biologia plantarum

Biologia plantarum 65:333-341, 2021 | DOI: 10.32615/bp.2021.048

Immunogold-labelling localization of chlorophyllase-2 at different developmental stages of Pachira macrocarpa leaves

T.C. LEE^{1, 4}, K.H. LIN², M.Y. HUANG^{3, *}, C.-M. YANG^{4, *}

¹ Anxi College of Tea Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China

² Department of Horticulture and Biotechnology, Chinese Culture University, Taipei 11114, Taiwan

³ Department of Life Sciences and Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung, 40227, Taiwan

⁴ Biodiversity Research Center, Academia Sinica, Taipei 11115, Taiwan

Chlorophyllases (Chlases) are housekeeping proteins in plant cells. The dephytylating enzymes can catalyze chlorophyll (Chl) to form chlorophyllide, but the distribution of Chlases in plant cells is still an interesting debate. Previously, we showed that PmCLH2 was a nuclear-encoded gene, and PmCLH2 protein was located in cytosol and chloroplasts of Pachira macrocarpa (Pm). In this study, the antibody of PmCLH2 was made and used by the immunogold-labelling technique to detect the localization of Chlase of Pm leaves at four developmental stages (young, mature, yellowing, and senescent). The transmission electron microscopy results show that Chlases were comprehensively found in parts of the chloroplast, such as the inner membrane of the envelope, grana, and the thylakoid membrane as well as in cytosol, and vacuoles at young, mature, and yellowing stages of Pm leaves, but not in the cell wall, plasma membrane, mitochondria, and nucleus. In short, PmCLH2 was mainly detected in vacuoles at the senescent stage, but a few were found in the chloroplasts. A pathway is proposed to explain the birth and death of Chl, Chlase, and chloroplasts in higher plants.

Keywords: chlorophyllase, chloroplast, immunogold-labelling, Pachira macrocarpa, senescence, transmission electron microscopy.

Received: May 23, 2021; Revised: July 16, 2021; Accepted: August 8, 2021; Published online: December 21, 2021  Show citation