Phosphate (Pi) and its anhydrides constitute
major nodes in metabolism. Thus, plant performance depends directly on
Pi nutrition. Inadequate Pi availability in the rhizosphere is a common
challenge to plants, which activate metabolic and developmental
responses to maximize Pi usage and acquisition. The sensory mechanisms
that monitor environmental Pi and transmit the nutritional signal to
adjust root development have increasingly come into focus. Recent
transcriptomic analyses and genetic approaches have highlighted complex
antagonistic interactions between external Pi and Fe bioavailability and
have implicated the stem cell niche as a target of Pi sensing to
regulate root meristem activity.
Carbonell, A.; Flores, R.; Gago, S.
Trans -cleaving hammerhead ribozymes with tertiary stabilizing motifs: in vitro and in vivo activity against a structured viroid RNA Nucleic Acids Research 39, 2432-2444, (2011) DOI: 10.1093/nar/gkq1051
Trans -cleaving hammerheads with discontinuous or extended stem I and with tertiary stabilizing motifs (TSMs) have been tested previously against short RNA substrates in vitro at low Mg 2+ concentration. However, the potential of these ribozymes for targeting longer and structured RNAs in vitro and in vivo has not been examined. Here, we report the in vitro cleavage of short RNAs and of a 464-nt highly structured RNA from potato spindle tuber viroid (PSTVd) by hammerheads with discontinuous and extended formats at submillimolar Mg 2+ . Under these conditions, hammerheads derived from eggplant latent viroid and peach latent mosaic viroid (PLMVd) with discontinuous and extended formats, respectively, where the most active. Furthermore, a PLMVd-derived hammerhead with natural TSMs showed activity in vivo against the same long substrate and interfered with systemic PSTVd infection, thus reinforcing the idea that this class of ribozymes has potential to control pathogenic RNA replicons.