Yang W J, Nadolska-Orczyk A, Wood K V, Hahn D T, Rich P J, Wood A J, Saneoka H, Premachandra G S, Bonham C C, Rhodes J C
Department of Horticulture, Purdue University, West Lafayette, Indiana 47907.
Plant Physiol. 1995 Feb;107(2):621-30. doi: 10.1104/pp.107.2.621.
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.
培育出了一系列近等基因的含甘氨酸甜菜碱和缺乏甘氨酸甜菜碱的玉米（Zea mays L.）F8品系对。这些品系对在单个位点的等位基因上存在差异；赋予甘氨酸甜菜碱积累的野生型等位基因被命名为Bet1，突变（隐性）等位基因被命名为bet1。利用一种测定甘氨酸甜菜碱和胆碱的新方法：稳定同位素稀释等离子体解吸质谱法，使用这些近等基因系来研究甘氨酸甜菜碱缺乏是否会影响甘氨酸甜菜碱前体胆碱的库大小。玉米中甘氨酸甜菜碱缺乏与游离胆碱库的显著扩大有关，但胆碱库大小的差异并不等于甘氨酸甜菜碱库大小的差异，这表明胆碱必须下调其自身的合成。与此一致的是，甘氨酸甜菜碱缺乏还与胆碱前体丝氨酸的积累有关。鉴定出了一个能检测bet1等位基因的随机扩增多态性DNA标记。在测试的62个F8家系中，只有当来自Bet1/bet1或bet1/bet1品系的DNA用作模板时，10聚体引物5'-GTCCTCGTAG才能产生1.2 kb的聚合酶链反应产物。测试的所有26个纯合Bet1/Bet1 F8家系对该标记均无反应。
