TY - JOUR

T1 - The effects of patulin from Penicillium vulpinum on seedling growth, root tip ultrastructure and glutathione content of maize

AU - Ismaiel, Ahmed A.

AU - Papenbrock, Jutta

N1 - Funding information: Acknowledgments This work was financially supported by a research grant from the Deutsche Forschungsgemeinschaft (PA 764/14-1, AOBJ 587711). We thank Pamela von Trzebiatowski and Julia Volker for their excellent technical assistance.

PY - 2014/7

Y1 - 2014/7

N2 - A culture of Penicillium vulpinum CM1 isolated from a soil sample cultivated with maize was examined for the production of the mycotoxins cyclopiazonic acid, griseofulvin, patulin (PAT), and roquefortine C. The fungal strain was positive for PAT- and roquefortine C-producing ability, while it showed negative producing ability for cyclopiazonic acid, and griseofulvin. Both PAT and roquefortine C toxins were tested for their inhibitory effect on the germination of maize seeds. Roquefortine C showed no phytotoxicity up to a concentration of 100 μg ml-1. However, a notable reduction in the average values of fresh weight and length of roots and shoots was observed following application of PAT and a culture filtrate of P. vulpinum to maize seedlings. The phytotoxic effect was found to be dose-dependent. To analyse the cellular effects of PAT, maize root tips were treated with PAT at different concentrations. The higher dose of 25 μg ml-1 exhibited morphological changes in the nature of cytoplasm and cytoplasmic organelles as was shown by transmission electron microscopy. Furthermore, an increase in the vacuolation with localized tonoplast dissolution was observed. At this concentration, there was evidence of a disruption of lipid metabolism. On the metabolic level, the phytotoxicity of PAT and the culture filtrate of P. vulpinum led to alterations in the total reduced glutathione (GSH) concentration in maize seedlings. The GSH concentrations examined in roots and shoots after PAT, fungal filtrate or fungal crude extract treatments were enhanced compared with control treatments. Findings further showed higher total GSH levels in shoots than in roots following treatments either with PAT or the fungal crude extract. The results are discussed in the context of known herbicide and metal effects on GSH synthesis and transport mechanisms.

AB - A culture of Penicillium vulpinum CM1 isolated from a soil sample cultivated with maize was examined for the production of the mycotoxins cyclopiazonic acid, griseofulvin, patulin (PAT), and roquefortine C. The fungal strain was positive for PAT- and roquefortine C-producing ability, while it showed negative producing ability for cyclopiazonic acid, and griseofulvin. Both PAT and roquefortine C toxins were tested for their inhibitory effect on the germination of maize seeds. Roquefortine C showed no phytotoxicity up to a concentration of 100 μg ml-1. However, a notable reduction in the average values of fresh weight and length of roots and shoots was observed following application of PAT and a culture filtrate of P. vulpinum to maize seedlings. The phytotoxic effect was found to be dose-dependent. To analyse the cellular effects of PAT, maize root tips were treated with PAT at different concentrations. The higher dose of 25 μg ml-1 exhibited morphological changes in the nature of cytoplasm and cytoplasmic organelles as was shown by transmission electron microscopy. Furthermore, an increase in the vacuolation with localized tonoplast dissolution was observed. At this concentration, there was evidence of a disruption of lipid metabolism. On the metabolic level, the phytotoxicity of PAT and the culture filtrate of P. vulpinum led to alterations in the total reduced glutathione (GSH) concentration in maize seedlings. The GSH concentrations examined in roots and shoots after PAT, fungal filtrate or fungal crude extract treatments were enhanced compared with control treatments. Findings further showed higher total GSH levels in shoots than in roots following treatments either with PAT or the fungal crude extract. The results are discussed in the context of known herbicide and metal effects on GSH synthesis and transport mechanisms.

KW - Maize

KW - Patulin (PAT)

KW - Phytotoxicity

KW - Reduced glutathione (GSH)

KW - Root

KW - Shoot

KW - Subcellular Structures

UR - http://www.scopus.com/inward/record.url?scp=84901980164&partnerID=8YFLogxK

U2 - 10.1007/s10658-014-0406-9

DO - 10.1007/s10658-014-0406-9

M3 - Article

AN - SCOPUS:84901980164

VL - 139

SP - 497

EP - 509

JO - European Journal of Plant Pathology

JF - European Journal of Plant Pathology

SN - 0929-1873

IS - 3

ER -