Virus-induced gene silencing of pea CHLI and CHLD affects tetrapyrrole biosynthesis, chloroplast development and the primary metabolic network.
Plant Physiol Biochem
; 65: 17-26, 2013 Apr.
Article
en En
| MEDLINE
| ID: mdl-23416492
ABSTRACT
The first committed and highly regulated step of chlorophyll biosynthesis is the insertion of Mg(2+) into protoporphyrin IX, which is catalyzed by Mg chelatase that consists of CHLH, CHLD and CHLI subunits. In this study, CHLI and CHLD genes were suppressed by virus-induced gene silencing (VIGS-CHLI and VIGS-CHLD) in pea (Pisum sativum), respectively. VIGS-CHLI and VIGS-CHLD plants both showed yellow leaf phenotypes with the reduced Mg chelatase activity and the inactivated synthesis of 5-aminolevulinic acid. The lower chlorophyll accumulation correlated with undeveloped thylakoid membranes, altered chloroplast nucleoid structure, malformed antenna complexes and compromised photosynthesis capacity in the yellow leaf tissues of the VIGS-CHLI and VIGS-CHLD plants. Non-enzymatic antioxidant contents and the activities of antioxidant enzymes were altered in response to enhanced accumulation of reactive oxygen species (ROS) in the chlorophyll deficient leaves of VIGS-CHLI and VIGS-CHLD plants. Furthermore, the results of metabolite profiling indicate a tight correlation between primary metabolic pathways and Mg chelatase activity. We also found that CHLD induces a feedback-regulated change of the transcription of photosynthesis-associated nuclear genes. CHLD and CHLI silencing resulted in a rapid reduction of photosynthetic proteins. Taken together, Mg chelatase is not only a key regulator of tetrapyrrole biosynthesis but its activity also correlates with ROS homeostasis, primary interorganellar metabolism and retrograde signaling in plant cells.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas de Plantas
/
Virus
/
Cloroplastos
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Pisum sativum
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Silenciador del Gen
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Tetrapirroles
Idioma:
En
Revista:
Plant Physiol Biochem
Asunto de la revista:
BIOQUIMICA
/
BOTANICA
Año:
2013
Tipo del documento:
Article