Near-isogenic lines of maize differing for glycinebetaine.
A series of near-isogenic glycinebetaine-containing and -deficient F8 pairs of Zea mays L. (maize) lines were developed. The pairs of lines differ for alternative alleles of a single locus; the wild-type allele conferring glycinebetaine accumulation is designated Bet1 and the mutant (recessive) allele is designated bet1. The near-isogenic lines were used to investigate whether glycinebetaine deficiency affects the pool size of the glycinebetaine precursor, choline, using a new method for glycinebetaine and choline determination: stable isotope dilution plasma desorption mass spectrometry. Glycinebetaine deficiency in maize was associated with a significant expansion of the free choline pool, but the difference in choline pool size was not equal to the difference in glycinebetaine pool size, suggesting that choline must down-regulate its own synthesis. Consistent with this, glycinebetaine deficiency was also associated with the accumulation of the choline precursor, serine. A randomly amplified polymorphic DNA marker was identified that detects the bet1 allele. In 62 F8 families tested the 10-mer primer 5'-GTCCTCGTAG produced a 1.2-kb polymerase chain reaction product only when DNA from Bet1/bet1 or bet1/bet1 lines was used as template. All 26 homozygous Bet1/Bet1 F8 families tested were null for this marker.
Yang
W J
WJ
Department of Horticulture, Purdue University, West Lafayette, Indiana 47907.
Nadolska-Orczyk
A
A
Wood
K V
KV
Hahn
D T
DT
Rich
P J
PJ
Wood
A J
AJ
Saneoka
H
H
Premachandra
G S
GS
Bonham
C C
CC
Rhodes
J C
JC
D000483:Alleles; D001483:Base Sequence; D001622:Betaine / Q000378:metabolism*; D002794:Choline / Q000378:metabolism; D003433:Crosses, Genetic; D017931:DNA Primers; D018744:DNA, Plant / Q000302:isolation & purification; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism
D017931:DNA Primers; D018744:DNA, Plant; D001622:Betaine; D002794:Choline