Differential expression gene profiling studies on trunking and non-trucking sago palm (Metroxylon sagu rottb.)

• Main Author: Anastasia Shera, Edward Atit
• Format: Thesis
• Language: English
• Published: Universiti Malaysia Sarawak (UNIMAS) 2013
• Subjects: Q Science (General); QK Botany
• Online Access: http://ir.unimas.my/id/eprint/9378/1/Anastasia%20Shera%20Binti%20Edward%20Atit%20ft.pdf; http://ir.unimas.my/id/eprint/9378/
• Institution: Universiti Malaysia Sarawak

In the vast peat land cultivated with sago palm in Sarawak, a considerable amount of cases involving stunted palms is noted in the plantations. Despite being a survivor in such adverse condition, these sago palms were found to be unable to form trunks. Research using PCR-based differential display analysis on leaf samples of selected sago palm showed distinct transcript pattern for normal trunking palm and non-trunking palm samples. Differentially expressed transcripts (DETs) with varying levels of expression were isolated from comparison of the trunking and non-trunking transcript profiles, and later identified. While most are found to be un-annotated sequences, the DETs with identified functions can be generally grouped under the functions related to energy metabolism, nutrient regulation, biosynthetic reactions, defense mechanism and stress tolerance. T sample showed higher expression of redox regulating functions through ascorbate peroxidase and glycerol kinase while NT sample had proteins actively involved in the respiratory chain and chloroplast regulation. The proteins involved were encoded by DETs with differences in transcript intensity of 47% to 123%, between T and NT. In nutrient regulation, T sample had active utilization of nitrogen (N), and regulation of phosphate (P) and cobalt (Co), whereas NT had active uptake of N and regulation of calcium (Ca), magnesium (Mg) and zinc (Zn). The proteins involved were encoded by DETs with differences in transcript intensity of 35% to 123%, between T and NT. Other DETs identified in T sample, had biosynthetic roles related to defense and growth regulation, and difference of 16% to 65% in band intensity value. As for NT sample, other proteins are found to function in regulating trafficking and signaling roles. Their intensity values in NT sample were over twofold the values for T. DETs containing only un-annotated sequences had at least 46% difference in band intensity between samples. The identities of the un-annotated DETs and their contributory roles in the trunk formation or lack of, in sago palms remain open to future studies.