AtPIN4 Mediates Sink-Driven Auxin Gradients and Root Patterning in Arabidopsis

Abstract

In contrast to animals, little is known about pattern formation in plants. Physiological and genetic data suggest the involvement of the phytohormone auxin in this process. Here, we characterize a novel member of the PIN family of putative auxin efflux carriers, Arabidopsis PIN4, that is localized in developing and mature root meristems. Atpin4 mutants are defective in establishment and maintenance of endogenous auxin gradients, fail to canalize externally applied auxin, and display various patterning defects in both embryonic and seedling roots. We propose a role for AtPIN4 in generating a sink for auxin below the quiescent center of the root meristem that is essential for auxin distribution and patterning.

Identification of factors required for m6A mRNA methylation in Arabidopsis reveals a role for the conserved E3 ubiquitin ligase HAKAI

“…The quantitative analysis of protoxylem phenotypes was performed on fuchsin‐stained roots as described (Bishopp et al ., 2011). Lugol staining for columella starch granules was carried out as described previously (Friml et al ., 2002). For the confocal laser scanning microscopy, a Zeiss LSM 780 microscope was used.…”

Isolation, Characterization, and Pericycle-Specific Transcriptome Analyses of the Novel Maize Lateral and Seminal Root Initiation Mutant rum1

“…Experiments with auxin transport inhibitors in Arabidopsis have demonstrated that the auxin movement from the shoot toward the root tip is responsible for lateral root development (Reed et al, 1998), while auxin movement away from the root tip is required for gravitropism and primary root elongation (Rashotte et al, 2000), although involvement of basipetal auxin transport in lateral root formation has also been discussed recently (Casimiro et al, 2001). Several genes involved in auxin transport, including the postulated efflux carriers of the pin family (Gälweiler et al, 1998;Mü ller et al, 1998;Friml et al, 2002aFriml et al, , 2002b, the auxin importer aux1 (Marchant et al, 1999), and the postulated efflux carriers pgp1, pgp2, and pgp19 (Noh et al, 2001), have been cloned recently in Arabidopsis. The maize ortholog of pgp1 is not expressed in roots (Multani et al, 2003).…”

Isolation and functional analysis of a Brassica juncea gene encoding a component of auxin efflux carrier

“…Researches on the function, expression pattern and location of recently isolated auxin carriers [18], [21][22][23], [26] have provided a great wealth of date for understanding the physiological role of auxin and polar auxin transport during plant development. Till now, around 8 different pin-like genes have been found in Arabidopsis genome and a few homologous genes from rice as well.…”

“…Agrobacterium strain LBA4404 and GV3101 were used for leaf disc transformation of Nicotiana tobacum cv Gx-1 and floral dip transformation of Arabidopsis thaliana C24 [27,28]. Brassica juncea and tobacco plants were grown in the green house with a 12 h light (26 ) and 12 h dark (20 ) period. Arabidopsis plants were grown in a phytotron in soil with a 16 h light (22 ) and 8 h dark (15 ) period.…”

“…To date several genes encoding auxin efflux carriers, Atpin1 [1][21], Atpin2/eir 1 [22], [23], and Atpin4 [26], have been isolated and some genes encoding PIN-like proteins were detected from Arabidopsis genome. We are interested in the function of auxin and polar auxin transport on plant development.…”