The retrograde signals responsible for photoacclimation in the marine diatom Phaeodactylum tricornutum

Photoacclimation of unicellular algae allows for reversible changes in the number and/or effective absorption cross section of photosynthetic units on time scales of hours to days in response to changes in irradiance. The process involves an enigmatic signaling pathway from the plastid to the nucleus.Our results reveal, for the first time, a fundamental pathway of retrograde signal transduction in a eukaryotic photosynthetic alga. Phaeodactylum tricornutum mRNA profiles of low light (20 umol photons/m2/s) and high light (940 umol photons/m2/s) acclimated wild-type (WT) were generated by deep sequencing, in triplicate, using Illumina TruSeq. The most differentially expressed genes were targeted by RNA interference to identify genes of interest. Phenotypic characterization of resultant transformants along with RT-qPCR verification was conducted on applicable strains.