Transgenerational effects of chromium stress at phenotypic and molecular
level in Arabidopsis thaliana
Abstract
In this work, we describe the results obtained in the model plant,
Arabidopsis thaliana, to investigate the transgenerational phenotypic
effects of chromium (Cr) stress. F1 generation from parents grown in
both acute and chronic stress showed significant higher levels of the
maximal effective concentration (EC50) than F1 from unstressed parents.
In addition, both F1 from Cr stressed parents showed higher germination
rate under Cr presence and F1 from parents cultivated under chronic
stress displayed reduction of hydroxide peroxide levels under Cr stress
compared to control. At lower Cr stress level, F1 resulted to promptly
activate more genes involved in Cr stress responses than F0 implying a
memory linked to a transgenerational priming. F1 modulated significantly
less genes than F0 at later stage and at higher Cr levels implying a
memory leading to Cr stress adaptation. Several members of bHlH
transcription factors were induced by Cr stress in F1 and not in F0,
such as bHlH100, ORG2 and ORG3. F1 optimized gene expression towards
pathways linked to iron starvation response. A model of transcriptional
regulation of transgenerational memory to Cr stress was developed and
eventually applied for other heavy metal stresses.