Plasticity of petioles of white clover (Trifolium repens) to blue light

• Published in: Physiologia plantarum Vol. 112; no. 2; pp. 293 - 300
• Main Authors: Gautier, H. (INRA, Villeneuve d'Asq (France)), Varlet-Grancher, C, Membre, J.M
• Format: Journal Article
• Language: English
• Published: Copenhagen Munksgaard International Publishers 01.06.2001; Blackwell
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Economic plant physiology; ETAPAS DE DESARROLLO DE LA PLANTA; Fundamental and applied biological sciences. Psychology; Growth and development; LIGHT; LUMIERE; LUZ; Morphogenesis, differentiation, rhizogenesis, tuberization. Senescence; PECIOLO; PETIOLE; PETIOLES; PLANT DEVELOPMENTAL STAGES; Plant growth. Development of the storage organs; Plant physiology and development; STADE DE DEVELOPPEMENT VEGETAL; TRIFOLIUM REPENS; Vegetative apparatus, growth and morphogenesis. Senescence; Positioning; Growth; Environmental factor; Plant leaf; Photomorphogenesis; Morphogenesis; Leguminosae; Internode; Dicotyledones; Angiospermae; Orthotropy; Development; Plagiotropy; Spermatophyta; Fodder crop; Blue light; Elongation; Trifolium repens; Petiole
• ISSN: 0031-9317; 1399-3054
• DOI: 10.1034/j.1399-3054.2001.1120219.x

Petiole response of white clover to variations in blue light (BL) was studied on the main axis and on primary and secondary branches. The objectives of the present work were to determine (1) the time course of petiole response to BL and (2) whether these responses were dependent on petiole location. Under BL, clover had shorter petioles, and the switch to conditions without BL increased the length of forthcoming petioles. The fitting of a logistic function was used to compare the effect of BL on final petiole length, maximum elongation rate and the duration of petiole elongation between axes and phytomers. Petiole response to BL was not dependent on its location within the plant (axis type or phytomer position along the axis). A reduction in BL induced a rapid increase in leaf elongation rate, despite a small decrease in the duration of petiole elongation. Moreover, petiole response was dependent on petiole stage of development: the increase in the maximum rate of petiole elongation was inversely proportional to the petiole stage of development at the time of the switch. We conclude that the effects of BL on petiole elongation were not dependent on its position within the plant, whereas internode elongation resulted from the integration of light environment at the plant level. The difference between the responses of orthotropic and plagiotropic organs of clover to BL is discussed in relation to their structural function and localisation in the canopy.