94
June 1972
Family: Rhabdoviridae
Genus: Nucleorhabdovirus
Species: Maize mosaic virus
Acronym: MMV


Maize mosaic virus

Frieda Herold
Plant Virus Laboratory, Center for Microbiology and Cell Biology, Instituto Venezolano de Investigaciones Científicas, Apartado 1827, Caracas, Venezuela

Contents

Introduction
Main Diseases
Geographical Distribution
Host Range and Symptomatology
Strains
Transmission by Vectors
Transmission through Seed
Transmission by Grafting
Transmission by Dodder
Serology
Nucleic Acid Hybridization
Relationships
Stability in Sap
Purification
Properties of Particles
Particle Structure
Particle Composition
Properties of Infective Nucleic Acid
Molecular Structure
Genome Properties
Satellites
Relations with Cells and Tissues
Ecology and Control
Notes
References
Acknowledgements
Figures

Introduction

Described by Kunkel (1921, 1922, 1927), Herold, Bergold & Weibel (1960), and Herold & Munz (1967a).

Selected synonyms

Corn mosaic virus (Rev. appl. Mycol. 1: 194)
Corn yellow stripe virus (Rev. appl. Mycol. 2: 33)
Corn stripe virus (Rev. appl. Mycol. 7: 159)
Corn virus 1 (Rev. appl. Mycol. 17: 52)
Maize stripe virus (Rev. appl. Mycol. 15: 528)
Marmor zeae (Rev. appl. Mycol. 19: 229)
Zea virus 1 (Rev. appl. Mycol. 17: 52)

A virus with bullet-shaped particles c. 242 x 48 nm in plant sections or c. 225 x 90 nm in leaf dip preparations, known only from Gramineae. It causes a severe disease in maize. Transmitted by the leafhopper Peregrinus maidis in a persistent manner. Occurs in many tropical countries.

Main Diseases

Causes yellow spots and stripes in the leaves, and stunting of the plants of maize and other members of the Gramineae.

Geographical Distribution

Hawaii (Kunkel, 1921), Cuba (Stahl, 1927), Trinidad (Briton-Jones, 1933), Tanzania (Storey, 1933), Puerto Rico (Cook, 1936a, 1936b), Mauritius (Orian, 1954), Surinam (Van Hoof, 1960), Venezuela (Herold, 1963), and presumably India (Cherian & Kylasam, 1936). Probably present in most Caribbean countries.

Host Range and Symptomatology

All plant hosts known are members of the Gramineae. Although principally found in maize, it occurs naturally in Rottboellia exaltata (Van Hoof, 1960) and Setaria vulpiseta (F. Herold, unpublished). It has been transmitted experimentally to Euchlena mexicana (Malaguti, 1963) and Sorghum (F. Herold, unpublished). Not transmissible by inoculation of sap.

Diagnostic species

Zea mays (maize). Susceptible varieties such as Sicarigua or the line Theobromina Blanco develop light green to yellow spots, and interrupted stripes and bands between and along the fine veins (Fig.2); sometimes parts of the leaves appear almost completely yellow. The yellow parts may become necrotic. Sheaths, stalks and husks also may show yellow stripes and spots. Depending on the age of the plant at the time of infection, all or only the upper internodes are shortened. Often the head of the plant bends over to one side (Fig.1). Symptoms appear from 4 days to 7 weeks after inoculation and are first visible at the leaf bases.

Propagation species

Zea mays, susceptible varieties.

Assay species

Zea mays, susceptible varieties.

Strains

Isolates from maize seem identical, but a strain from Rottboellia exaltata (Van Hoof, 1960) may be distinct.

Transmission by Vectors

Transmitted by the leafhopper, Peregrinus maidis, nymphs and adults, males and females; about 5% (Herold, 1963) to 23% (Carter, 1941) of a natural population are able to transmit. Acquisition access time 1 day or less, incubation period between 11 days and 7 weeks; persistent, but transmitted only intermittently. The virus multiplies in the insect (Herold & Munz, 1965). The transmission capacity of P. maidis seems to be influenced by the presence of the latent Peregrinus virus (Herold & Munz, 1967b): in colonies of P. maidis from Hawaii and Venezuela, containing no or very little Peregrinus virus respectively, twice as many individuals transmitted maize mosaic virus as in colonies from Venezuela containing very much Peregrinus virus (F. Herold, unpublished).

Transmission through Seed

None reported.

Transmission by Dodder

No information.

Serology

The virus is weakly immunogenic. Antisera with titres of 1/4 have been obtained by injecting guinea pigs with partially purified virus from plant sap. Precipitation was observed in immunodiffusion tests with crude sap from diseased plants but not from healthy ones. In chloroplast agglutination and microprecipitation tests, no reaction was noted (F. Herold, unpublished).

Relationships

Morphologically the virus resembles animal viruses of the rhabdovirus group. Among plant viruses of this type it resembles clover enation, eggplant mottled dwarf, lettuce necrotic yellows, potato yellow dwarf, rice transitory yellowing, sowthistle yellow vein and wheat striate mosaic viruses in its association with nuclear membranes. Antiserum to lettuce necrotic yellows virus did not react with maize mosaic virus in crude maize sap.

