Towards an Understanding of Starch Biosynthesis and Its Relationship to Protein Synthesis in Plant Storage Organs

The most important harvested organs of crop plants, such as seeds, tubers and fruits, are often described as assimilate sinks. They play little or no part in the fixation of carbon through the production of sugars through photosynthesis, or in the uptake of nitrogen and sulphur, but import these assimilated resources to support metabolism and to store them in the form of starch, oils and proteins. Wild plants store resources in seeds and tubers to later support an emergent young plant. Cultivated crops are effectively storing resources to provide us with food and many have been bred to accumulate much more than would be required otherwise. For example, approximately 80% of a cultivated potato plant's dry weight is contained in its tubers, ten times the proportion in the tubers of its wild relatives (Inoue & Tanaka 1978). Cultivation and breeding has brought about a shift in the partitioning of carbon and nitrogen assimilate between the organs of the plant.

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Field Collection Techniques for Total Nonstructural Carbohydrate Analysis of Plant Storage Organs

Transactions of the Kansas Academy of Science ◽

10.2307/3627730 ◽

1986 ◽

Vol 89 (1/2) ◽

pp. 40 ◽

Cited By ~ 4

Author(s):

Walter H. Fick ◽

Dale L. Nolte

Keyword(s):

Field Collection ◽

Carbohydrate Analysis ◽

Nonstructural Carbohydrate ◽

Storage Organs ◽

Plant Storage

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Biology and Biochemistry of Underground Plant Storage Organs

Functionality of Food Phytochemicals ◽

10.1007/978-1-4615-5919-1_5 ◽

1997 ◽

pp. 113-132 ◽

Cited By ~ 3

Author(s):

Hector E. Flores ◽

Tere Flores

Keyword(s):

Storage Organs ◽

Plant Storage

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Activation of Protein Synthesis in Aging Potato Tuber Slices

Zeitschrift für Naturforschung B ◽

10.1515/znb-1971-1023 ◽

1971 ◽

Vol 26 (10) ◽

pp. 1064-1067 ◽

Cited By ~ 11

Author(s):

Günter Kahl

Keyword(s):

Protein Synthesis ◽

Potato Tuber ◽

Actinomycin D ◽

Leucine Incorporation ◽

Amino Acid Incorporation ◽

Acid Incorporation ◽

Fresh Potato ◽

Polyuridylic Acid ◽

Storage Organs

Whereas ribosome preparations of freshly sliced potato disks do not show appreciable activity in an in-vitro amino acid incorporation system, aging of the tissue leads to a greatly enhanced incorporation activity which reaches its maximum 24 hours after slicing. If ribosomes from freshly excised disks are provided with polyuridylic acid, their activity in the incorporation of phenylalanine is increased about 8 fold.Moreover, an RNA-fraction can be dissociated by EDTA from ribosomes of aged potato tuber slices, which sediments at 15 —18S, has a base composition different from that of 16S — rRNA, 5S-and 4S —RNA, and is not present on ribosomes of fresh slices. Its appearance is inhibited by actinomycin D and therefore most probably dependent on transcription. This compound, purified from sucrose gradients, enhances in vitro leucine incorporation into peptide material by ribosomes of fresh potato slices.The possibility is discussed that this fraction-among other factors-is responsible for the enhanced protein synthesis after slicing plant storage organs, and is indicative of a general derepression phenomenon in these tissues.

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Chemical Regulation of Formation of Plant Storage Organs

Journal of Pesticide Science ◽

10.1584/jpestics.17.2_s85 ◽

1992 ◽

Vol 17 (2) ◽

pp. S85-S91

Author(s):

Teruhiko YOSHIHARA

Keyword(s):

Chemical Regulation ◽

Storage Organs ◽

Plant Storage

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Synthesis of rRNA, tRNA and Other RNA-species Concomitant with Polyribosome Formation in Aging Potato Tuber Slices

Zeitschrift für Naturforschung B ◽

10.1515/znb-1971-1022 ◽

1971 ◽

Vol 26 (10) ◽

pp. 1058-1064 ◽

Cited By ~ 28

Author(s):

Günter Kahl

Keyword(s):

16S Rrna ◽

Actinomycin D ◽

Potato Tubers ◽

5S Rna ◽

Storage Tissue ◽

Peptide Formation ◽

Storage Organs ◽

Thin Disks ◽

Plant Storage

One of the earliest consequences of slicing plant storage organs such as potato tubers into thin disks is the formation of polysomes, which in potato slices is complete after 9 hours and is dependent on transcription. Fresh disks do not incorporate 32P, 3H-uridine or 14C-leucine into their ribosomes, whereas ribosomes and polysomes of aged disks use these precursors effectively. This development can be completely blocked by actinomycin D. Among the different RNAs synthesized during aging is 28S- and 16S—rRNA, 5S—RNA, tRNA, and a component sedimenting around 15—18S with a base-composition different from 16S—rRNA, 5S- and 4S—RNA and which supports peptide formation in an in vitro incorporation system.It is suggested that this compound represents mRNA, which is not available immediately after slicing the tissue. These findings are consistent with the view of a derepression phenomenon in sliced storage tissue.

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