Chlorophyll Catabolism Pathway in Fruits of Capsicum annuum (L.): Stay-Green versus Red Fruits
Chlorophyll Catabolism Pathway in Fruits of Capsicum annuum (L.): Stay-Green versus Red Fruits
- Journal of Agricultural and Food Chemistry, 54(11), p.4035-4040, 2006 .
The aim of the present study is to investigate the chlorophyll catabolism pathway of wild-type red and stay-green mutants of Capiscum annuum (L.)fruits. In the wild-type red lines chlorophyll catabolism is concomitant with the start of carotenogenesis, whereas in the stay-green mutant lines the chlorophylls coexist with that process, even in over-ripe fruit. During the first stages of ripening, the chlorophyll a/chlorophyll b ratio is similar for both genotypes, but as ripening proceeds, the ratio in the stay-green lines becomes very high as a result of a blocked degradation of chlorophyll a while chlorophyll b is degraded at a normal rate. The absence of dephytylated chlorophylls in the wild-type lines distinguishes these from the mutant lines, in which there is a sequential accumulation of chlorophyllide a and pheophorbide a. Allomerized chlorophylls 132-OH-chlorophyll a and b)have also been identified in the catabolic process of the mutant lines, but are absent from the wild type. Consequently, an alteration in pheophorbide a oxygenase (PaO)activity seems to be responsible for the stay-green genotype in the lines of pepper analyzed in this study.
CAPSICUM ANNUUM (L.)
CHLOROPHYLL CATABOLISM
CHLOROPHYLL CATABOLITES FRUITS
PEPPER
STAY GREEN
The aim of the present study is to investigate the chlorophyll catabolism pathway of wild-type red and stay-green mutants of Capiscum annuum (L.)fruits. In the wild-type red lines chlorophyll catabolism is concomitant with the start of carotenogenesis, whereas in the stay-green mutant lines the chlorophylls coexist with that process, even in over-ripe fruit. During the first stages of ripening, the chlorophyll a/chlorophyll b ratio is similar for both genotypes, but as ripening proceeds, the ratio in the stay-green lines becomes very high as a result of a blocked degradation of chlorophyll a while chlorophyll b is degraded at a normal rate. The absence of dephytylated chlorophylls in the wild-type lines distinguishes these from the mutant lines, in which there is a sequential accumulation of chlorophyllide a and pheophorbide a. Allomerized chlorophylls 132-OH-chlorophyll a and b)have also been identified in the catabolic process of the mutant lines, but are absent from the wild type. Consequently, an alteration in pheophorbide a oxygenase (PaO)activity seems to be responsible for the stay-green genotype in the lines of pepper analyzed in this study.
CAPSICUM ANNUUM (L.)
CHLOROPHYLL CATABOLISM
CHLOROPHYLL CATABOLITES FRUITS
PEPPER
STAY GREEN