ABSTRACT
Two stable transformed lines containing antisense LeETR1 [corrected] or LeETR2 [corrected] sequences and their hybridized line were investigated to determine the effect of LeETR1 [corrected] and LeETR2 [corrected] specificity in the ethylene receptor family in tomato (Lycopersicon esculentum Mill.) on ethylene signaling. The transgenic line ale1 containing antisense LeETR1 [corrected] displayed shorter length of seedling grown in the dark and adult plant in the light, severe epinastic petiole, and accelerated abscission of petiole explant and senescence of flower explant, compared with its wild type B1. The transgenic line ale2 containing antisense LeETR2 [corrected] also exhibited shorter hypocotyls and slightly accelerated abscission. The phenotypes of cross line dale of LeETR1 [corrected] and LeETR2 [corrected] were close to ale1 in many aspects. These results suggested that LeETR1 [corrected] probably plays a relatively important role in ethylene signaling of tomato growth and development.
Subject(s)
Ethylenes , Metabolism , Gene Silencing , Physiology , Solanum lycopersicum , Physiology , Plant Proteins , Genetics , Metabolism , Plants, Genetically Modified , Physiology , RNA, Antisense , Physiology , Receptors, Cell Surface , Genetics , MetabolismABSTRACT
The characteristics of fruit ripening and expression of ripening-related genes were investigated in epi, an ethylene overproduction mutant of tomato (Lycopersicon esculentum Mill.). The epi produces apparently more ethylene than its wild type VFN8 at every stage of vegetative and fruit growth and ripening; compared to VFN8, the epi fruit showed higher CO2 evolution, faster descending of chlorophyll, slightly quicker increase of carotenoid and lycopene, and faster reduction in pericarp firmness during maturation and ripening; and the mRNAs of three ripening-related genes including E8, pTOM5 and pTOM6 were at higher levels in epi. The ripening-related characteristics changing of the fruit are consistent with the increase of ethylene production and ripening-related genes expression. These results suggest that epi mutation possibly did not affect the ethylene perception and signaling during fruit ripening, and that the modified characteristics of fruit ripening possibly resulted from the ethylene overproduction and increased expression of ripening-related genes.