Isolation and characterisation of a family of laccases in maize
Isolation and characterisation of a family of laccases in maize
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DOI：
10.1016/j.plantsci.2006.03.007
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发表时间：
2006-08-01
期刊：
影响因子：
5.2
通讯作者：
Rigau, Joan
中科院分区：
文献类型：
--
作者：
Caparros-Ruiz, David;Fornale, Silvia;Rigau, Joan
植物漆酶是一种参与木质素生物合成最后一步的酶。聚合事件仍然很不清楚，涉及到其他酶，如过氧化物酶。为了更深入地了解这种聚合过程是如何在玉米中发生的，我们通过对玉米伸长根cDNA文库的差异筛选，分离出了编码一个漆酶家族的四个cDNA克隆。其中3个(ZmLa2、ZmLac4、ZmLac5)为碱性酶，1个(ZmLac3)为酸性酶。Southern分析表明，漆酶在玉米中属于多基因家族。系统发生树分析表明，ZmLac2、ZmLac4为ZmLac2、ZmLac4。和ZmLac5是紧密相关的酶，而ZmLac3是略有不同的酶。ZmLac2、ZmLac3的mRNA积累模式。ZmLac4和ZmLac5基因与玉米木质化区域相关。此外，ZmLac3受伤害诱导，而ZmLac2和ZmLac5受到抑制，ZmLac4基因的表达不受影响。综上所述，我们的结果表明，酸性ZmLac3酶可能参与了玉米酚类化合物的聚合。相反，与漆酶是参与广泛生理过程的酶的想法一致，用ZmLac2、ZmLac4和ZmLac5获得的结果导致我们排除了这些漆酶在木质素聚合中的直接作用。(C)2006爱思唯尔爱尔兰有限公司。保留所有权利。
Plant laccases are enzymes that have been proposed to participate in the last step of lignin biosynthesis. The Polymerisation event remains still much unknown, implicating other enzymes such as peroxidases. To gain more insight in how this polymerisation process takes place in maize, we isolated by differential screening of an elongation maize root cDNA library four cDNA clones encoding a family of laccases. Three of them (ZmLac2, ZmLac4, ZmLac5) were basic enzymes, while one of them (ZmLac3) was an acidic enzyme. Southern analysis indicates that laccases belong to a multigene family in maize. Phylogenetic analysis reveals that ZmLac2, ZmLac4. and ZmLac5 are closely related enzymes, whereas ZmLac3 is a slightly different enzyme. The pattern of mRNA accumulation of ZmLac2, ZmLac3. ZmLac4, and ZmLac5 genes correlates with the maize regions undergoing lignification. Moreover, ZmLac3 is induced by wounding, whereas ZmLac2 and ZmLac5 are repressed and ZmLac4 gene expression is not affected.Taken together, our results suggest that the acidic ZmLac3 enzyme could be involved in the polymerisation of phenolic compounds in maize. Instead, and in agreement with the idea that laccases are enzymes involved in a wide range of physiological processes, results obtained with ZmLac2, ZmLac4, and ZmLac5 lead us to exclude a direct role of these laccases in lignin polymerisation. (c) 2006 Elsevier Ireland Ltd. All rights reserved.