Transcription Factors Associated with Abiotic Stress and Fruit Development in Oil Palm

Abstract

Oil palm is the most productive oil crop which plays a key role in meeting current and future demand for vegetable oil. Palm oil has a multitude of edible and nonedible applications and it is an important contributor to the economy of a few countries in the Southeast Asian region such as Malaysia, Indonesia, and Thailand. Water, temperature, and nutritional stresses are identified as key factors suppressing oil palm productivity. Addressing issues in key biological processes such as fruit development and responses to abiotic stress is essential in oil palm genetic improvement efforts. Gene expression at the transcriptional level is mainly regulated by transcription factors (TFs) which mediate cellular signaling responses and coordinate expression of biosynthetic pathway genes. Several transcription factors of the APETALA2/ethylene response factor (AP2/ERF) family including from the AP2 and ERF subfamilies have been identified to be involved in fruit ripening while the dehydration responsive element-binding 1 (DREB1)/C-repeat-binding factor (CBF) subfamilies are associated with abiotic stress response in oil palm. Their expression profiles have been studied in oil palm tissues at different stages of development and in response to various phytohormones and abiotic factors as well as in transgenic tomato as a model system. Their DNA binding abilities to specific motifs in stress-responsive and fruit ripening associated genes have been characterized through yeast one-hybrid and electrophoretic mobility shift assay (EMSA). This chapter also looks at other transcription factor families that have been shown to regulate these important biological processes in oil palm. The potential applications of the transcription factors for crop improvement efforts are discussed.