Osmotic stress sensing in Populus: Components identification of a phosphorelay system

Chefdor, Françoise; Bénédetti, Hélène; Depierreux, Christiane; Delmotte, Francis; Morabito, Domenico; Carpin, Sabine

doi:10.1016/j.febslet.2005.11.051

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Volume 580, Issue 1 , Pages 77-81, 9 January 2006

Osmotic stress sensing in Populus: Components identification of a phosphorelay system

Edited by Francesc Posas

Laboratoire de Biologie des Ligneux et des Grandes Cultures (UPRES EA 1207), Faculté des Sciences, Université d’orleans, Rue de Chartres, BP6759, 45067 Orléans Cedex 2, France

Received 14 September 2005; received in revised form 21 November 2005; accepted 21 November 2005. published online 05 December 2005.

Abstract

To study the Populus response to an osmotic stress, we have isolated one cDNA encoding a histidine-aspartate kinase (HK1) and four cDNAs encoding histidine-containing phosphotransfer proteins (HPts), HPt1–4. The predicted HK1 protein shares a typical structure with ATHK1 and SLN1 osmosensors. The 4 HPTs are characterized by the histidine phosphotransfer domain. We have shown that HK1 is upregulated during an osmotic stress in hydroponic culture. We have detected an interaction between HK1 and HPt2, using the yeast two-hybrid system. These results suggest the existence of a multi-step phosphorelay pathway probably involved in osmotic stress sensing in Populus.

Keywords: Histidine-aspartate kinase, Histidine-containing phosphotransfer protein, Yeast two-hybrid analysis, Osmotic stress, Populus