ISOLATION OF AN ARABIDOPSIS-THALIANA MUTANT, MTO1, THAT OVERACCUMULATES SOLUBLE METHIONINE - TEMPORAL AND SPATIAL PATTERNS OF SOLUBLE METHIONINE ACCUMULATION
ISOLATION OF AN ARABIDOPSIS-THALIANA MUTANT, MTO1, THAT OVERACCUMULATES SOLUBLE METHIONINE - TEMPORAL AND SPATIAL PATTERNS OF SOLUBLE METHIONINE ACCUMULATION
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DOI：
10.1104/pp.104.3.881
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发表时间：
1994-03-01
期刊：
影响因子：
7.4
通讯作者：
NAITO, S
中科院分区：
文献类型：
--
作者：
INABA, K;FUJIWARA, T;NAITO, S
我们分离出对蛋氨酸（Met）的毒性类似物——乙硫氨酸具有抗性的拟南芥突变体。其中一个突变体在营养生长期的地上部分可溶性Met积累量是野生型的10 ~ 40倍。突变体植株开花后，莲座区可溶性Met含量降至野生型水平，而花序先端区和未成熟果实的可溶性Met含量则是野生型的5 ~ 8倍。这些结果表明，可溶性Met的浓度受到时间和空间的调节，表明可溶性Met在生殖生长开始后被转运到下沉器官。这种致病突变被命名为mto1，是一种单核半显性突变，位于3号染色体上。可溶性氨基酸的积累谱表明，突变影响了Met生物合成途径的后期步骤。突变体的乙烯产量仅比野生型植物高40%，表明乙烯产量在Met合成后的一个步骤受到严格调控。该突变体将有助于研究氨基酸的易位，以及蛋氨酸生物合成和其他与蛋氨酸相关的代谢途径的调节。
We isolated Arabidopsis thaliana mutants that are resistant to ethionine, a toxic analog of methionine (Met). One of the mutants was analyzed further, and it accumulated 10- to 40-fold more soluble Met than the wild type in the aerial parts during the vegetative growth period. When the mutant plants started to flower, however, the soluble Met content in the rosette region decreased to the wild-type level, whereas that in the inflorescence apex region and in immature fruits was 5- to 8-fold higher than the wild type. These results indicate that the concentration of soluble Met is temporally and spatially regulated and suggest that soluble Met is translocated to sink organs after the onset of reproductive growth. The causal mutation, designated mto1, was a single, nuclear, semidominant mutation and mapped to chromosome 3. Accumulation profiles of soluble amino acids suggested that the mutation affects a later step(s) in the Met biosynthesis pathway. Ethylene production of the mutants was only 40% higher than the wild-type plants, indicating that ethylene production is tightly regulated at a step after Met synthesis. This mutant will be useful in studying the translocation of amino acids, as well as regulation of Met biosynthesis and other metabolic pathways related to Met.