The Effects of Transcription Factor ABP9 over-expression on Plant Growth and Development

Meng Hui1,2, Zhang Xia2, Zeng Rizhong1, Fan Yunliu2, Zhao Jun2 (1Rubber Research Institute, CATAS, Danzhou Hainan 571737; 2Biotechnology Research Institute, National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy Agricultural Sciences, BeiJing 100081)

Transcription factor ABP9, ABRE, ABA, Plant growth and development

[OBJECTIVE]In order to analyze the effects on plant growth and development of over-expressing ABP9, an ABA/stress-responsive transcription factor gene from maize, aiming at genetic engineering crops for abiotic stress tolerance,[METHOD]an plant expression vector on which the expression of ABP9 is driven by 35S promoter was constructed and transgenic Arabidopsis lines over-expressing ABP9 were obtained. The morphological, developmental, physiological and gene expression changes in transgenic plants comparing to wild type were analyzed at germination, vegetative and reproductive growth stages.[RESULTS]The results showed that under normal growth conditions, comparing to that of wild type plants, the growth and development of transgenic plants was delayed at germination, seedling growth and flowering stages; the stomata pores and leaf ABA levels reduced; the expression of genes involved in ABA signaling increased whereas that of ABA biosynthetic genes decreased. All of the effects are positively correlated with the expression levels of ABP9.[CONCLUSION]The data indicates that ABP9 over-expression induces stress responses in transgenic plants even under normal growth conditions and retards growth and development. This suggests that the timing and levels of ABP9 expression should be tightly controlled when using it to improve plant stress tolerance.