Participation of cob tissue in the transport of medium components into maize kernels cultured in vitro

Conference · Tue May 01 00:00:00 EDT 1990 · Plant Physiology, Supplement; (USA)

OSTI ID:5851209

Felker, F C ^[1]

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1. USDA, Peoria, IL (USA)

Maize (Zea mays L.) kernels cultured in vitro while still attached to cob pieces have been used as a model system to study the physiology of kernel development. In this study, the role of the cob tissue in uptake of medium components into kernels was examined. Cob tissue was essential for in vitro kernel growth, and better growth occurred with larger cob/kernel ratios. A symplastically transported fluorescent dye readily permeated the endosperm when supplied in the medium, while an apoplastic dye did not. Slicing the cob tissue to disrupt vascular connections, but not apoplastic continuity, greatly reduced ({sup 14}C)sucrose uptake into kernels. ({sup 14}C)Sucrose uptake by cob and kernel tissue was reduced 31% and 68%, respectively, by 5 mM PCMBS. L-({sup 14}C)glucose was absorbed much more slowly than D-({sup 14}C)glucose. These and other results indicate that phloem loading of sugars occurs in the cob tissue. Passage of medium components through the symplast cob tissue may be a prerequisite for uptake into the kernel. Simple diffusion from the medium to the kernels is unlikely. Therefore, the ability of substances to be transported into cob tissue cells should be considered in formulating culture medium.

• OSTI ID: 5851209
• Report Number(s): CONF-9007196--
• Journal Information: Plant Physiology, Supplement; (USA), Journal Name: Plant Physiology, Supplement; (USA) Vol. 93:1; ISSN PPYSA; ISSN 0079-2241
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
CARBOHYDRATES
CARBON 14 COMPOUNDS
CEREALS
DISACCHARIDES
GLUCOSE
GRAMINEAE
HEXOSES
IN VITRO
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LILIOPSIDA
MAGNOLIOPHYTA
MAIZE
MONOSACCHARIDES
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
PLANTS
SACCHARIDES
SACCHAROSE
TRACER TECHNIQUES
UPTAKE