Analysis of the molecular motif for inducing response to jasmonic acid and ethylene in Pib promoter via rice transformation
Pib启动子中茉莉酸和乙烯响应元件的转基因分析

The expression of Pib gene in rice was induced by hormone, such as jasmonic acid and ethylene. In order to determine the necessary regions of sequence or motifs for response to jasmonic acid and ethylene in Pib promoter, the full length promoter of Pib (-3 572~2 bp) and three different 5′ deletion fragments of Pib promoter (-2 692~2 bp, -1 335~2 bp, -761~2 bp) were synthesized by PCR and then were substituted for 35S upstream gus in a binary plasmid to construct re-combined plasmids of Pib promoter-gus fusions. Transgenic rice plants of the four recombined plasmids were produced by Agrobacterium-mediated transformation. Quality and quantum analysis of gus activities in transgenic plants at both protein and mRNA levels were conducted. The promotion activity of the full length promoter of Pib (-3 572~2 bp, pNAR901) was the highest in the four recombinants and the gus activities in its transgenic plant organs were enhanced obviously at 6 h after treatment with jasmonic acid or ethylene. The promotion activity of the deleted Pib promoters was significantly decreased and the response to jasmonic acid or ethylene treatment was not present when the -3 572~-2 692 bp sequence was knocked out from the Pib promoter. Although the disparity in the lengths of the deleted Pib promoter of pNAR902 (-2 692~2 bp), pNAR903 (-1 335~2 bp), and pNAR904 (-761~2 bp) was more than 2 or 3 times, the response to jasmonic acid or ethylene treatment was not different among their transgenic plants. All these results indicated that the common deleted sequences (-3 572 ~-2 692 bp) in the three deleted Pib promoter constructs were the essential region to the response to jasmonic acid and ethylene treatment. The result of pib promoter sequence searching indicated that there was only one GCCGCC motif at -2 722 bp of this common deleted segment in the Pib promoter sequence. Our rice transgenic results showed that the GCCGCC may be a cis-motif for Pib gene conferring response to jasmonic acid and ethylene for Pib gene.