Defects of helicity and motility in the corn stunt spiroplasma, Spiroplasma kunkelii

1989 ◽  
Vol 35 (12) ◽  
pp. 1087-1091
Author(s):  
I.-M. Lee ◽  
R. E. Davis
Keyword(s):  
Cell Shape ◽  
Agar Medium ◽  
Polyacrylamide Gel Electrophoresis ◽  
Broth Culture ◽  
Serum Free Medium ◽  
Primary Isolation ◽  
Spiroplasma Kunkelii ◽  
Corn Stunt ◽  
Corn Stunt Spiroplasma ◽  
Corn Plants

Serum-free medium LD59 was used for primary isolation of Spiroplasma kunkelii (corn stunt spiroplasma) from diseased corn plants from Mississippi. Several strains were cloned in triplicate from one primary pure culture. Some of the strains were helical in cell shape, some were nonhelical, and some were partially helical, consisting of helical and nonhelical regions in the same cell. All helical strains except one (strain I-15) exhibited flexional and rotational motility in broth culture. Partially helical strains exhibited rotational movement in helical regions only. Nonhelical cells exhibited only flexional motility. These three morphological types produced three colony types on medium LD59 solidified with 0.8% agar. Nonhelical strains produced minute "fried egg" colonies (≤ 0.2 mm in diameter after 20 days incubation), while partially helical strains produced small colonies with granular centers surrounded by satellite colonies. Strains with normal helicity in general produced large, uniformly diffuse colonies (up to 2 mm), but one helical strain (I-15) appeared to be nonmotile in broth culture and to exhibit little translational motility in agar medium, accounting for development of minute granular colonies (about 0.2 mm in diameter). All new strains were serologically closely related to known strains of S. kunkelii, but polyacrylamide gel electrophoresis analysis of membrane proteins revealed minor differences. This is the first report of nonhelical strains of S. kunkelii and of helical strains with apparent impairment in translational motility.Key words: Spiroplasma kunkelii, nonhelical spiroplasmas, Mollicutes.

Serum-free media for cultivation of spiroplasmas

1989 ◽  
Vol 35 (12) ◽  
pp. 1092-1099 ◽  
Author(s):  
I.-M. Lee ◽  
R. E. Davis
Keyword(s):  
Good Growth ◽  
Supporting Capacity ◽  
Spiroplasma Citri ◽  
Serum Free ◽  
Spiroplasma Kunkelii ◽  
Corn Stunt ◽  
Agar Media ◽  
Corn Stunt Spiroplasma ◽  
Free Media ◽  
Mycoplasma Spp

Serum-free media that contained bovine serum albumin and lipids (fatty acids, cholesterol, phosphatidic acid, and phospholipids) to replace serum were formulated for the culture of some fastidious strains of corn stunt spiroplasma, Spiroplasma kunkelii. These media also supported good growth of other spiroplasmas, including epiphytic, entomopathogenic, and phytopathogenic strains. The growth rates attained in these serum-free media were comparable to those in media which contained serum. The serum-free broth and agar media were of major importance for culture of several fastidious strains of corn stunt spiroplasma because the serum-containing media supported little, if any, of their growth. Colonies of these fastidious strains were readily formed on serum-free agar media in aerobic, candle jar, and anaerobic environments, but were not readily formed on the serum-containing media. The serum-free media were less subject to deterioration during storage or incubation, and the growth-supporting capacity of serum-free media diminished more slowly than that of serum-containing media.Key words: Spiroplasma kunkelii, Spiroplasma citri, Mollicutes, Mycoplasma spp. culture, entomopathogens.

EUDORYLAS (METADORYLAS) SP. (DIPTERA: PIPUNCULIDAE): A PREVIOUSLY UNREPORTED PARASITOID OF DALBULUS MAIDIS (DELONG AND WOLCOTT) AND DALBULUS ELIMATUS (BALL) (HOMOPTERA: CICADELLIDAE)

1991 ◽  
Vol 123 (1) ◽  
pp. 241-242 ◽  
Author(s):  
Fernando E. Vega ◽  
Pedro Barbosa ◽  
Alejandro Perez Panduro
Keyword(s):  
Latin America ◽  
Natural Enemies ◽  
Central Mexico ◽  
Dalbulus Maidis ◽  
Spiroplasma Kunkelii ◽  
Corn Stunt ◽  
Corn Stunt Spiroplasma ◽  
Maize Rayado Fino Virus ◽  
Corn Leafhopper

The genus Dalbulus (Homoptera: Cicadellidae) consists of 11 species, 10 of which can be found in México (Nault 1990). Some members in the genus, such as the corn leafhopper, Dalbulus maidis (DeLong and Wolcott), and the Mexican corn leafhopper, Dalbulus elimatus (Ball) are serious pests of maize due to their transmission of three corn stunting pathogens: corn stunt spiroplasma (CSS; Spiroplasma kunkelii Whitcomb et al.), maize bushy stunt mycoplasmalike organism (MBSM), and maize rayado fino virus (MRFV) (Nault 1990). Due to the widespread damage that these leafhopper-vectored pathogens cause in maize-growing regions in Latin America, a search for the leafhopper natural enemies was conducted in maize agroecosystems in central México.

scholarly journals Corn Stunt Disease: An Ideal Insect–Microbial–Plant Pathosystem for Comprehensive Studies of Vector-Borne Plant Diseases of Corn

