OIL PALM MSP2 PROMOTER ISOLATION, IN SILICO ANALYSIS AND FUNCTIONAL CHARACTERISATION

Abstract

Arabidopsis was used as a stable transformation system to characterise the function of the oil palm mesocarp-specific promoter, MSP2. Five MSP2 promoter fragments ranging from 1558 bp to 3044 bp in size were successfully isolated. In silico sequence analysis showed various putative plant regulatory elements in the different MSP2 promoter regions. Two vector constructs containing MSP2-GLC and MSP2-GLG promoter fragments were attached to beta-glucuronidase (GUS) reporter gene and transformed into Arabidopsis thaliana. Histochemical GUS staining of the transgenic Arabidopsis showed that both promoter fragments were expressed in the flower, especially in petal and stigma, silique for MSP2-GLC and in anther and stamen for MSP2-GLG. The QELEMENTZMZM13 motif present only in the MSP2-GLG fragment is likely vital for the anther-specific expression. In MSP2-GLC transgenic Arabidopsis, GUS expression was enhanced under cold conditions, unlike MSP2-GLG transgenic Arabidopsis. A low-temperature response (LTR) motif present in MSP2-GLC may be important to enhance and drive the expression of a transgene under cold conditions. The deleted region in MSP2-GLG fragment caused the removal of the LTR motif, which most likely indicates that the size of the promoter is not necessarily important to drive gene expression, but the availability of a specific motif is key to determine its strength and specificity.