To branch or not to branch: the role of pre-patterning in lateral root formation

Abstract

The establishment of a pre-pattern or competence to form new organs is a key feature of the postembryonic plasticity of plant development, and the elaboration of such pre-patterns leads to remarkable heterogeneity in plant form. In root systems, many of the differences in architecture can be directly attributed to the outgrowth of lateral roots. In recent years, efforts have focused on understanding how the pattern of lateral roots is established. Here, we review recent findings that point to a periodic mechanism for establishing this pattern, as well as roles for plant hormones, particularly auxin, in the earliest steps leading up to lateral root primordium development. In addition, we compare the development of lateral root primordia with in vitro plant regeneration and discuss possible common molecular mechanisms.

Nitrate foraging by Arabidopsis roots is mediated by the transcription factor TCP20 through the systemic signaling pathway

“…Altogether these results strongly indicate that TCP20 is part of the systemic signaling pathway that controls root foraging. For future work, it will be interesting to determine if other members of the TCP family play a role in lateral root development in general (71) and in root foraging in particular.…”

Plant roots use a patterning mechanism to position lateral root branches toward available water

“…In Arabidopsis, the developmental steps involved in LR patterning have been well defined (12). Previous studies have clearly shown that environmental stimuli can affect the initiation and emergence of LRs (1); however, evidence is lacking regarding an earlier role.…”

SUPPRESSOR OF GAMMA RESPONSE1 Links DNA Damage Response to Organ Regeneration

“…In contrast, the restoration of primary root tip growth seems most cost beneficial (and evolutionarily favorable) in the case of an acute and transient exposure to DNA damage, which is the case for seeds upon imbibition, where they acutely experience the DNA damage they accumulated during aging (Waterworth et al, 2015(Waterworth et al, , 2016. Regeneration of the embryonic root in response to DNA damage is critical for the viability of a germinating seed, as the linear-growing embryonic root carries no additional root primordia (Van Norman et al, 2013). We propose that SOG1, a gene unique to seed-bearing plants (Yoshiyama, 2016), may have evolved to salvage the overall mitotic competency (prevent permanent mitotic arrest) of the embryonic root during the germination of aged seeds.…”