Galactinol synthase transcriptional profile in two genotypes of Coffea canephora with contrasting tolerance to drought.

Tiago Benedito Dos Santos,Carmen Lucia de Oliveira Petkowicz,Luiz Gonzaga Esteves Vieira,Douglas Silva Domingues,Rogério Barbosa de Lima,Luiz Filipe Protasio Pereira,Getúlio Takashi Nagashima,Valéria Carpentieri-Pípolo

doi:10.1590/s1415-475738220140171

Abstract

Increased synthesis of galactinol and raffinose family oligosaccharides (RFOs) has been reported in vegetative tissues in response to a range of abiotic stresses. In this work, we evaluated the transcriptional profile of a Coffea canephora galactinol synthase gene (CcGolS1) in two clones that differed in tolerance to water deficit in order to assess the contribution of this gene to drought tolerance. The expression of CcGolS1 in leaves was differentially regulated by water deficit, depending on the intensity of stress and the genotype. In clone 109A (drought-susceptible), the abundance of CcGolS1 transcripts decreased upon exposure to drought, reaching minimum values during recovery from severe water deficit and stress. In contrast, CcGolS1 gene expression in clone 14 (drought-tolerant) was stimulated by water deficit. Changes in galactinol and RFO content did not correlate with variation in the steady-state transcript level. However, the magnitude of increase in RFO accumulation was higher in the tolerant cultivar, mainly under severe water deficit. The finding that the drought-tolerant coffee clone showed enhanced accumulation of CcGolS1 transcripts and RFOs under water deficit suggests the possibility of using this gene to improve drought tolerance in this important crop.

Highlights

In Brazil, the cultivation of Conilon and Robusta coffee
We describe a comparative gene expression analysis of a C. canephora isoform (CcGolS1) most similar to C. arabica GolS1, in two genotypes of C. canephora that differ in water deficit tolerance
Galactinol synthase (GolS) orthologs and paralogs have been studied in several plant species, e.g., Ajuga reptans (Sprenger and Keller, 2000), A. thaliana (Taji et al, 2002), C. arabica, Gossypium hirsutum (Zhou et al, 2012), Populus trichocarpa (Zhou et al, 2014) and Xerophyta viscosa (Peters et al, 2007), and in most cases are associated with multiple developmental and environmental responses

Summary

Introduction

In Brazil, the cultivation of Conilon and Robusta coffee In contrast to Arabica coffee (Coffea arabica), C. canephora exhibits a broad range of drought tolerance. Lection of the Institute for Research and Rural Assistance of Espírito Santo State (INCAPER), Brazil (Ferrão et al, 2000a). Some of these accessions have been well characterized with regard to the physiological and molecular mechanisms involved in their tolerance to water deficit (DaMatta et al, 2003; Pinheiro et al, 2005; Praxedes et al, 2006; Marraccini et al, 2012; Vieira et al, 2013)

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Conclusion