The 30th International Conference on Arabidopsis Research (ICAR 2019)

612 / 2019-04-23 18:47:48

A transportome-scale amiRNA-based screen identifies redundant roles of Arabidopsis ABCB6 and ABCB20 in auxin transport

redundancy,,hormone,,auxin,,ABCB.

Plenary track > Hormones

Transport of signaling molecules is of major importance for regulating plant growth, development,
and responses to the environment. A prime example is the spatial-distribution of
auxin, which is regulated via transporters to govern developmental patterning. A critical
limitation in our ability to identify transporters by forward genetic screens is their potential
functional redundancy. Here, we overcome part of this functional redundancy via a transportome,
multi-targeted forward-genetic screen using artificial-microRNAs (amiRNAs). We
generate a library of 3000 plant lines expressing 1777 amiRNAs, designed to target closely
homologous genes within subclades of transporter families and identify, genotype and
quantitatively phenotype, 80 lines showing reproducible shoot growth phenotypes. Within
this population, we discover and characterize a strong redundant role for the unstudied
ABCB6 and ABCB20 genes in auxin transport and response. The unique multi-targeted lines
generated in this study could serve as a genetic resource that is expected to reveal additional
transporters.