Fruits from Ripening Impaired, Chlorophyll Degradation and Jasmonate Insensitive Tomato Mutants have Altered Tocopherol Content and Composition

JULIANA ALMEIDA; RAMÓN ASIS; VIRGINIA N MOLINERI; IVAN SESTARI; BRUNO S LIRA; FERNANDO CARRARI; LÁZARO E PEREIRA PERES; MAGDALENA ROSSI

PHYTOCHEMISTRY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2015 vol. 111 p. 72 - 83

0031-9422

Since isoprenoids are precursors in the chlorophyll, carotenoid and tocopherol pathways, the study of their metabolism is of fundamental importance in understanding the regulatory crosstalk that contributes to the nutritional quality of tomato fruits. By means of an integrated analysis of metabolite and gene expression profiles, we dissected isoprenoid metabolism in ripening-impaired (ripening inhibitor and non-ripening), senescence-related (lutescent1 and green flesh) and jasmonate insensitive (jasmonic acid insensitive 1-1) tomato mutants, all in the Micro-Tom genetic background. It was found that the more upstream the location of the mutated gene, the more extensive the effect on the transcriptional profiles of the isoprenoid-related genes. Although there was a distinct effect of the analyzed mutations on chlorophyll, carotenoid and tocopherol metabolism, a metabolic adjustment was apparent such the antioxidant capacity mostly remained constant. Transcriptional profiles from the fruits of ripening and senescence-related tomato mutants suggested that maintenance of the de novo phytyl diphosphate synthesis might, in later ripening stages, compensate for the lack of chlorophyll-derived phytol used in tocopherol production. Interestingly, an impairment in jasmonate perception led to higher total tocopherol levels in ripe fruits, accompanied by an increase in antioxidant capacity, highlighting the contribution of tocopherols to this nutritionally important trait.