The Subcellular Localization of Isoperoxidases in Capsicum annuum Leaves and their Different Expression in Vegetative and Flowered Plants

• Published in: Annals of botany Vol. 72; no. 5; pp. 415 - 421
• Main Authors: Bernal, Marı́a A., Pedreño, Marı́a A., Calderón, Antonio A., Muñoz, Romualdo, Barceló, A.Ros, De CÁceres, F.Merino
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01.11.1993; Oxford University Press; Academic Press
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Biology and morphogenesis of the reproductive apparatus. Photoperiodism, vernalisation; Capsicum; Capsicum, floral state, leaf peroxidases, subcellular localization, vegetative state; Cell walls; Enzymes; floral state; Fundamental and applied biological sciences. Psychology; Internodes; leaf peroxidases; Leaves; Mesophyll; Physiology; Plant physiology; Plant physiology and development; Plants; Protoplasts; subcellular localization; Vacuoles; Vegetative and sexual reproduction, floral biology, fructification; vegetative state; Capsicum, floral state, leaf peroxidases, subcellular localization, vegetative state; Purification; Enzyme; Isozyme; Cytology; Plant leaf; Gene expression; Morphogenesis; Floral biology; Induced flowering; Peroxidases; Enzymatic activity; Dicotyledones; Angiospermae; Development; Flavoring crop; Capsicum annuum; Electrophoresis; Flowering; Isolation; Spermatophyta; Peroxidase; Oxidoreductases; Solanaceae; Localization
• ISSN: 0305-7364; 1095-8290
• DOI: 10.1006/anbo.1993.1127

The subcellular localization of leaf peroxidases (EC 1.11.1.7) and their expression in vegetative and flowered plants has been studied in Capsicum annuum (var. annuum) in order to assess whether the expression of new peroxidase isoenzymes can characterize the floral state which determines the beginning of reproductive development. The results showed that floral development is accompanied by a significant increase in the level of soluble (non-sedimentable) leaf peroxidase, independently of leaf position along the internodes, and therefore independently of the leaf age. An analysis of the leaf peroxidase isoenzyme patterns along the internodes for vegetative and flowered plants shows that the increase in peroxidase activity is due to a general increase in the activity of all the pre-existing peroxidase isoenzymes, although isoenzyme B2 and, especially, isoenzyme A1 showed a distinctive and major increase in activity. These two isoenzymes are mainly ionically-bound to cell walls, probably in equilibrium with the same isoenzymes moving freely in the cell-wall free spaces. The differs from other peroxidase isoenzymes, such as isoperoxidase B6, which is mainly located in the covalently-bound cell-wall fraction and in mesophyll vacuoles. These results are discussed in the light of a possible role of cell wall peroxidases as markers of the floral state in Capsicum annuum morphogenesis.