249Ann. appl. Biol. (2004), 144:249-250Printed in UK

*Corresponding Author E-mail: p.lea@lancaster.ac.uk

© 2004 Association of Applied Biologists

Improving resistance to drought and salinity in plants

By P J LEA1*, M A J PARRY2 and H MEDRANO3

1Biological Sciences, Lancaster University, Lancaster LA1 4YQ, UK2Crop Production and Improvement, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK

3Laboratori de Fisiologia Vegetal, Departament de Biologia ,Universitat de les Illes Balears, 07071Palma de Mallorca, Spain

(Accepted 17 May 2004; Received 13 May 2004)

As has been reported previously (Parry et al.,2004), a European Commission sponsoredconference on the �Optimisation of Water Use byPlants in the Mediterranean, OPTIMISE� (INCO-MED ICA3-CT-2002-50005) was held in Palma deMallorca, Balearic Islands, Spain in March 2003.

Water is a scarce commodity in Mediterraneancountries. Agriculture accounts for 75% of the totalwater consumption, but drought is the majorlimitation for growing many crops. The predictedchange in climate, greater use through tourism,industrialisation and salinisation of water supplies,will further exacerbate the situation (Araus, 2004;Clary et al., 2004). There is therefore an importantrequirement to improve the drought and salinitytolerance of agricultural crops.

Considerable advances have been made in theselection of crop varieties that are able to toleratedrought and salinity. These have been throughtraditional breeding (Araus et al., 2003; Munns etal., 2003; Slafer, 2003), mutant selection (Mahar etal., 2003; Ahloowalia et al., 2004) and more recentlyQTL analysis (Baum et al., 2003; Thomas 2003;Foolad, 2004; Forster et al., 2004; Talamè et al.,2004). The identification of wild relatives (e.g.Porteresia coarctata for rice) that are able to growin saline soils, may also provide a useful supply ofnew germplasm for future breeding (Latha et al.,2004).

Molecular approaches have identified a largenumber of genes that are induced following theapplication of drought or saline conditions. Thesegenes and the proteins that they encode can bedivided into three categories: (1) signalling andtranscriptional control; (2) the protection ofmembranes and proteins and (3) water and iontransport (Shinozaki et al., 2003; Wang et al., 2003).As a result of these studies there have been a numberof attempts to genetically manipulate plants tobecome more tolerant to drought and salinitystresses. Potential candidate genes have includedthose encoding: (1) transcription factors; (2)compatible solutes (e.g. proline); (3) antioxidantsand detoxifying enzymes; (4) ion transport and (5)heat shock and late embryogenesis abundantproteins. A number of articles have discussed atlength the results obtained from the laboratory testing

of transgenic plants containing such potentiallyuseful genes (Yoshida 2002; Chaves et al. 2003;Figueras et al., 2004). As yet we are awaitingevidence from major field trials, to establish if suchgenetic manipulation will eventually lead to usefuldrought and salinity tolerant crop plants that are safeand acceptable to the public.

Acknowledgements

The OPTIMISE workshop was supported by theEuropean Commission INCO-MED programmecontract ICA3-CT-2002-50005. RothamstedResearch receives grant-aided support from theBiotechnology and Biological Sciences ResearchCouncil (BBSRC).

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