Reexamination of Chlorophyllase Function Implies Its Involvement in Defense against Chewing Herbivores
| Autor: | Satoru Makita, Masanori Ochiai, Tohru Tsuchiya, Shigeaki F. Hasegawa, Silvia Schelbert, Ayumi Tanaka, Shinsuke Sano, Stefan Hörtensteiner, Xueyun Hu, Ryouichi Tanaka |
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| Přispěvatelé: | University of Zurich, Tanaka, Ryouichi |
| Rok vydání: | 2015 |
| Předmět: |
Chlorophyllase
Physiology Endoplasmic reticulum fungi 1314 Physiology Plant Science Vacuole 580 Plants (Botany) Biology Plant cell biology.organism_classification Chloroplast chemistry.chemical_compound 10126 Department of Plant and Microbial Biology 1311 Genetics Biochemistry chemistry Chlorophyll Arabidopsis 1110 Plant Science Genetics Arabidopsis thaliana 10211 Zurich-Basel Plant Science Center |
| Zdroj: | Plant Physiology. 167:660-670 |
| ISSN: | 1532-2548 0032-0889 |
| DOI: | 10.1104/pp.114.252023 |
| Popis: | Chlorophyllase (CLH) is a common plant enzyme that catalyzes the hydrolysis of chlorophyll to form chlorophyllide, a more hydrophilic derivative. For more than a century, the biological role of CLH has been controversial, although this enzyme has been often considered to catalyze chlorophyll catabolism during stress-induced chlorophyll breakdown. In this study, we found that the absence of CLH does not affect chlorophyll breakdown in intact leaf tissue in the absence or the presence of methyl-jasmonate, which is known to enhance stress-induced chlorophyll breakdown. Fractionation of cellular membranes shows that Arabidopsis (Arabidopsis thaliana) CLH is located in the endoplasmic reticulum and the tonoplast of intact plant cells. These results indicate that CLH is not involved in endogenous chlorophyll catabolism. Instead, we found that CLH promotes chlorophyllide formation upon disruption of leaf cells, or when it is artificially mistargeted to the chloroplast. These results indicate that CLH is responsible for chlorophyllide formation after the collapse of cells, which led us to hypothesize that chlorophyllide formation might be a process of defense against chewing herbivores. We found that Arabidopsis leaves with genetically enhanced CLH activity exhibit toxicity when fed to Spodoptera litura larvae, an insect herbivore. In addition, purified chlorophyllide partially suppresses the growth of the larvae. Taken together, these results support the presence of a unique binary defense system against insect herbivores involving chlorophyll and CLH. Potential mechanisms of chlorophyllide action for defense are discussed. |
| Databáze: | OpenAIRE |
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