A Gibberellin-Deficient Brassica Mutant-rosette.
A Gibberellin-Deficient Brassica Mutant-rosette.
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DOI：
10.1104/pp.89.2.482
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发表时间：
1989-02
期刊：
影响因子：
7.4
通讯作者：
S. B. Rood;D. Pearce;P. Williams;R. P. Pharis
中科院分区：
文献类型：
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作者：
S. B. Rood;D. Pearce;P. Williams;R. P. Pharis
从油菜快速循环系中鉴定出一个抑制茎部生长发育的单基因突变体（rossette [ros/ros]）。与正常植株相比，突变体发芽缓慢，花发育延迟或不完全，叶、叶柄和节间生长减少。通过叶面喷施或直接在莲座茎尖施用GA(3)，可使其快速开花、抽苔（芽伸长），并产生活籽。莲座茎部内源总赤霉素样物质（tanginbozu ' dwarf rice assay）含量约为正常快速循环系赤霉素样物质的十分之一，后者几乎完全由一种非常非极性的赤霉素样物质组成，在温和的酸水解下产生赤霉素（GA）和赤霉素（GA）。在正常的快速循环B. rapa谱线中，存在非极性的推定GA(1)和GA(3)共轭物，但另外，游离GA(1)和GA(3)丰富，并通过气相色谱-质谱-选择离子监测鉴定。以[(2)H(2)]GA(1)为内标，采用GC-MS-SIM法定量法线和花环中游离GA(1)和GA(3)的含量。14日龄莲座苗和正常苗每株的GA含量分别为5.3和23.2 ng(1)。第21天，莲座植株的GA(1)和GA(3)含量分别为7.7和26.1纳克/株，而正常植株的GA(1)和GA(3)含量分别为31.1和251.5纳克/株。因此，普通植物的类GA物质GA(1)或GA(3)的含量比莲座植物高4到10倍。ros等位基因导致GA水平降低，产生延迟萌发和开花的莲座表型，并降低茎部生长响应，这可能表明内源GA(1)和GA(3)在芸苔属这些过程中的调控作用。
A single-gene mutant (rosette [ros/ros]) in which shoot growth and development are inhibited was identified from a rapid cycling line of Brassica rapa (syn campestris). Relative to normal plants, the mutant germinated slowly, had delayed or incomplete floral development, and reduced leaf, petiole, and internode growth. The exogenous application of GA(3) by foliar spray or directly to the shoot tip of rosette resulted in rapid flowering, bolting (shoot elongation), and viable seed production. Shoots of rosette contained endogenous levels of total gibberellin (GA)-like substances (;Tan-ginbozu' dwarf rice assay) of about one-tenth of that of the normal rapid-cycling line of B. rapa which consisted almost entirely of a very nonpolar, GA-like substance which yielded GA(1) and GA(3) upon mild acid hydrolysis. In a normal rapid-cycling B. rapa line, the nonpolar putative GA(1) and GA(3) conjugates were present, but additionally, free GA(1) and GA(3) were abundant and identified by gas chromatography-mass spectrometry-selected ion monitoring. The quantities of free GA(1) and GA(3) in the normal line and in rosette were quantified by GC-MS-SIM using [(2)H(2)]GA(1) as an internal standard. Fourteen-day-old rosette and normal seedlings contained 5.3 and 23.2 ng GA(1) per plant, respectively. At day 21 the rosette plants contained 7.7 and 26.1 nanograms per plant of GA(1) and GA(3), while normal plants contained 31.1 and 251.5 nanograms per plant, respectively. Thus, normal plants contained from four to ten times higher levels of total GA-like substances, GA(1), or GA(3), than rosette. The ros allele results in reduced GA level, yielding the rosette phenotype whose delayed germination and flowering, and reduced shoot growth responses indicate a probable role for endogenous GA(1) and GA(3) in the regulation of these processes in Brassica.