EXPRESSION PROFILES OF CANDIDATE GENES ASSOCIATED WITH CYANOGENIC POTENTIAL IN CASSAVA AT DIFFERENT GROWTH STAGES
SUKHUMAN WHANKAEW
Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom 73170, Thailand
SUPAJIT SRAPHET
Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom 73170, Thailand
DUNCAN R. SMITH
Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom 73170, Thailand
KANOKPORN TRIWITAYAKORN *
Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom 73170, Thailand
*Author to whom correspondence should be addressed.
Abstract
The cyanogenic potential (CN) of cassava causes significant concerns with regards to both individual health and the well being of the environment. In order to obtain a better understanding of the genes mediating CN, this project aimed to determine the expression of candidate genes related to CN using real-time PCR. Transcription profiles of eight genes selected from a previously identified quantitative trait loci (QTL) were analyzed in low and high CN cassava plants at 6, 9 and 12 months after planting (MAP). The results showed that the majority of differentially regulated transcripts were expressed at a higher level in high CN plants as compared with low CN plants, and that this difference was primarily observed at 9 MAP. One discordant transcript (spermidine synthase) was expressed at higher levels in low CN plants than in high CN plants, and this may be related to CN detoxification. Overall our results support the contention that these genes are associated with determining CN potential, and the results may assist in developing low CN cassava for consumption and industrial applications.
Keywords: Cyanogen content, cassava, gene expression, real-time PCR