The role of RNA polymerase II transcript elongation factors in plant stress responses

Abstract

The elongation phase is a dynamic and highly regulated step of the RNA polymerase II (RNAPII) transcription cycle. A variety of transcript elongation factors (TEFs) comprising regulators of RNAPII activity, histone chaperones, and modulators of histone modifications assist transcription through chromatin. Thereby, TEFs substantially contribute to establish gene expression patterns during plant growth and development. Beyond that, recent research indicates that TEFs and RNAPII transcriptional elongation also play a key role in plant responses to environmental cues. Thus, certain TEFs (i.e. PAF1C, FACT, and TFIIS) were found to mediate transcriptional reprogramming by different mechanisms to establish plant tolerance to abiotic conditions such as heat stress and elevated salt concentrations. Hence, TEFs govern RNAPII elongation to generate the transcriptional output adequate for distinct environments. It is to be expected that future research in this developing field will reveal that TEFs are involved in a growing number of plant responses to changing environmental conditions.

Keywords: Arabidopsis; PAF1C; RNA polymerase II; SPT16; SSRP1; TFIIS; chromatin; nucleosome; transcription.