Long terminal repeats (LTR) and transcription factors regulate PHRE1 and PHRE2 activity in Moso bamboo under heat stress

Abstract

LTR retrotransposons play a significant role in plant growth, genome evolution, and environmental stress response, but their regulatory response to heat stress remains unclear. " "We have investigated the activities of two LTR retrotransposons, PHRE1 and PHRE2, of moso bamboo (Phyllostachys edulis) in response to heat stress. " "The differential overexpression of PHRE1 and PHRE2 with or without CaMV35s promoter showed enhanced expression under heat stress in transgenic plants. " "The transcriptional activity studies showed an increase in transposition activity and copy number among moso bamboo wild type and Arabidopsis transgenic plants under heat stress. " "Comparison of promoter activity in transgenic plants indicated that 5'LTR promoter activity was higher than CaMV35s promoter. " "Additionally, yeast one-hybrid (Y1H) system and in planta biomolecular fluorescence complementation (BiFC) assay revealed interactions of heat-dependent transcription factors (TFs) with 5'LTR sequence and direct interactions of TFs with pol and gag. " "Our results conclude that the 5'LTR acts as a promoter and could regulate the LTR retrotransposons in moso bamboo under heat stress.