindsey ◽

Jennifer F. Topping ◽

...

Keyword(s):

Rna Sequencing ◽

Giant Cells ◽

Transcriptional Analysis ◽

Meloidogyne Graminicola ◽

Rice Roots

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Studies of a Defective Measles Virus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100780 ◽

1968 ◽

Vol 26 ◽

pp. 208-209

Author(s):

R. M. McCombs ◽

M. Benyesh-Melnick ◽

J. P. Brunschwig

Keyword(s):

Inclusion Bodies ◽

Measles Virus ◽

Giant Cells ◽

Helical Structures ◽

Thin Sections ◽

Virus Particles ◽

Extracellular Virus ◽

Culture Cells ◽

Infected Cells ◽

Eosinophilic Inclusions

Measles virus is an agent that is capable of replicating in a number of different culture cells and generally causes the formation of multinucleated giant cells. As a result of infection, virus is released from the cells into the culture fluids and reinfection can be initiated by this cell-free virus. The extracellular virus has been examined by negative staining with phosphotungstic acid and has been shown to be a rather pleomorphic particle with a diameter of about 140 mμ. However, no such virus particles have been detected in thin sections of the infected cells. Rather, the only virus-induced structures present in the giant cells are eosinophilic inclusions (intracytoplasmic or intranuclear). These inclusion bodies have been shown to contain helical structures, resembling the nucleocapsid observed in negatively stained preparations.

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Cell-matrix interactions in the early mouse embryo

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123404 ◽

1992 ◽

Vol 50 (1) ◽

pp. 600-601

Author(s):

A.E. Sutherland ◽

P.G. Calarco ◽

C.H. Damsky

Keyword(s):

Mouse Embryo ◽

Giant Cells ◽

Blastocyst Stage ◽

Integrin Subunit ◽

Β1 Integrin ◽

Cell Stage ◽

Early Mouse Embryo ◽

Migratory Activity ◽

Early Mouse ◽

Cell Matrix Interactions

Cell-extracellular matrix (ECM) interactions mediated by the integrin family of receptors are critical for morphogenesis and may also play a regulatory role in differentiation during early development. We have examined the onset of expression of individual integrin subunit proteins in the early mouse embryo, and their roles in early morphogenetic events. As detected by immunoprecipitation, the α6, αV, β1, and β3 subunits are detected as early as the 4-cell stage, α5 at the hatched blastocyst stage and αl and α3 following blastocyst attachment. We tested the role of these integrins in the attachment and migratory activity of two cell populations of the early mouse embryo: the trophoblast giant cells, which invade the uterine stroma and ultimately contribute to the chorio-allantoic placenta, and the parietal endoderm, which migrates over the inner surface of the trophoblast and ultimately forms Reichert's membrane and the parietal yolk sac. Experiments were done in serum-free medium on substrates coated with laminin (Ln) and fibronectin (Fn). Trophoblast outgrowth occurs on Ln and its E8 fragment (long arm), but not on the E1’ fragment (cross region) (Figs. 1, 2 ). This outgrowth is inhibited by anti-E8, anti-Ln, and by the anti-β1 family antiserum anti-ECMR, but not by anti-αV or the function-perturbing GoH3 antibody that recognizes the α6/β1 integrin, a major Ln (E8) receptor. This suggests that trophoblast outgrowth on Ln or E8 is mediated by a different β1 integrin such as α3/β1. Early stages of trophoblast outgrowth (up to 48 hours) on Fn are inhibited by anti-Fn and by function-perturbing anti-αV antibodies, whereas at later times outgrowth becomes insensitive to anti-αV but remains sensitive to the anti-β1 family antiserum anti-ECMr, indicating that trophoblast cells modulate their interaction with Fn during outgrowth. Trophoblast outgrowth on vitronectin (Vn) is sensitive to anti-αV antibodies throughout the 5-day period examined.

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