Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5905729 | Gene | 2014 | 8 Pages |
Abstract
Chlorophyll is the most abundant pigment on earth and even though it is known that its high photo-excitability necessitates a tight regulation of its degradation pathway, to date there are still several steps in chlorophyll breakdown that remain obscure. In order to better understand the 'degreening' processes that accompany leaf senescence and fruit ripening, we characterized the enzyme-encoding genes involved in dephytylation from tomato (Solanum lycopersicum). A single pheophytinase (PPH) gene and four chlorophyllase (CLH) genes were identified in the tomato genome. A phenetic analysis revealed two groups of CLHs in eudicot species and further evolutionary analysis indicated that these enzymes are under diverse selection pressures. A comprehensive expression profile analysis also suggested functional specificity for these dephytylating enzymes. The integrated analysis allows us to propose three general roles for chlorophyll dephytylation: i) PPH, which is under high selective constraint, is responsible for chlorophyll degradation during developmentally programed physiological processes; ii) Group I CLHs, which are under relaxed selection constraint, respond to environmental and hormonal stimuli and play a role in plant adaptation plasticity; and iii) Group II CLHs, which are also under high selective constraint, are mostly involved in chlorophyll recycling.
Keywords
RCCred chlorophyll cataboliteprimary fluorescent chlorophyll catabolitepFCCMurashige and Skoog mediaChlideCLHPheophorbide a oxygenasePheophytinPheoPheophorbideSAG12LTRABAChlPAOSGRPPHLikelihood ratio testabscisic acidPhotosynthetically active radiationParstandard errorRipeningChlorophyllUntranslated regionsUTR یا untranslated regions SenescenceChlorophyllideChlorophyllaseTomato
Related Topics
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Biochemistry, Genetics and Molecular Biology
Genetics
Authors
Bruno Silvestre Lira, Nathalia de Setta, Daniele Rosado, Juliana Almeida, Luciano Freschi, Magdalena Rossi,