(/sup 14/C)sucrose uptake and labeling of starch in developing grains of normal segl barley

Journal Article · Sun Jan 01 00:00:00 EST 1984 · Plant Physiol.; (United States)

OSTI ID:6583592

Felker, F C; Peterson, D M; Nelson, O E

Previous work showed that the segl mutant of barley (Hordeum vulgare o Betzes) did not differ from normal Betzes in plant growth, photosynthesis, or fertility, but it produced only shrunken seeds regardless of pollen source. To determine whether defects in sucrose uptake or starch synthesis resulted in the shrunken condition, developing grains of Betzes and segl were cultured in (/sup 14/C)sucrose solutions after slicing transversely to expose the endosperm cavity and free space. In both young grains (before genotypes differed in dry weight) and older grains (17 days after anthesis, when segl grains were smaller than Betzes), sucrose uptake and starch synthesis were similar in both genotypes on a dry weight basis. To determine if sucrose was hydrolyzed during uptake, spikes of Betzes and segl were allowed to take up (fructose-U-/sup 14/C)sucrose 14 days after anthesis and the radioactivity of endosperm sugars was examined during 3 hours of incubation. Whereas less total radioactivity entered the endosperm and the endosperm cavity (free space) of segl, in both genotypes over 96% of the label of endosperm sugars was in sucrose, and there was no apparent initial or progressive randomization of label among hexose moieties of sucrose as compared to the free space sampled after 1 hour of incubation. The authors conclude that segl endosperms are capable of normal sucrose uptake and starch synthesis and that hydrolysis of sucrose is not required for uptake in either genotype. Evidence suggests abnormal development of grain tissue of maternal origin during growth of segl grains.

• Research Organization: Univ. of Wisconsin, Madison
• OSTI ID: 6583592
• Journal Information: Plant Physiol.; (United States), Vol. 74:1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
SACCHAROSE
UPTAKE
SEEDS
MALFORMATIONS
STARCH
BIOSYNTHESIS
BARLEY
CARBON 14 COMPOUNDS
CEREALS
LABELLING
MUTATIONS
PLANT GROWTH
SACCHARIFICATION
TRACER TECHNIQUES
CARBOHYDRATES
CHEMICAL REACTIONS
DECOMPOSITION
DISACCHARIDES
GRAMINEAE
GRASS
GROWTH
HYDROLYSIS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LYSIS
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
PATHOLOGICAL CHANGES
PLANTS
POLYSACCHARIDES
REAGENTS
SACCHARIDES
SOLVOLYSIS
SYNTHESIS
550501* - Metabolism- Tracer Techniques