Stability in Sap

Crude leaf sap diluted 1/10 in 0.01 M phosphate buffer pH 7.5, and partially purified preparations were still infective after 24 and 48 hr respectively at 4°C as shown by injection of Peregrinus maidis (F. Herold, unpublished).

Purification

No satisfactory purification procedure has been developed. Methods involving differential centrifugation, fluorocarbon treatment (Herold et al., 1960) or sucrose density gradient centrifugation were only partially successful (F. Herold, unpublished).

Properties of Particles

No information.

Particle Structure

Particles are bullet-shaped (Fig.3, Fig.5) or bacilliform (Fig.6), c. 225 x 90 nm in negatively stained dip preparations or 242 x 48 nm in plant sections. Particles consist of an envelope with thread- or knob-like protrusions (Fig.5, Fig.7, Fig.8) enclosing a helical structure with a pitch of 4.5 nm, and 35 units per turn. Inside the helical structure there appears to be a central core which in some particles appears homogeneous and in others consists of spherical masses (Herold & Munz, 1967a).

Particle Composition

No information.

Relations with Cells and Tissues

Epidermal, palisade and parenchyma cells of leaves show cytoplasmic inclusions surrounding the nucleus and distributed throughout the cell (Herold et al., 1960). These inclusions consist of three-dimensional crystalline arrays of virus particles (Fig.4). Particles bud at the inner nuclear membrane (Fig.3) and accumulate in the perinuclear space (F. Herold, unpublished). Particles can also be observed in the stamens of male flowers. In cells of the salivary gland and intestine of Peregrinus maidis, particles are found singly and in groups in the perinuclear space, and in tubules and cisternae of the endoplasmic reticulum (Herold & Munz, 1965).

Notes

The disease called ‘freckled yellow’ of sorghum may also be caused by maize mosaic virus because the symptoms in sorghum resemble those caused by maize mosaic virus in maize; the disease agent was transmitted from sorghum to sorghum by Peregrinus maidis, and maize growing near infected sorghum exhibited the same symptoms (Cherian & Kylasam, 1936). Moreover, maize mosaic virus can be transmitted experimentally from maize to sorghum and vice versa (F. Herold, unpublished).

Other diseases which maybe confused with maize mosaic because of similarity of leaf symptoms are maize stunt and maize streak. However, neither of these disease agents have bullet-shaped particles nor are they transmitted by P. maidis; maize stunt is associated with a mycoplasma-like organism.

References

  1. Briton-Jones, Trop. Agric. Trin. 10: 119, 1933.
  2. Carter, Ann. ent. Soc. Am. 34: 551, 1941.
  3. Cook, J. Agric. Univ. P. Rico 20: 681, 1936a.
  4. Cook, J. Agric. Univ. P. Rico 20: 685, 1936b.
  5. Cherian & Kylasam, Proc. Ass. econ. Biol., Coimbatore 4: 57, 1936.
  6. Herold, Acta cient. venez. 14, Suppl. 1: 221, 1963.
  7. Herold & Munz, Virology 25: 412, 1965.
  8. Herold & Munz, J. gen. Virol. 1: 227, 1967a.
  9. Herold & Munz, J. Virol. 1: 1028, 1967b.
  10. Herold, Bergold & Weibel, Virology 12: 335, 1960.
  11. Kunkel, Bull. Hawaiian Sug. Plrs' Ass. Exp. Stn Bot. Ser. 3: 44, 1921.
  12. Kunkel, Hawaii. Plrs' Rec. 26: 58, 1922.
  13. Kunkel, Phytopathology 17: 41, 1927.
  14. Malaguti, Agronomía trop. 12: 175, 1963.
  15. Orian, Rev. appl. Mycol. 34: 107, 1954.
  16. Stahl, Bull. trop. Pl. Res. Fdn 7: 3, 1927.
  17. Storey, Rep. E. Afr. agric. Res. Inst., 1932/33: 13, 1933.
  18. Van Hoof, Surin. Landb. 8: 20, 1960.


Figure 1

Infected maize plant.

Figure 2

Spots and stripes in an infected maize leaf.

Figure 3

Section of infected maize leaf showing particles budding at the nuclear membrane. Bar represents 200 nm.

Figure 4

Section of infected maize leaf showing the crystalline array of virus particles. Bar represents 200 nm.

Figure 5

Bullet-shaped particle showing the envelope protrusions, helical structure, and central core which in this particle appears homogeneous. Stained with phosphotungstate. Bar represents 50 nm.

Figure 6

Bacilliform virus particle. Stained with phosphotungstate. Bar represents 50 nm.

Figure 7

Partly disintegrated particle with partly uncoiled helical structure. Stained with uranyl acetate. Bar represents 50 nm.

Figure 8

Virus particle showing the helical structure with subunits. Stained with phosphotungstate. Bar represents 50 nm.