Cloning and Expression Pattern Study of NIP5;1, a Boron Transport Gene in Tenera Oil Palm

Abstract

Boron (B) is an essential micronutrient required for plant growth and development. In Thailand, boron deficiency is the major problem in oil palm (Elaeis guineensis Jacq.) plantation, causes abnormal leaves and abortion of fruit which lead to decrease of crop yield. In recent year, the channels for boric acid mediate boron uptake under boron deficiency (NIP5;1) had been identified in many plant species. The NIP5;1 gene encodes a member of major intrinsic protein (MIPs) family also known as aquaporin. The objectives of this study were to clone full length of EgNIP5;1 gene and to study of expression pattern of EgNIP5,1 gene in oil palm during boron deficiency, sufficiency, and toxicity treatments using real–time PCR technique. In this study, we cloned an NIP5;1 like gene (named as EgNIP5;1) from Tenera oil palm. The full length of EgNIP5;1 was 894 bp and encoded a protein of 297 amino acid residues. Sequence analysis showed the EgNIP5;1 was highly conserved with NIPs gene in other plant species such as Arabidopsis, rice, citrus and maize. The phylogenetic tree analysis indicated that EgNIP5;1 protein belonged to NIPs subgroup II. For the expression pattern analysis, root samples were collected randomly at 7, 14, 28 and 56 days after boron treatments. Total RNA was extracted and the cDNA was synthesized. The specific primers were designed and real–time PCR was performed. For the result, the EgNIP5;1 expression levels in root were induced and increased continuously to 3 and 2 folds at 14 day after boron deficiency and boron toxicity treatment, respectively as compared with that 0 day and the expression levels were decreased after that.