To accelerate the process of the transgenic breeding of Jatropha (a potential oilseed plant for renewable biodiesel production), many efforts have been made to establish a genetic transformation system to analyze gene expression patterns and functions. However, few studies have evaluated promoters in Jatropha. 
Prof. XU Zengfu and his team of Xishuangbanna Tropical Botanical Garden (XTBG) conducted a study to isolate a reproductive tissue-specific promoter in Jatropha. Because Jatropha curcas APETALA1 (JcAP1) was shown to be flower-specific, they isolated its 5′-flanking region as a tissue-specific promoter and characterized the region in transgenic Arabidopsis and Jatropha.
 The JcAP1 promoter showed marked activity in inflorescence buds in both transgenic Arabidopsis and Jatropha, which was consistent with the JcAP1 expression pattern in Jatropha. Through deletion analysis, they found that the −1313/−1057 region was essential for JcAP1 promoter activity in inflorescence buds. In addition, they identified a CArG box in the region, which was an important element mediating the regulatory effect of MADS-box proteins. The JcAP1 promoter was unexpectedly active in regions beyond the flowers, showing a high expression level in the seeds of transgenic Jatropha.
 The findings indicated that the cooperation of multiple cis-acting elements in the JcAP1promoter was required to confer accurate activity in transgenic plants. Although the 1.5 kb JcAP1 promoter did not exhibit the same expression pattern in transgenic Arabidopsis and Jatropha as was observed for JcAP1mRNA in Jatropha plants, that region could be used as a reproductive tissue-specific promoter in transgenic studies of Jatropha.
The study entitled “Isolation and characterization of the Jatropha curcas APETALA1 (JcAP1) promoter conferring preferential expression in inflorescence buds” has been published online in Planta.

Contact
Prof. XU Zengfu Ph.D Principal Investigator
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, Yunnan, China
E-mail: zfxu@xtbg.ac.cn
Tel: +86 691 8713051

Histochemical GUS staining of transgenic Arabidopsis harboring the JcAP1:GUS fusion.

 a, b Inflorescence buds, c flowers.

 AI apical inflorescence buds, LI lateral inflorescence buds, An anthers.

(Images by TAO Yanbin)