Lauren & Puneet
1. Determine sequence homology
2. Myb transcription factor expression in various fruits (containing anthocynanins)
3. Repeats in the blueberry genome (WGDs?)
4. The different expression patterns: in the fruit vs root; different times of the day; different seasons; various environmental factors
5. What phenolic compounds are regulated by myb
6. What is the BAHD family of phenolic ATs (mentioned in proposal) and what are the exceptions
7. ATP synthesis and glucose metabolism in blueberries.
8. The amount of t-RNA genes expressed in the blueberry
9. The number of introns, exons, transposable elements? What’s conserved?
Acid invertase
Invertase (EC 3.2.1.26 ) (systematic name: beta-fructofuranosidase) is an enzyme that catalyzes the hydrolysis (breakdown) of sucrose (table sugar). The resulting mixture of fructose and glucose is called inverted sugar syrup. Related to invertases are sucrases. Invertases and sucrases hydrolyze sucrose to give the same mixture of glucose and fructose. Invertases cleave the O-C(fructose) bond, whereas the sucrases cleave the O-C(glucose) bond.[1]
AI appears to be the key enzyme induced by root restriction that explains the higher sugar content found in grape berry produced under root restriction.
The characteristic rapid rise in the rate of sugar accumulation by the berries about halfway through development was preceded by an increase in the activity of invertase.
In fact, the protein fraction retrieved from a buffered medium after incubation of ripening berry slices contained a soluble invertase of presumably vacuolar origin with an acid pH-activity profile and a pI of about 4. [2]
These observations have led to speculations that suc hydrolysis primarily by acid invertase may determine the rate and extent of SUC storage in tomato fruit (Walker et al., 1978). In contrast, low levels of acid invertase are associated with high levels of SUC accumulation in L. hirsutum (Miron
The levels of invertase activity were found to vary significantly among 14 varieties of grapes tested. The crude invertases were, however, similar in both pH and temperature optima, as well as pH and thermal stabilities. The enzymes showed a high degree of thermostability and were also stable at acidic pH and high concentration of alcohol. A significant level of invertase activity persisted in several white table wines. The optimum activity of the enzyme purified from Semillon grape was observed at about 75°C and it was stable up to 70°C. Although the enzyme was stable between the pH 2 and 8, the optimum pH for its activity was about 4. The enzyme, whose molecular weight was estimated to be 65,000 by SDS polyacrylamide slab gel electrophoresis, was found to be a glycoprotein with a total carbohydrate content of 33%. This enzyme showed activity toward sucrose and raffinose, but was inactive on the other disaccharides tested. [3]
