Defence responses in leaves of resistant and susceptible pepper (Capsicum annuum L.) cultivars infected with different inoculum concentrations of Phytophthora capsici Leon
Küçük Resim Yok
Tarih
2011
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
ELSEVIER SCIENCE BV
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Three pepper cultivars (PM-702: resistant, Demre-8 and KM-hot: susceptible) with different resistances to Phytophthora capsici-22 (P. capsici-22) were inoculated with different concentrations of zoospores to analyze the time course of phenylalanine ammonia lyase (PAL) activity, malondialdehyde (MDA), hydrogen peroxide (H(2)O(2)), praline and total protein. Samples were collected from the leaves of three pepper cultivars on the 2nd, 4th. and 6th days after infection; important differences were observed in PAL activity, MDA amount, H(2)O(2), proline, and total protein with respect to zoospore concentration, infection time, and type of pepper cultivars. Activity of phenylalanine ammonia-lyase (PAL), the first enzyme in the phenylpropanoid biosynthetic pathway, was increased in inoculated leaves of all three cultivars. The increase in production of PAL upon challenge was higher in the infected plants compared to the non-infected (control) plants. An early induction of PAL was observed in the leaves of all peppers infected with P. capsici within two days, making it one of the detected earlier responses to infection. Moreover, pathogen stress increased the rate of lipid peroxidation (which is indicated by increasing MDA content). Production of reactive oxygen species, H(2)O(2), and lipid peroxidation increased in pepper leaves by increasing time of infection and inoculum concentration. The findings suggested that PM-702 pepper cultivar was inherently better protected against lipid peroxidation under P. capsici stress than KM-hot and Demre-8. In addition, it was observed that proline content in the leaves of infected susceptible cultivars increased with time, but highest proline and total protein in non-infected (control) leaves were recorded in resistant cultivar. (C) 2011 Elsevier B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
PAL, Lipid peroxidation, H(2)O(2), Proline, Total protein
Kaynak
SCIENTIA HORTICULTURAE
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
128
Sayı
4
