Assimilate unloading from maize (Zea mays L. ) pedicel tissues. II. Effects of chemical agents on sugar, amino acid, and /sup 14/C-assimilate unloading

Journal Article · Thu Oct 01 00:00:00 EDT 1987 · Plant Physiol.; (United States)

OSTI ID:5394015

Porter, G A; Knievel, D P; Shannon, J C

Sugar, amino acid, and /sup 14/C-assimilate release from attached maize (Zea mays L.) pedicels was studied following treatment with several chemical inhibitors. In the absence of these agents, sugar release was nearly linear over a 7-hour period. At least 13 amino acids were released with glutamine comprising over 30% of the total. Release was not affected by potassium concentration, 10-minute pretreatments with p-chloromercuribenzene sulfonic acid (PCMBS) or dithiothreitol, and low concentrations of CaCl/sub 2/. Three hours or more exposure to PCMBS, dinitrophenol, N-ethylmaleimide, or 2,4,6-trinitrobenzene sulfonic acid strongly inhibited /sup 14/C-assimilate, sugar, and amino acid release from the pedicel. These treatments also reduced /sup 14/C-assimilate movement into the kernel bases. It is, therefore, likely that reduced unloading, caused by these relatively long-term exposures to chemical inhibitors, was related to reduced translocation of assimilates into treated kernels. Whether this effect is due to disruption of kernel metabolism and sieve element function or reduced assimilate unloading and subsequent accumulation of unlabeled assimilates within the pedicel tissues cannot be determined at this time.

• Research Organization: Pennsylvania State Univ., University Park
• OSTI ID: 5394015
• Journal Information: Plant Physiol.; (United States), Vol. 85:2
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
METABOLISM
DINITROPHENOL
BIOLOGICAL EFFECTS
IMIDES
SACCHAROSE
SULFONIC ACIDS
CARBON 14 COMPOUNDS
INHIBITION
MAIZE
TRACER TECHNIQUES
AROMATICS
CARBOHYDRATES
CARBOXYLIC ACIDS
CEREALS
DISACCHARIDES
GRASS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
NITRO COMPOUNDS
OLIGOSACCHARIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHENOLS
PLANTS
SACCHARIDES
560300* - Chemicals Metabolism & Toxicology
550201 - Biochemistry- Tracer Techniques