Open Access Highly Accessed Research article

Identification of drought-responsive genes in roots of upland rice (Oryza sativa L)

Aline R Rabello12, Cléber M Guimarães3, Paulo HN Rangel3, Felipe R da Silva1, Daniela Seixas4, Emanuel de Souza4, Ana CM Brasileiro1, Carlos R Spehar2, Márcio E Ferreira1 and Ângela Mehta1*

Author Affiliations

1 Embrapa Recursos Genéticos e Biotecnologia, PqEB Av W5 Norte Final, CEP 70770-900, Brasília, DF, Brazil

2 Universidade de Brasília, CEP 70910-900, Brasília, DF, Brazil

3 Embrapa Arroz e Feijão, Rodovia GO-462, km 12 Zona Rural C.P. 179 CEP 75375-000, Santo Antônio de Goiás, GO, Brazil

4 Universidade Federal do Paraná, Caixa Postal 19046, CEP 81531-990, Curitiba PR, Brazil

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BMC Genomics 2008, 9:485  doi:10.1186/1471-2164-9-485

Published: 15 October 2008

Abstract

Background

Rice (Oryza sativa L.) germplasm represents an extraordinary source of genes that control traits of agronomic importance such as drought tolerance. This diversity is the basis for the development of new cultivars better adapted to water restriction conditions, in particular for upland rice, which is grown under rainfall. The analyses of subtractive cDNA libraries and differential protein expression of drought tolerant and susceptible genotypes can contribute to the understanding of the genetic control of water use efficiency in rice.

Results

Two subtractive libraries were constructed using cDNA of drought susceptible and tolerant genotypes submitted to stress against cDNA of well-watered plants. In silico analysis revealed 463 reads, which were grouped into 282 clusters. Several genes expressed exclusively in the tolerant or susceptible genotypes were identified. Additionally, proteome analysis of roots from stressed plants was performed and 22 proteins putatively associated to drought tolerance were identified by mass spectrometry.

Conclusion

Several genes and proteins involved in drought-response, as well as genes with no described homologs were identified. Genes exclusively expressed in the tolerant genotype were, in general, related to maintenance of turgor and cell integrity. In contrast, in the susceptible genotype, expression of genes involved in protection against cell damage was not detected. Several protein families identified in the proteomic analysis were not detected in the cDNA analysis. There is an indication that the mechanisms of susceptibility to drought in upland rice are similar to those of lowland varieties.