Winemaker’s Bookshelf
Leading researchers share their findings, some of which are surprising.
T
his book contains a summary of recent advances in the knowledge of grape biochemistry. Wherever
possible, it has pointed out the unique pathways that occur only in grapes, but many biochemical mechanisms are shared with other organisms, including humans.
Physiology and Biotechnology. Second edition. Roubelakis- Angelakis, K.A. 2009. Editor. Grapevine Molecular Springer Science and Business Media. 636 pp. The chapters are reviews by top grape researchers. I found that many are written in a style that is easily followed, with figures to summarize data, straightforward introductions, and discussion of potential practical application of new knowledge. I found some chapters difficult to follow because the sentences were broken up by multiple citations and unfamiliar abbreviations. In these cases, I often had to work harder to find the point of the author’s arguments.
The book is divided into 21 chapters, with an average of 30 pages per chapter. There are contributions from 73 scientists.
The first edition was published in 2001, and because of the publication of the grapevine genome sequence in 2007, the first edition became quickly out of date. We have now moved onward a further eight years, but there has been no technical advance so disruptive as the mapping of the whole genome. Recent advances have been more incremental.
The book opens with a detailed discussion of the molecular aspects of grape bud dormancy release. I found this especially interesting because I recently viewed an equatorial vineyard in which most of the accepted conditions that lead to grapevine dormancy were violated. I could easily have devoted the rest of this review to a summary of this topic alone. The other chapters are also detailed summaries of the current
28 British Columbia FRUIT GROWER • Summer 2017
By Gary Strachan Grape knowledge at the molecular level
knowledge of various aspects of grapevine metabolism. The second chapter deals with sulphur metabolism. I didn’t
know that some plants utilize
sulphur as a phytoalexin (a substance produced by the plant to ward off infection). They can take in sulphate, reduce it to molecular sulphur and deposit it onto the plant surfaces to inhibit fungal and insect infestations.
There is much more in the chapter, but I was attracted to the quirkiness of the only mineral phytoalexin production known in plants.
The third chapter (and I won't summarize all 21 chapters) deals with vine water status and mineral composition. There is a good discussion of the ways in which minerals are taken up and partitioned within the plant and fruit. This leads, of course to the next chapter which deals with water transport. I was introduced to a new (to me) concept called aquaporins. These are proteins
that act like a molecular sieve or valve. They can limit water uptake and distribution during periods of drought.
We all know the importance of sugar synthesis in grapes, but we take the details of transport and sensing for granted. The system of
synthesis, storage, interconversion and control is far more complex than I was told in
undergraduate biochemistry lectures.
most
One of the important
enzymes in man is
alcohol dehydrogenase (ADH). This is the liver enzyme that detoxifies alcohol from the bloodstream and converts it to acetaldehyde that can be utilized in a wide range of metabolic reactions throughout the body. I had no idea of the importance of the importance of ADH to grapevines throughout all developmental stages.
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