S-adenosylhomocysteine hydrolase (SAHH) functions as an enzyme catalyzing the reversible hydrolysis of S-adenosylhomocysteine to homocysteine and adenosine. In the present work we have investigated its role in the ripening process of tomato fruit. Among the three SlSAHH genes we demonstrated that SlSAHH2 was highly accumulated during fruit ripening and strongly responded to ethylene treatment. ...

Polygalacturonase [PG; poly(1,4-alpha-D-galacturonide) glycanhydrolase; EC 3.2.1.15] is expressed in tomato only during the ripening stage of fruit development. PG becomes abundant during ripening and has a major role in cell wall degradation and fruit softening. Tomato plants were transformed to produce antisense RNA from a gene construct containing the cauliflower mosaic virus 35S promoter an...

Ripening of fleshy fruits is a complex process that involves dramatic changes in color, texture, flavor, and aroma, which is essentially regulated by multiple hormone signals. Although the metabolic mechanisms for the regulation of fruit development and ripening have been studied extensively, little is known about the signaling mechanisms underlying this process. FERONIA has been increasingly s...

In plants, microRNAs (miRNAs) play essential roles in growth, development, yield, stress response and interactions with pathogens. However no miRNA has been experimentally documented to be functionally involved in fruit ripening although many miRNAs have been profiled in fruits. Here we show that SlymiR157 and SlymiR156 differentially modulate ripening and softening in tomato (Solanum lycopersi...

Expansins are plant proteins that have the capacity to induce extension in isolated cell walls and are thought to mediate pH-dependent cell expansion. J.K.C. Rose, H.H. Lee, and A.B. Bennett ([1997] Proc Natl Acad Sci USA 94: 5955-5960) reported the identification of an expansin gene (LeExp1) that is specifically expressed in ripening tomato (Lycopersicon esculentum) fruit where cell wall disas...

Abscisic acid (ABA) plays important roles during tomato fruit ripening. To study the regulation of carotenoid biosynthesis by ABA, the SlNCED1 gene encoding 9-cis-epoxycarotenoid dioxygenase (NCED), a key enzyme in the ABA biosynthesis, was suppressed in tomato plants by transformation with an RNA interference (RNAi) construct driven by a fruit-specific E8 promoter. ABA accumulation and SlNCED1...

MADS-domain proteins are important transcription factors involved in many biological processes of plants. In our study, a tomato MADS-box gene, SlFYFL, was isolated. SlFYFL is expressed in all tissues of tomato and significantly higher in mature leave, fruit of different stages, AZ (abscission zone) and sepal. Delayed leaf senescence and fruit ripening, increased storability and longer sepals w...

The activity of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) and the level of its mRNA have been determined at various stages of tomato fruit development. The HMGR reaction makes mevalonate, a necessary component in the synthesis of all isoprene containing compounds, such as sterols and carotenoids. A cDNA clone encoding the active site region of HMGR has been isolated from a tomato l...

Expansins are proteins that induce extension in isolated plant cell walls in vitro and have been proposed to disrupt noncovalent interactions between hemicellulose and cellulose microfibrils. Because the plant primary cell wall acts as a constraint to cell enlargement, this process may be integral to plant cell expansion, and studies of expansins have focused on their role in growth. We report ...

Glutamate (Glu) is a taste enhancer that contributes to the characteristic flavour of foods. In fruit of tomato (Solanum lycopersicum L.), the Glu content increases dramatically during the ripening process, becoming the most abundant free amino acid when the fruit become red. There is also a concomitant increase in NADH-dependent glutamate dehydrogenase (GDH) activity during the ripening transi...