Translation and its regulation play an important role in plant adaptation. Ribosomes
have traditionally been considered passive molecular players regarding which RNA
to translate. However, this view is changing due to studies showing that specific and
heterogeneous ribosomes can have an active role regulating the translation of
different RNA subpools in mammals and bacteria (Genuth & Barna, 2019). In plants,
the possibilities for specialization are much higher, as each ribosomal family is
encoded by two to seven paralogs and there are several hints in the literature
pointing towards differential paralog roles. However, whether this heterogeneity
provides selective translation of specific mRNAs under particular cell conditions has
yet to be demonstrated.
To address this question, we are characterizing two ribosomal families, RPL10 and
RPL24, which contain three and two paralogs, respectively, and that are ubiquitously
expressed in Arabidopsis. Specific functions have been described for at least one
paralog of each family and paralog mutants show different phenotypes as well
(Falcone Ferreyra et al., 2020; Zhou et al., 2010)
We will provide evidence of phenotypic variance between paralog mutants in families
RPL10 and RPL24 under control and abiotic stress conditions. To determine if these
phenotypes are due to different RNA populations being translationally affected in
each mutant, we have performed RNA-seq from total and polysomal RNA from WT
and mutant plants. In addition, we are studying mutant complementation by
Recombineering (Brumos et al, 2020), leveraging the system to exchange exons
between paralogs maintaining each other ́s regulatory elements therefore shedding
light on whether they are functionally equivalent. We will present our progress
regarding these objectives.