Observation of cytoplasmic and vacuolar malate in maize root tips by sup 13 C-NMR spectroscopy. [Zea mays L]

Journal Article · Sun Jan 01 00:00:00 EST 1989 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.89.1.197· OSTI ID:6906659

Chang, K; Roberts, J K.M. ^[1]

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1. Univ. of California, Riverside (USA)

The accumulation of malate by maize (Zea mays L.) root tips perfused with KH{sup 13}CO{sub 3} was followed by {sup 13}C nuclear magnetic resonance spectroscopy. In vivo nuclear magnetic resonance spectra contained distinct signals from two pools of malate in maize root tips, one at a pH {approximately}5.3 (assigned to the vacuole) and one at a pH > 6.5 (assigned to the cytoplasm). The ratio of cytoplasmic to vacuolar malate was lower in 12 millimeter long root tips than in 2 millimeter root tips. The relatively broad width of the signals from C1- and C4-labeled vacuolar malate indicated heterogeneity in vacuolar pH. During the 3 hour KH{sup 13}CO{sub 3} treatment, {sup 13}C-malate accumulated first primarily in the cytoplasm, increasing to a fairly constant level of {approximately}6 millimolar by 1 hour. After a lag, vacuolar malate increased throughout the experiment.

• OSTI ID: 6906659
• Journal Information: Plant Physiology; (USA), Vol. 89:1; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
MAIZE
PHYSIOLOGY
MALIC ACID
BIOCHEMICAL REACTION KINETICS
CARBON 13
CYTOPLASM
IN VIVO
METABOLISM
NMR SPECTRA
ROOTS
SPECTROSCOPY
CARBON ISOTOPES
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CEREALS
EVEN-ODD NUCLEI
GRASS
HYDROXY ACIDS
ISOTOPES
KINETICS
LIGHT NUCLEI
LILIOPSIDA
MAGNOLIOPHYTA
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
PLANTS
REACTION KINETICS
SPECTRA
STABLE ISOTOPES
550200* - Biochemistry