Physic nut (Jatropha curcas) is a perennial, oily seed-bearing plant belonging to the family Euphorbiaceae. It is a promising renewable feedstock for biodiesel and bio-jet fuel production. Intensive research efforts have been aimed at improving Jatropha growth and yield performance and enhancing beneficial traits.Although there have been many reports describing gene expression analysis under various experimental conditions using different reference genes (18S or actin) by semi-quantitative RT-PCR or RT-qPCR in Jatropha, a comparison of the different reference genes in Jatropha has not yet been reported.
Prof. XU Zengfu and his team of Xishuangbanna Tropical Botanical Garden (XTBG) evaluated the expression stability in Jatropha of 11 typical candidate reference genes by real-time quantitative polymerase chain reaction(RT-qPCR) among tissues at different developmental stages and under different abiotic stress treatments. Their study represented the first attempt to select a set of commonly used candidate reference genes in Jatropha for the normalization of gene expression data using RT-qPCR.
Their results indicated that more than one reference gene was preferred and that different reference genes should be selected according to the different sample type. According to the results calculated using the qBasePLUS software, the best combinations of reference genes for the normalization of gene expression profiles in Jatropha were as following: actin + GAPDH + EF1α for all developmental stages; actin + TUB8 for the vegetative stage; GAPDH + EF1α for the reproductive stage; actin + GAPDH + TUB5 for desiccation and cold stress treatments; TUB5 + TUB8 for desiccation stress treatment; and GAPDH + actin for cold stress treatment.
The results obtained in their study provided information that would ensure more accurate RT-qPCR-based gene expression quantification in Jatropha.