Iron Deficiency Decreases Suberization in Bean Roots through a Decrease in Suberin-Specific Peroxidase Activity.
Iron Deficiency Decreases Suberization in Bean Roots through a Decrease in Suberin-Specific Peroxidase Activity.
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缺铁通过降低木栓质特异性过氧化物酶活性来减少豆根的木栓化。
DOI：
10.1104/pp.78.1.115
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发表时间：
1985
期刊：
影响因子：
7.4
通讯作者：
H. Bienfait
中科院分区：
文献类型：
--
作者：
P. Sijmons;P. Kolattukudy;H. Bienfait
对缺铁和富铁菜豆幼根部分木栓质含量进行了研究。测定了cv Prélude。采用气相色谱-质谱联用技术分析了LiAID（4）解聚后木栓素富集组分中的脂肪族成分。在正常根中，主要的脂肪族成分是ω-羟基酸和二羧酸，其中饱和C（16）和单不饱和C（18）是占优势的同系物。缺铁豆根中所含的木栓质的脂肪族成分在控制根中发现只有11%，虽然成分的相对组成并没有显着影响缺铁。木栓质聚合物的芳香族成分，可以通过碱性硝基苯氧化豆根样品释放的分析表明，在缺铁的条件下，对羟基苯甲醛，香草醛，和丁香醛减少了95%。木栓质合成的抑制在豆根不是由于铁依赖性ω-羟化酶活性的降低，因为正常的ω-羟化可以证明，无论是在体外与微粒体制剂和原位标记的ω-羟基和二羧酸与[（14）C]乙酸。过氧化物酶同工酶的水平，这是专门与木栓化抑制缺铁的25%，发现在控制根。其它过氧化物酶同工酶均不受铁营养状况的影响。木栓质相关过氧化物酶的活性恢复后3至4天内的铁应用到生长培养基。结果表明，在豆根，缺铁引起抑制木栓化引起的过氧化物酶活性的水平降低，这是所需的聚合的芳香域的木栓素，而合成的脂肪族成分的木栓素聚合物的能力不受损害。
The suberin content of young root parts of iron-deficient and iron-sufficient Phaseolus vulgaris L. cv Prélude was determined. The aliphatic components that could be released from suberin-enriched fractions by LiAID(4) depolymerization were identified by gas chromatography-mass spectrometry. In the normal roots, the major aliphatic components were omega-hydroxy acids and dicarboxylic acids in which saturated C(16) and monounsaturated C(18) were the dominant homologues. Iron-deficient bean roots contained only 11% of the aliphatic components of suberin found in control roots although the relative composition of the constituents was not significantly affected by iron deficiency. Analysis of the aromatic components of the suberin polymer that could be released by alkaline nitrobenzene oxidation of bean root samples showed a 95% decrease in p-hydroxybenzaldehyde, vanillin, and syringaldehyde under iron-deficient conditions. The inhibition of suberin synthesis in bean roots was not due to a decrease in Fe-dependent omega-hydroxylase activity since normal omega-hydroxylation could be demonstrated, both in vitro with microsomal preparations and in situ by labeling of omega-hydroxy and dicarboxylic acids with [(14)C]acetate. The level of the isozyme of peroxidase that is specifically associated with suberization was suppressed by iron deficiency to 25% of that found in control roots. None of the other extracted isozymes of peroxidase was affected by the iron nutritional status. The activity of the suberin-associated peroxidase was restored within 3 to 4 days after application of iron to the growth medium. The results suggest that, in bean roots, iron deficiency causes inhibition of suberization by causing a decrease in the level of isoperoxidase activity which is required for polymerization of the aromatic domains of suberin, while the ability to synthesize the aliphatic components of the suberin polymer is not impaired.