PLANT PHYSIOLOGY , Vol 107, Issue 2 621-630, Copyright © 1995 by American Society of Plant Biologists
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WHOLE PLANT, ENVIRONMENTAL, AND STRESS PHYSIOLOGY |
Near-Isogenic Lines of Maize Differing for Glycinebetaine
W. J. Yang, A. Nadolska-Orczyk, K. V. Wood, D. T. Hahn, P. J. Rich, A. J. Wood, H. Saneoka, G. S. Premachandra, C. C. Bonham, J. C. Rhodes, R. J. Joly, Y. Samaras, P. B. Goldsbrough and D. Rhodes
Department of Horticulture (W.-J.Y., D.T.H., P.J.R., A.J.W., G.S.P., R.J.J., Y.S., P.B.G., D.R.), Department of Chemistry (K.V.W.), and Department of Biochemistry (C.C.B., J.C.R.), Purdue University, West Lafayette, Indiana 47907
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[prime]-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.
