Differentially expressed transcripts related to height in oil palm

A subtractive cDNA library was constructed using MPOB Planting Series 1 (PS1) population to isolate differentially expressed transcripts associated with height increment in oil palm. After differential screening, 98 clones were identified to be potentially positive with cDNA inserts ranging from 250 to 1000 bp. A total of 123 sequences generated and low quality sequences ≤20 were eliminated using Phred program to assess the sequence quality and determine the accurate consensus sequence. Contig assembly by CAP3 program generated 51 contigs and four singletons (55 unigenes). Blast search showed 49 unique sequences had significant match to various plant species in the GeneBank database with E-value ≤1e-5, and four sequences showed no significant similarity. Gene ontology analysis output from Blast2 GO program revealed that the sequences encoding for auxin responsive protein, circadian clock-associated protein1, zinc-finger protein and basic leucine zipper protein were potentially associated to dwarfism. The genes were identified based on their putative functions in regulating height in plants, particularly in growth hormone biosynthesis such as auxin (Aux/IAA), gibberellins (GA) and brassinosteroids (BR)

An in vitro study of the antifungal activity of Trichoderma virens 7b and a profile of its non-polar antifungal components released against Ganoderma boninense

Ganoderma boninense is the causal agent of a devastating disease affecting oil palm in Southeast Asian countries. Basal stem rot (BSR) disease slowly rots the base of palms, which radically reduces productive lifespan of this lucrative crop. Previous reports have indicated the successful use of Trichoderma as biological control agent (BCA) against G. boninense and isolate T. virens 7b was selected based on its initial screening. This study attempts to decipher the mechanisms responsible for the inhibition of G. boninense by identifying and characterizing the chemical compounds as well as the physical mechanisms by T. virens 7b. Hexane extract of the isolate gave 62.60% ± 6.41 inhibition against G. boninense and observation under scanning electron microscope (SEM) detected severe mycelial deformation of the pathogen at the region of inhibition. Similar mycelia deformation of G. boninense was observed with a fungicide treatment, Benlate® indicating comparable fungicidal effect by T. virens 7b. Fraction 4 and 5 of hexane active fractions through preparative thin layer chromatography (P-TLC) was identified giving the best inhibition of the pathogen. These fractions comprised of ketones, alcohols, aldehydes, lactones, sesquiterpenes, monoterpenes, sulphides, and free fatty acids profiled through gas chromatography mass spectrometry detector (GC/MSD). A novel antifungal compound discovery of phenylethyl alcohol (PEA) by T. virens 7b is reported through this study. T. virens 7b also proved to be an active siderophore producer through chrome azurol S (CAS) agar assay. The study demonstrated the possible mechanisms involved and responsible in the successful inhibition of G. boninense