Abstract
of Chupakhina’s G.N. monograph
“The ascorbic acid system of plants”
Characteristic of plants ascorbic acid system, including ascorbic, de-
hydroascorbic and diketogulonic acids and oxidizing and reducing ascor-
bate enzymes, was suggested in this monography. It contents the results of
research of polychromatic and monochromatic light effects on system’s
components, the discussion of the question about photoreceptor light-
dependent synthesis of ascorbic acid. The paths of ascorbic acid biosyn-
thesis, the compartmentation of this process and subcellular localization
of acids of ascorbic acid system have been examined. The dependence of
this acids biosynthesis from photosynthesis and respiration was investi-
gated. In this case the data of acids biosynthesis in seedlings with altered
pigment composition, in the experimentally obtained albino seedlings
were used and while inhibition of separate stages of respiration, while
stimulation of cycle Krebs by its intermediates. It was first time when
diketogulonic acid was investigated as a component of ascorbic acid sys-
tem. The monography suggested the method of obtaining albino seed-
lings, their phisiologo-biochemestry characteristics, recommendation for
their using as model for investigation of light-dependent processes, which
were not connected with photosynthesis.
It was made for physiologists, biochemists, post-graduates and stu-
dents.
CONTENTS
Introduction ........................................................................................... 3
List of abbreviation ................................................................................ 5
Chapter 1. Acids and enzymes of ascorbic acid system ........................... 6
Chapter 2. Physiological role of ascorbic acid in the life
of the autotrophical organisms ............................................................. 10
2.1 Participation of ascorbic acid in the energy processes
of plants .....................................................................
.............. 10
2.2. Influence of an ascorbate on the expression of genome, enzymes
activity, aqueous regime, growth and another processes .............. 13
2.3. Defense function of ascorbic acid ............................................... 16
Chapter 3. Biosynthesis of ascorbic acid and its derivatives ....................... 18
3.1. Substrates for ascorbic acid biosynthesis de novo ....................... 18
3.2. Chemistry of biosynthesis .......................................................... 26
3.3. Compartmentation of ascorbic, dehydroascorbic
and diketogulonic acids biosynthesis ........................................... 30
Chapter 4. Influence of polychromatic and monochromatic light
on the biosynthesis of acids of ascorbic acid system ................................... 38
4.1. The light-dependent synthesis of ascorbic acid
in the green and etiolated seedlings ............................................. 38
4.2. Biosynthesis of ascorbic acid by the seedlings with change
correlation of the green and yellow pigments .............................. 54
4.3. Investigation of the faculty of the albino seedlings
to accumulate ascorbic acid in the light .......................... 55
4.4. Subcellular localization of ascorbic acid and its oxidized forms
in connection with light .............................................................. 64
4.5. Possible photoreceptors of the light-dependent ascorbic
acid synthesis .............................................................................. 71
Chapter 5. The albino seedlings as model for investigation
of the light-dependent processes, not connected with photosynthesis ......... 75
Chapter 6. Biosynthesis of ascorbic, dehydroascorbic and diketogulonic
acids, while inhibition of respiration and its stages .................................... 79
Chapter 7. Photoregulation activity of enzymes oxidizing ascorbic acid ..... 85
Conclusion .............................................................................................. 101
List of literature ...................................................................................... 104