利用基因芯片筛选影响茎分化的相关基因

Application of Genechip in Screening the Stem Differentiation-Related Genes

顶端分生组织的分化影响茎及根的生长,从而形成具有不同形态的植株,拟南芥因其在适当条件下与木本植物分生组织分化以及次生生长的共性而被运用到研究当中。花异常株系(AFDL)由于AP1表达的显著降低导致分枝增多。用拟南芥基因芯片对AFDL的幼苗进行基因表达分析,结果显示在临近抽薹期,AFDL与野生型相比有111个变化倍数大于2且P<0.01的基因;其中大部分参与对外界环境及内源刺激的感知和应答,表明AP1下降可能是由于植株对内外环境刺激的过度反应所导致。从基因芯片中挑选出表达量变化显著的2个基因,分别构建相应的植物表达载体并转化拟南芥,其中AT1G56300基因的超表达植株及AT1G65490基因的抑制表达植株都出现了多茎融合、真叶萌发延迟且生长缓慢的表型,并且转基因植株的基因表达变化趋势与性状强弱程度相对应。上述结果初步表明这2个基因能影响茎的分化并作用于最终的形态建成。

The apical meristem differentiation influences the stem and root development,and the plant morphogenesis.In this study,Arabidopsis thaliana was used to investigate the stem secondary growth because it has similar meristem differentiation and secondary growth as woody species do.An Abnormal Flower Development Line（AFDL） produces more branches because of the remarkably reduced expression of AP1.The genechip was used to identify the differentially expressed genes in this study,and the result showed that there were 111 genes whose changes were more than two folds（P0.01） in the AFDL compared to wild-type before bolting.Most of these genes were involved in responses to the internal and the environmental stimulations.It was indicated that reduction in AP1 expression of AFDL was due to the excessive response to the stimulations.Two genes with remarkable changes in their expression were chosen from the genechip analysis,the expression vectors were constructed,and they were transferring to Arabidopsis thaliana via GV3101.The overexpression transplants of AT1G56300 and the RNAi transplants of AT1G65490 showed a phenotype of multi-stems stacked or caespitose stems.In addition,the euphylla development was postponed.The gene expression in these transgenic plants was measured by RT-qPCR,and the level of genes in different line was coincidence with their phenotype.Our results indicated that the two genes would be related to the development and differentiation of the stem and play a role in the plant morphogenesis.