摘要
在大多数维管植物中4CL以基因家族形式出现。4CL基因成员在植物组织中差异表达,参与不同的苯丙烷类衍生物的生物合成。4CL基因的表达受发育调控,其表达还能被环境因子激活,如各种伤害、病原菌侵染、紫外线辐射等。4CL具有高度趋异的底物偏好性及底物特异性,决定4CL同工酶底物特异性的因素可能是结合沟的空间限制而不是底物和多肽链之间的特异性相互作用。在4CL氨基酸序列中存在2个保守的肽基序(motif),肽基序BoxⅠ,SSGTTGLPKGV,肽基序BoxⅡ,GEICIRG。应用反义技术已经成功地将4CL基因用于调控模式植物拟南芥、烟草及木本植物美洲山杨、毛白杨木质素的生物合成。未来的研究应侧重以下方向:应用多种技术分离、鉴定出更多木本植物的4CL基因;通过生物技术来增加木本植物木质素含量的研究也值得期待;建立4CL蛋白结晶体系,从原子水平解析4CL蛋白的结构,从而从根本上阐明4CL蛋白结构与功能之间的关系。
There is a 4CL gene family in most vascular plants. The different 4CL members which expressed differentially in plants participated in the different phenylpropanoid metabolism. The express of 4CL was mainly regulated by development stage, and it also was activated by many environmental factors such as damages, pathogenic intrusion and ultraviolet radiation. 4CL exists distinct substrate preference and specificities. The spatial restrictions of the binding groove rather than specific interactions between the substrate and amino acid residues of the polypeptide chain may be decisive in determining the substrate specificity of distinct 4CL isoenzymes. The two conserved peptide motifs in 4CL amino acid sequences observed by computer assisted sequence alignments were the Box Ⅰ motif, SSGTTGLPKGV, and the Box Ⅱ motif, GEICIRG. Antisense techniques of 4CL gene has been successfully applied to regulate the biosynthesis of the lignin in model plants such as Arabidopsis thaliana, Nicotiana tabacum and woody plant such as Populus tremuloides, Populus tomentosa. The future researches of 4CL should be emphasized particularly on the following aspects. More 4CL genes of woody plants should be separated and characterized by more advanced techniques. The research on the improvement of lignin content of woody plants is expected especially. The crystallization system of the 4CL protein should be established and the structure of 4CL protein should be illuminated from atom scale so that the relation of the 4CL structure and function would be elucidated.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2007年第2期96-103,共8页
Scientia Silvae Sinicae
基金
国家重大基础研究计划(G1999016005)资助
