关键词: OsBELL4A, 激素, 逆境胁迫, 冠根, WOX基因家族

Abstract: Root system not only plays an important supporting role to the shoot, but also is a main organ for plants to absorb water and nutrients. In order to study the role of BELL family factors in plant development, and response to environmental cues,  this study identified 4 BELL4 homologous genes in rice  through compassion with Arabidopsis. The elements of ABRE, GARE, ERE, ARE and DRE in their promoters were searched, which were possible responsive to stress and hormones. Real-time quantitative PCR analysis showed that the four BELL4 homologous genes were not only induced by drought, low temperature and salt stress, but also regulated by plant hormones, such as ethylene, gibberellin and abscisic acid, which indicating that these genes may respond to various hormones and stress in rice root. Further analysis with the phenotype of RNAi materials of OsBELL4A showed that inhibiting the expression of OsBELL4A could promote the expression level of WOX family genes, with inhibition of the primary root growth at the seedling stage of rice, but promote the number of crown roots. These results suggested that OsBELL4A might play an important regulatory role in rice root development and stress response.

Key words: OsBELL4A, hormone, stress, crown root, WOX gene family