Partial isolation of distal promoter sequence of the NPR1 gene from local chilli Pepper [Capsicum annuum L.] genotype berangkai

Abstract

Understanding of NPR1gene expression is a crucial aspect in improvement of chilli pepper resistant. The NPR1 gene is known to confer broad spectrum resistance toward many phytopathogens by activating SARmechanism. For that reason, characterization of the NPR1-gene promotor is necessary. The distal promoter of the NPR1-gene in general is characterized by the presence of enhancer, silencer, and cis-acting elements, located 5,950 bp from the ATG starting point. Therefore this study is focused to the isolateion of the distal promoter sequence of the NPR1 gene from a local Capsicum annul L. Genotype Berangkai. Specific primer pairs designatedas PD-CbNPR1-F1 [FR] and PD-CbNPR1-F2 [FR] were designed to amplify the whole targeted segments. However, only 1,873 bp in total [31.5 %] of sequences could successfully be elucidated from the first round, covering 970 and 993 bp from its upstream and downstream segments respectively. Hhomology analysis using BLAST tool successfully confirmed 99 and 100 % homology with its reference sequence derived from cv. Zunla-1. These result indicated that the NPR1 distal promoter sequence is successfully isolated from chilli pepper [Capsicum annuum L] genotype Berangkai. However, ffurther analysis using primer walking strategy should be undertaken in order to identify the entire sequence of its promoter region.