Relulation of salt stress responsive genes encoding ion transport proteins in Sugarcane by Macroarray assay
Ferreira, B.S.1; Branco, A.T. 1; Mattos, L.P. 1; Range, P.L.1; Lourenço, G.F. 1; Ferreira, M.S.1; Marques, V.C.L.3; Lima V.S. 3; Carneiro Júnior, J.B2; de Souza Filho G.A1-3.
1Lab. de Biotecnologia–CBB–UENF/Campos–RJ; 2Biofábrica–UFRRJ/ Campos-RJ; 3Núcleo de Análise Genomica–UENF/Campos–RJ
Salinity is an important limiting factor for agricultural production by causing two distinct stress in plants: hydric stress, caused by the greater difficulty of water absorption, and ionic stress, associated to the sodium ion effect on the diverse cellular functions, decreased nutrient absorption, enzyme activities, photosynthesis and metabolism.
The adaptation to saline stress is accompanied by alterations in the levels of numerous metabolites, proteins and mRNAs. Identification and analysis of genes related to ion transport in several plant species has help to understand the responses mechanisms of plant salt tolerance. For these studies the hybridization of cDNA arrays is a powerful way to evaluate the expression of thousands of genes in parallel. This work aimed to analysis of expression profile of genes involved in ion transport in salt stressed plants of sugarcane by macroarray assay. Data mining analyses of the Sugarcane Est Project (SUCEST) data bank allowed to identify 80 clusters for ion transporters. The frequency of the transcripts in the different cDNA libraries was analyzed by electronic northern. These cDNA clones were acquired from SUCEST and gene regulation was evaluated in sugarcane leaves and roots exposed to 150mM NaCl in two exposition times. Previous analyses of genes involved with ion transporters showed repression of transcription for the majority of the genes in leaf tissue. Preliminary results demonstrated high repression for LCT1 and VHATPase E subunit transcripts. In contrast, HAK/KUP, AKT1 and VHATPase G genes were induced by salinity. The expression regulation in root tissue shows that ion transport genes were poorly induced. Only some genes were considerable induction values, between them, AKT1, AVP1 and NHX1. The genes CLC1 and VHATPase F subunit presents an interesting expression profile, these genes were repressed in first 6h after the salt stress, and they show induction after 48h of exposition. Afterwards, analysis of these results by Northern blot will provide additional information about salt stress response in sugarcane.
Supported by FAPERJ, CAPES, FINEP, UENF.
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