4-Coumarate:coenzyme A ligase and isoperoxidase expression in Zinnia mesophyll cells induced to differentiate into tracheary elements.
4-Coumarate:coenzyme A ligase and isoperoxidase expression in Zinnia mesophyll cells induced to differentiate into tracheary elements.
复制标题
4-香豆酸：诱导分化为气管元件的百日草叶肉细胞中辅酶 A 连接酶和异过氧化物酶的表达。
DOI：
10.1104/pp.88.3.679
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发表时间：
1988
期刊：
影响因子：
7.4
通讯作者：
Galston,AW
中科院分区：
文献类型：
--
作者：
Church,DL;Galston,AW
在含有足够生长素和细胞分裂素的诱导培养基中，分离出了百日菊叶肉细胞。Envy分化为具木质部次生壁加厚的管状分子。当细胞在生长素和/或细胞分裂素水平降低的对照培养基中培养时，不发生分化。两种酶参与木质素的合成，4-香豆酸：辅酶A连接酶和过氧化物酶的活动进行了检查。诱导特异性阳离子过氧化物酶，可视化低pH聚丙烯酰胺凝胶电泳，是可检测到的可溶性和壁馏分culturedZinniacells长之前，管元素明显分化，因此是分化的早期标志。抑制或延迟分化的化合物（如抗生长素、抗细胞分裂素和衣霉素）改变这种过氧化物酶同工酶的表达。4-香豆酸：辅酶A连接酶活性仅在细胞分化时显著增加。总之，这些结果表明，在分化Zinniacells木质化的发病可能是由4-香豆酸：辅酶A连接酶合成的方式的前体的可用性控制。这些前体然后通过诱导特异性过氧化物酶在细胞壁中聚合成木质素。
When cultured in inductive medium containing adequate auxin and cytokinin, isolated mesophyll cells ofZinnia elegansL. cv Envy differentiate into tracheary elements with lignified secondary wall thickenings. Differentiation does not occur when cells are cultured in control medium, which has reduced levels of auxin and/or cytokinin. The activities of two enzymes involved in lignin synthesis, 4-coumarate:coenzyme A ligase and peroxidase, were examined. An induction-specific cationic isoperoxidase, visualized by low pH polyacrylamide gel electrophoresis, is detectable in soluble and wall fractions of culturedZinniacells long before tracheary elements visibly differentiate and is thus an early marker of differentiation. Compounds (such as antiauxins, anticytokinins, and tunicamycin) that inhibit or delay differentiation alter the expression of this isoperoxidase. 4-Coumarate:coenzyme A ligase activity increases dramatically only as cells differentiate. Together, these results suggest that the onset of lignification in differentiatingZinniacells might be controlled by the availability of precursors synthesized by way of 4-coumarate:coenzyme A ligase. These precursors would then be polymerized into lignin in the cell wall by the induction-specific isoperoxidase.