1 June 2016

Paper on transport of plant hormones published in Nature Communications

Publication

'The Arabidopsis NPF3 protein is a Gibberellin transporter' with postdoc Morten Egevang as shared first author and Hussam Nour-Eldin, Barbara Ann Halkier and Christoph Crocoll as co-authors was published in Nature Communications last week.

Gibberellins are plant hormones that promote a wide range of developmental processes.

While gibberellin signalling is well understood, little is known about how gibberellin is transported or how gibberellin distribution is regulated.

Quantification and distribution of fluorescently tagged gibberellins

Transport of gibberellins across cell membranes

In this paper four researchers from DynaMo, in collaboration with researhers from Israel, USA and Germany, utilize fluorescently labelled gibberellin to screen for Arabidopsis mutants deficient in gibberellin transport.

They show that the NPF3 transporter efficiently transports gibberellins across cell membranes in vitro and fluorescently labelled gibberellins in vivo.

NPF3 is expressed in root endodermis and repressed by giberellin. NPF3 is targeted to the plasma membrane and subject to rapid BFA-dependent recycling.

The antagonist of gibberellin

In the paper, the researchers show that abscisic acid, an antagonist of gibberellin, is also transported by NPF3 in vitro. Abscisic acid promotes NPF3 expression and fluorescently labelled gibberellin uptake in plants.

On the basis of these results, they propose that gibberellin distribution and activity in Arabidopsis is partly regulated by NPF3 acting as an influx carrier and that interactions between gibberellin and abscisic acid may occur at the level of transport.