HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Sheue, C.-R. Articles by Ku, M. S. B. Search for Related Content PubMed Articles by Sheue, C.-R. Articles by Ku, M. S. B. Agricola Articles by Sheue, C.-R. Articles by Ku, M. S. B.

Bizonoplast, a unique chloroplast in the epidermal cells of microphylls in the shade plant Selaginella erythropus (Selaginellaceae)¹

Department of Biological Resources, National Chiayi University, 300 Syuefu Rd., Chiayi 600, Taiwan; School of Integrative Biology, University of Queensland, Queensland 4752, Australia; Centre for Plant and Food Science, University of Western Sydney, Hawkesbury Campus, Locked Bag 1797, South Penrith NSW 1797, Australia; Institute of Physical Biology, University of South Bohemia, Zamek 136, Nove Hrady, CZ 37333, Czech Republic; School of Physics, The University of Melbourne, Victoria 3010, Australia; Forest Research Institute Malaysia, 52109 Kepong, Selangor, Malaysia; Department of Biological Sciences, National Sun Yat-sen University, 70 Lien-hai Rd., Kaohsiung 804, Taiwan; Departamento de Botânica, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, 31270-901, Belo Horizonte, Minas Gerais, Brazil; Department of Life Sciences and Institute of Ecology and Evolutionary Biology, National Taiwan University, 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan; Kaohsiung District Agricultural Improvement Station, 2-6 Dehe Rd., Changihih, Pingtung 908, Taiwan; Major Instruments Co., 9 Fl., 69-3, Chung-Cheng E. Rd., Sec. 2, Tan-Shui 251, Taipei, Taiwan; Natural Sciences, National Institute of Education, 1 Nanyang Walk, Nanyang Technological University, 637616 Singapore; Institute of Agricultural Biotechnology, National Chiayi University, 300 Syuefu Rd., Chiayi 600, Taiwan

ABSTRACT

Study of the unique leaf anatomy and chloroplast structure in shade-adapted plants will aid our understanding of how plants use light efficiently in low light environments. Unusual chloroplasts in terms of size and thylakoid membrane stacking have been described previously in several deep-shade plants. In this study, a single giant cup-shaped chloroplast, termed a bizonoplast, was found in the abaxial epidermal cells of the dorsal microphylls and the adaxial epidermal cells of the ventral microphylls in the deep-shade spike moss Selaginella erythropus. Bizonoplasts are dimorphic in ultrastructure: the upper zone is occupied by numerous layers of 2–4 stacked thylakoid membranes while the lower zone contains both unstacked stromal thylakoids and thylakoid lamellae stacked in normal grana structure oriented in different directions. In contrast, other cell types in the microphylls contain chloroplasts with typical structure. This unique chloroplast has not been reported from any other species. The enlargement of epidermal cells into funnel-shaped, photosynthetic cells coupled with specific localization of a large bizonoplast in the lower part of the cells and differential modification in ultrastructure within the chloroplast may allow the plant to better adapt to low light. Further experiments are required to determine whether this shade-adapted organism derives any evolutionary or ecophysiological fitness from these unique chloroplasts.

Key Words: bizonoplast • chloroplast • iridescence • iridoplast • Selaginella • shade plant • structure • thylakoid stacking