拟南芥木聚糖合成关键酶基因的调控研究

Studies on the regulation of xylan biosynthesis key enzyme genes in Arabidopsis thaliana

【目的】从目前已知的参与拟南芥Arabidopsis thaliana次生壁加厚生长的转录因子着手,分析这些次生壁相关的转录因子是否能够调控木糖合成关键酶基因FRA8、IRX9、IRX10、IRX14、F8H、IRX9-L、IRX10-L和IRX14-L的表达,并且观察KNAT7基因显性抑制植株的表型.【方法】通过Gateway技术构建效应器和报告器,进行瞬时转录激活试验,同样构建pCAMBIA1304-p35S∷KNAT7-SRDX重组质粒,用农杆菌Agrobacterium tumefaciens花序浸染法将此质粒转化到野生型拟南芥植株中.【结果和结论】瞬时转录激活试验表明,转录因子KNAT7、MYB46、ERF72、SND1、NST2能够激活多个拟南芥木聚糖合成关键酶基因的表达,其中KNAT7能促进基因FRA8、IRX9和IRX14-L的表达.KNAT7基因显性抑制能显著影响拟南芥的生长.试验结果表明KNAT7基因可能在木聚糖的合成中起着重要的调控作用.

Objective] To analyze whether some transcription factors in Arabidopsis thaliana, known for the secondary cell wall thicken , could regulate the expression of the key genes of xylosyltransferase , such as FRA8, IRX9, IRX10, IRX14, F8H, IRX9-L, IRX10-L and IRX14-L, and observe the phenotype of KNAT7 dominant repression plant .[Method] Effectors and reporters were constructed by Gateway Tech-nology and the transient transcriptional activation assay was conducted .Construct pCAMBIA1304-p35S∷KNAT7-SRDX recombinant plasmid by Gateway Technology and transform this plasmid into wild A.thali-ana via Agrobacterium tumefaciens-floral dip method .[Result and conclusion] The transient transcription-al activation assay revealed that transcription factors KNAT 7, MYB46, ERF72, SND1, NST2 could acti-vate the expression of a number of the key genes of xylosyltransferase .KNAT7 could activate the expres-sion of FRA8, IRX9 and IRX14-L.Furthermore, dominant repression of KNAT7 significantly affected the growth of Arabidopsis thaliana.These results indicate that KNAT7 probably plays an important role in the regulation of xylan biosynthesis .