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 747
Author(s):  
Tara-kay L. Jones ◽  
Raul F. Medina
Keyword(s):  
Pest Control ◽  
Plant Diseases ◽  
Insect Vector ◽  
Ongoing Research ◽  
Severe Stunting ◽  
Vector Borne Diseases ◽  
Spiroplasma Kunkelii ◽  
Corn Stunt ◽  
Vector Borne ◽  
Corn Plants

Over 700 plant diseases identified as vector-borne negatively impact plant health and food security globally. The pest control of vector-borne diseases in agricultural settings is in urgent need of more effective tools. Ongoing research in genetics, molecular biology, physiology, and vector behavior has begun to unravel new insights into the transmission of phytopathogens by their insect vectors. However, the intricate mechanisms involved in phytopathogen transmission for certain pathosystems warrant further investigation. In this review, we propose the corn stunt pathosystem (Zea mays–Spiroplasma kunkelii–Dalbulus maidis) as an ideal model for dissecting the molecular determinants and mechanisms underpinning the persistent transmission of a mollicute by its specialist insect vector to an economically important monocotyledonous crop. Corn stunt is the most important disease of corn in the Americas and the Caribbean, where it causes the severe stunting of corn plants and can result in up to 100% yield loss. A comprehensive study of the corn stunt disease system will pave the way for the discovery of novel molecular targets for genetic pest control targeting either the insect vector or the phytopathogen.

scholarly journals Aspectos da biologia da cigarrinha-do-milho, Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae)

1999 ◽  
Vol 28 (3) ◽  
pp. 413-420 ◽  
Author(s):  
José M. Waquil ◽  
Paulo A. Viana ◽  
Ivan Cruz ◽  
Jamilton P. Santos
Keyword(s):  
Dalbulus Maidis ◽  
Spiroplasma Kunkelii ◽  
Corn Stunt ◽  
Corn Stunt Spiroplasma ◽  
Maize Bushy Stunt Phytoplasma ◽  
Maize Rayado Fino Virus

Na cultura do milho, a cigarrinha, Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae) é vetora de três patógenos: Spiroplasma kunkelii (corn stunt spiroplasma), o fitoplasma do milho (maize bushy stunt phytoplasma) e o vírus da risca do milho (maize rayado fino vírus). Os prejuízos causados por essas doenças podem variar de nove a 90 %, dependendo da susceptibilidade das cultivares e dos patógenos envolvidos. O objetivo deste trabalho foi estudar aspectos da biologia de D. maidis, sob condições controladas e utilizando-se insetos e cultivares de milho e sorgo adaptados às condições brasileiras. Plântulas de milho e de sorgo foram cultivadas em vasos plásticos, cobertas com gaiolas de plástico e infestadas com 10 adultos por planta. Sempre utilizando-se 10 plântulas por tratamento, foram conduzidos dois ensaios independentes. No 1°, estudou-se o período de incubação nas temperaturas constantes de 17, 20, 23, 26, 29 e 32ºC ± 1ºC e fotofase de 12 h. No 2°, estudou-se o desenvolvimento de ninfas à temperatura constante de 26,5 ± 2ºC e mesma fotofase. O período de incubação foi mais curto nas temperaturas de 26 e 29ºC, nas quais cerca de 70% das ninfas levaram nove dias para a eclosão. Foram observados até cinco ínstares, embora cerca de 76% da população tenha completado o desenvolvimento passando por apenas quatro ínstares. A duração média de cada instar foi de 3,14 dias. Os adultos viveram em média 51,4 dias e o ciclo médio de ovo a adulto foi de 26,3 dias. Portanto, para a manutenção de colônias de insetos ou no desenvolvimento de estudos com essa espécie é importante observar os limites máximos e mínimos de temperatura.

Physical and genetic map of the Spiroplasma kunkelii CR2-3x chromosome

2006 ◽  
Vol 52 (9) ◽  
pp. 857-867 ◽  
Author(s):  
Ellen L Dally ◽  
Thereza S.L Barros ◽  
Yan Zhao ◽  
ShaoPing Lin ◽  
Bruce A Roe ◽  
...  
Keyword(s):  
Genetic Map ◽  
Gel Electrophoresis ◽  
Southern Hybridization ◽  
Pulsed Field Gel Electrophoresis ◽  
Enzyme Analysis ◽  
Two Dimensional ◽  
Pulsed Field ◽  
Spiroplasma Kunkelii ◽  
Corn Stunt ◽  
Physical And Genetic Map

Spiroplasma kunkelii (class Mollicutes) is the characteristically helical, wall-less bacterium that causes corn stunt disease. A combination of restriction enzyme analysis, pulsed-field gel electrophoresis (PFGE), and Southern hybridization analysis was used to construct a physical and genetic map of the S. kunkelii CR2-3x chromosome. The order of restriction fragments on the map was determined by analyses of reciprocal endonuclease double digests employing I-CeuI, AscI, ApaI, EagI, SmaI, BssHII, BglI, and SalI; adjacent fragments were identified on two-dimensional pulsed-field electrophoresis gels. The size of the chromosome was estimated at 1550 kb. Oligonucleotide pairs were designed to prime the amplification of 26 S. kunkelii gene sequences in the polymerase chain reaction (PCR). Using PCR amplicons as probes, the locations of 27 S. kunkelii putative single-copy genes were positioned on the map by Southern hybridization analyses of chromosomal fragments separated in PFGE. The nucleotide sequence of the single ribosomal RNA operon was determined and its location mapped to a chromosomal segment bearing recognition sites for SalI, SmaI, EagI, and I-CeuI.Key words: Spiroplasma kunkelii CR2-3x, corn stunt spiroplasma, mollicutes, genome mapping, two-dimensional pulsed-field gel electrophoresis.

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