Inoculation and nitrate alter phytohormone levels in soybean roots:: differences between a supernodulating mutant and the wild type
Inoculation and nitrate alter phytohormone levels in soybean roots:: differences between a supernodulating mutant and the wild type
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DOI：
10.1007/s004250000265
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发表时间：
2000-06-01
期刊：
影响因子：
4.3
通讯作者：
Ligero, F
中科院分区：
文献类型：
--
作者：
Caba, JM;Centeno, ML;Ligero, F
不同细胞分裂素的水平。吲哚乙酸（IAA）和脱落酸（阿坝）在大豆（Glycine max [L.] Merr. CV.首次比较了Bragg及其超调节突变体nts 382。接种慢生根瘤菌48小时后，发现布拉格品种和突变体NTS 382之间的根的内源激素状态的定量和定性差异。六个量化的细胞分裂素，在每个基因型中排名相似，存在于较高的浓度（30-196%，平均异戊烯基腺苷和二氢玉米素核苷，分别）在突变体根。与此相反，阿坝含量是布拉格的2倍高，而IAA的基础水平[0.53 μ mol（g DW）（-1），平均]在两种基因型相似。在1 mM NO3-喂养布拉格根接种后48小时，IAA，阿坝和细胞分裂素异戊烯基腺嘌呤，异戊烯基腺苷定量增加相对于未接种的对照。然而，只有两个细胞分裂素增加的突变体。高NO3-（8毫米）显着降低根生长素浓度，既没有基因型差异，也没有接种诱导的生长素浓度增加布拉格观察在这些条件下。细胞分裂素和脱落酸（阿坝）则受8 mMNO 3-的影响较小。根IAA/细胞分裂素和阿坝/细胞分裂素的比例总是较高的布拉格相对于突变体，接种（主要是在布拉格）和硝酸盐（两种基因型）。这些结果与生长素爆发控制假说相一致。然而，关于NO3-的抑制作用，他们仍然没有定论。
The levels of different cytokinins. indole-3-acetic acid (IAA) and abscisic acid (ABA) in roots of Glycine max [L.] Merr. cv. Bragg and its supermodulating mutant nts382 were compared for the first time. Forty-eight hours after inoculation with Bradyrhizobium, quantitative and qualitative differences were found in the root's endogenous hormone status between cultivar Bragg and the mutant nts382. The six quantified cytokinins, ranking similarly in each genotype, were present at higher concentrations (30-196% on average for isopentenyl adenosine and dihydrozeatin riboside, respectively) in mutant roots. By contrast, the ABA content was 2-fold higher in Bragg, while the basal levels of IAA [0.53 mu mol (g DW)(-1), on average] were similar in both genotypes. In 1 mM NO3--fed Bragg roots 48 h post-inoculation, IAA, ABA and the cytokinins isopentenyl adenine, and isopentenyl adenosine quantitatively increased with respect to uninoculated controls. However, only the two cytokinins increased in the mutant. High NO3- (8 mM) markedly reduced root auxin concentration, and neither genotypic differences nor the inoculation-induced increase in auxin concentration in Bragg was observed under these conditions. Cytokinins and ABA, on the other hand, Were little affected by 8 mM NO3-. Root IAA/cytokinin and ABA/cytokinin ratios were always higher in Bragg relative to the mutant, and responded to inoculation (mainly in Bragg) and nitrate (both genotypes). The overall results are consistent with the auxin-burst-control hypothesis for the explanation of autoregulation and supernodulation in soybean. However, they are still inconclusive with respect to the inhibitory effect of NO3-.