Pollination increases gibberellin levels in developing ovaries of seeded varieties of citrus
Pollination increases gibberellin levels in developing ovaries of seeded varieties of citrus
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DOI：
10.1104/pp.114.2.557
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发表时间：
1997-06-01
期刊：
影响因子：
7.4
通讯作者：
PrimoMillo, E
中科院分区：
文献类型：
--
作者：
BenCheikh, W;PerezBotella, J;PrimoMillo, E
甜橙菠萝种子品种的生殖和营养组织中含有GA（53）、GA（17）、GA（19）、GA（20）、GA(1)、GA（29）和GA(8)，以及GA（97）、3-外延-GA(1)和几种未鉴定的GA。3-epi-GA(1)作为内源性物质的加入是基于先前加入的[H-2(2)]GA(1)的异构化率的测量。授粉增加了GA（19）、GA（20）、GA（29）和GA(8)在子房发育中的数量。GA(1)含量在花期从5.0 ~ 9.5 ng/g干重增加，花期后降低。成熟花粉中GA含量很低。去势降低GA水平，导致卵巢迅速100%脱落。这种效应被授粉或施用赤霉素部分抵消(3)。在授粉后的子房中，反复施用多效唑降低了GA的数量，增加了子房脱落，但持续下降的模式与去雄引起的突然脱落不同。上述结果表明，在柑橘中，授粉增加了GA水平，减少了子房脱落，而在未授粉的子房中，外源GA(3)的存在也抑制了脱落。也有证据表明，传粉和气体并不像通常认为的那样，通过细胞分裂的重新激活来抑制子房脱落。
Reproductive and vegetative tissues of the seeded Pineapple cultivars of sweet orange (Citrus sinensis L.) contained the following C-13 hydroxylated gibberellins (GAs): GA(53), GA(17), GA(19), GA(20), GA(1), GA(29), and GA(8), as well as GA(97), 3-epi-GA(1), and several uncharacterized GAs. The inclusion of 3-epi-GA(1) as an endogenous substance was based on measurements of the isomerization rates of previously added [H-2(2)]GA(1). Pollination enhanced amounts of GA(19), GA(20), GA(29), and GA(8) in developing ovaries. Levels of GA(1) increased from 5.0 to 9.5 ng/g dry weight during anthesis and were reduced thereafter. The amount of GA in mature pollen was very low. Emasculation reduced GA levels and caused a rapid 100% ovary abscission. This effect was partially counteracted by either pollination or application of GA(3). In pollinated ovaries, repeated paclobutrazol applications decreased the amount of GA and increased ovary abscission, although the pattern of continuous decline was different from the sudden abscission induced by emasculation. The above results indicate that, in citrus, pollination increases GA levels and reduces ovary abscission and that the presence of exogenous GA(3) in unpollinated ovaries also suppresses abscission. Evidence is also presented that pollination and GAs do not, as is generally assumed, suppress ovary abscission through the reactivation of cell division.