Abstract:

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 AP 1. 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 (P<0.01) 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 AP 1 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.

Key words: genechip, multi-stems, plant morphogenesis, Arabidopsis thaliana