中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | (+)-abscisyl alcohol | 56298-25-0 | C15H22O3 | 250.338 |
(+)-脱落酸 | Abscisic acid | 21293-29-8 | C15H20O4 | 264.321 |
—— | (+)-8(2Z,4E)-(2S,3S,8R)-8-(5-hydroxy-3-methyl-2,4-pentadienyl)-2,3,7,9,9-pentamethyl-1,4-dioxaspiro<4.5>dec-6-en-8-ol | 141245-65-0 | C19H30O4 | 322.445 |
中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | (+)-abscisyl alcohol | 56298-25-0 | C15H22O3 | 250.338 |
(+)-脱落酸 | Abscisic acid | 21293-29-8 | C15H20O4 | 264.321 |
The flacca tomato (Lycopersicon esculentum) mutant displays a wilty phenotype as a result of abscisic acid (ABA) deficiency. The Mo cofactor (MoCo)-containing aldehyde oxidases (AO; EC 1.2.3.1) are thought to play a role in the final oxidation step required for ABA biosynthesis. AO and related MoCo-containing enzymes xanthine dehydrogenase (XDH; EC 1.2.1.37) and nitrate reductase (EC 1.6.6.1) were examined in extracts of the flacca tomato genotype and of wild-type (WT) roots and shoots. The levels of MoCo were found to be similar in both genotypes. No significant XDH or AO (MoCo-containing hydroxylases) activities were detected inflacca leaves; however, the mutant exhibited considerable MoCo-containing hydroxylase activity in the roots, which contained notable amounts of ABA. Native western blots probed with an antibody to MoCo-containing hydroxylases revealed substantial, albeit reduced, levels of cross-reactive protein in the flaccamutant shoots and roots. The ABA xylem-loading rate was significantly lower than that in the WT, indicating that the flacca is also defective in ABA transport to the shoot. Significantly, in vitro sulfurylation with Na2S reactivated preexisting XDH and AO proteins in extracts from flacca, particularly from the shoots, and superinduced the basal-level activity in the WT extracts. The results indicate that in flacca,MoCo-sulfurylase activity is impaired in a tissue-dependent manner.
flacca番茄(Lycopersicon esculentum)突变体因缺乏脱落酸(ABA)而表现出萎缩表型。钼辅因子(MoCo)含有的醛氧化酶(AO; EC 1.2.3.1)被认为在ABA生物合成所需的最终氧化步骤中发挥作用。AO和相关的MoCo含有的酶黄嘌呤脱氢酶(XDH; EC 1.2.1.37)和硝酸还原酶(EC 1.6.6.1)在flacca番茄基因型和野生型(WT)根和茎的提取物中进行了检查。发现两种基因型中MoCo的水平相似。在flacca的叶片中没有检测到显著的XDH或AO(MoCo含有的羟化酶)活性; 然而,突变体的根部表现出相当数量的MoCo含有的羟化酶活性,其中含有显著的ABA。原生西方印迹用MoCo含有的羟化酶抗体探测显示出flacca突变体的茎和根中存在大量的交叉反应蛋白,尽管水平有所降低。ABA木质部装载速率显著低于WT,表明flacca在ABA运输到茎中也存在缺陷。值得注意的是,在体外用Na2S进行硫酸化可重新激活flacca提取物中预先存在的XDH和AO蛋白质,特别是来自茎的提取物,并超诱导WT提取物中的基础水平活性。结果表明,在flacca中,MoCo-硫酸化酶活性受到组织依赖性的损害。
Abscisic acid (ABA) is a plant hormone involved in seed development
and germination and in responses to various environmental stresses. The
last step of ABA biosynthesis involves oxidation of abscisic aldehyde,
and aldehyde oxidase (EC