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Changes in stem lignins (monomer composition and crosslinking) and peroxidase are related with the maintenance of leaf photosynthetic integrity during Verticillium wilt in Capsicum annuum
Author(s) -
Pomar Federico,
Novo Marta,
Bernal María A.,
Merino Fuencisla,
Barceló A. Ros
Publication year - 2004
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2004.01092.x
Subject(s) - verticillium dahliae , verticillium wilt , photosynthesis , cultivar , biology , capsicum annuum , lignin , botany , peroxidase , pepper , horticulture , enzyme , biochemistry
Summary• Verticillium dahliae is a soilborne pathogen that causes vascular wilt in pepper ( Capsicum annuum var. annuum ). Here we study to what extent changes in the lignification response of peppers condition tolerance of wilt. • For this, the quantum yield (Φ PSII ), the linear e lectron t ransport r ate (ETR), and the lignification response (monomer composition and crosslinking) were studied in three C. annuum cultivars differing in degree of tolerance. • The results showed that in tolerant cultivars (Padrón and Yolo Wonder), both Φ PSII and ETR showed significantly higher levels at saturating photosynthetically active radiation values. This was not, however, the case for cv. Luesia, which showed a significant decrease in Φ PSII , ETR and nonphotochemical quenching values, suggesting that photochemical processes are strongly damaged in this cultivar as a consequence of the disease. The analysis of stem lignins in tolerant cultivars revealed that they were mainly composed of p ‐hydroxyphenyl units, while levels of β‐ O‐ 4‐linked coniferyl and sinapyl alcohols were significantly lower. • It is concluded that through the observed changes in stem lignins (monomer composition and crosslinking) peppers retard, since they maintain leaf photosynthetic integrity, but do not stop (since wilt symptoms are not avoided) V. dahliae fungal hyphae penetration.