Enabling mycelial application of Hirsutella thompsonii for managing the coconut mite

Abstract Ribotoxins are cytotoxic members of the family of fungal extracellular ribonucleases best represented by RNase T1. They share a high degree of sequence identity and a common structural fold, including the geometric arrangement of their active sites. However, ribotoxins are larger, with a well-defined N-terminal β-hairpin, and display longer and positively charged unstructured loops. These structural differences account for their cytotoxic properties. Unexpectedly, the discovery of hirsutellin A (HtA), a ribotoxin produced by the invertebrate pathogen Hirsutella thompsonii, showed how it was possible to accommodate these features into a shorter amino acid sequence. Examination of HtA N-terminal β-hairpin reveals differences in terms of length, charge, and spatial distribution. Consequently, four different HtA mutants were prepared and characterized. One of them was the result of deleting this hairpin [Δ(8-15)] while the other three affected single Lys residues in its close spatial proximity (K115E, K118E, and K123E). The results obtained support the general conclusion that HtA active site would show a high degree of plasticity, being able to accommodate electrostatic and structural changes not suitable for the other previously known larger ribotoxins, as the variants described here only presented small differences in terms of ribonucleolytic activity and cytotoxicity against cultured insect cells.

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Microcycle conidiation in Hirsutella thompsonii

Canadian Journal of Microbiology ◽

10.1139/m88-103 ◽

1988 ◽

Vol 34 (5) ◽

pp. 625-630 ◽

Cited By ~ 6

Author(s):

J. P. Latgé ◽

R. L. Cabrera Cabrera ◽

M. C. Prévost

Keyword(s):

Electron Microscopy ◽

Batch Culture ◽

Submerged Culture ◽

Morphological Changes ◽

Hirsutella Thompsonii ◽

Microcycle Conidiation

A fermenter method for producing conidiospores of the acarine pathogen, Hirsutella thompsonii, was developed using a strain able to produce microcycle conidiation in submerged culture. The morphological changes occurring during microcycle formation were followed under electron microscopy. Growth and sporulation patterns of the fungus were examined in batch culture. An average of 2–5 × 108 spores/mL was obtained after 3 days of growth.

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Hirsutella thompsonii a fungal parasite of the citrus rust mitePhyllocoptruta oleivora in the Rio Grande Valley of Texas

Entomophaga ◽

10.1007/bf02372778 ◽

1974 ◽

Vol 19 (4) ◽

pp. 431-436 ◽

Cited By ~ 6

Author(s):

B. Villalon ◽

H. A. Dean

Keyword(s):

Rio Grande Valley ◽

Rio Grande ◽

Fungal Parasite ◽

Hirsutella Thompsonii

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Coconut destiny after the invasion of Aceria guerreronis (Acari: Eriophyidae) in India*

Zoosymposia ◽

10.11646/zoosymposia.6.1.26 ◽

2011 ◽

Vol 6 (1) ◽

pp. 160-169 ◽

Cited By ~ 4

Author(s):

M. A. HAQ

Keyword(s):

Management Practices ◽

Critical Assessment ◽

Bakery Products ◽

Aceria Guerreronis ◽

Agricultural Income ◽

Northern India ◽

Coconut Mite ◽

Farming Community ◽

The People ◽

Considerable Damage

The coconut mite, Aceria guerreronis Keifer, has emerged as a common menace to most of the coconut plantations in India. After its first upsurge in Kerala at the end of the 1990´s, the mite has spread to many states in southern and northern India, causing considerable damage. Coconut provides one third of the agricultural income in the regions in which it is grown and more than 10 million people are dependent on this cash crop directly or indirectly through coconut-based industries like coir, copra, oil, honey, furniture, handicrafts, beverages, bakery products and so on. The economic instability of the coconut farming community and the people employed in coconut-based industries rank the highest order. A critical assessment of the various problems created by A. guerreronis in the agricultural economy of India is presented in order to supplement data on crop loss through nut malformation, nut fall, loss in fibre and copra. Varietal differences in susceptibility of the plant and future strategies in terms of management practices for an early control of the mite are discussed, and suggestions for future activities to alleviate mite damage are presented.

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SUSCETIBILIDADE DE NINFAS DE DIAPHORINA CITRI A FUNGOS ENTOMOPATOGÊNICOS

Arquivos do Instituto Biológico ◽

10.1590/1808-1657v76p2972009 ◽

2009 ◽

Vol 76 (2) ◽

pp. 297-302

Author(s):

L.F.L. Padulla ◽

S.B Alves

Keyword(s):

Beauveria Bassiana ◽

Metarhizium Anisopliae ◽

Paecilomyces Fumosoroseus ◽

Diaphorina Citri ◽

Murraya Paniculata ◽

Hirsutella Thompsonii

RESUMO Avaliou-se a patogenicidade de diversas espécies de fungos entomopatogênicos a ninfas de 2o a 4o ínstares do psilídeo Diaphorina citri. Foram feitos bioensaios com Beauveria bassiana, Metarhizium anisopliae, Lecanicillium muscarum, L. longisporum, Paecilomyces fumosoroseus, P. farinosus, Syngliocladium sp. na concentração de 5 x 107 conídios/mL para cada patógeno, com exceção de Hirsutella thompsonii que foi aplicado na concentração de 2,8 x 107 conídios/mL. Utilizaram-se mudas de murta, Murraya paniculata, infestadas com as ninfas do inseto que foram pulverizadas com as suspensões conidiais dos patógenos. Os fungos B. bassiana, M. anisopliae, H. thompsonii, L. muscarum e P. fumosoroseus foram patogênicos para as ninfas do psilídeo. O isolado Esalq-PL63, de B. bassiana, causou mortalidade de aproximadamente 72% das ninfas, sete dias após a inoculação. Constatou-se que B. bassiananão conseguiu completar o desenvolvimento no corpo do hospedeiro, uma vez que a fase de conidiogênese não ocorreu. Mesmo assim, o isolado Esalq-PL63 pode ser considerado um promissor agente de controle microbiano de ninfas de D. citri por causar altos índices de mortalidade.

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