AOBPreview originally published online on August 30, 2006
Annals of Botany 2006 98(5):965-974; doi:10.1093/aob/mcl189
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Expression Profiling of the 14-3-3 Gene Family in Response to Salt Stress and Potassium and Iron Deficiencies in Young Tomato (Solanum lycopersicum) Roots: Analysis by Real-time RT–PCR
1 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences Nanjing 210008, China
2 Graduate School of Chinese Academy of Sciences Beijing 100081, China
* For correspondence. E-mail wmshi{at}issas.ac.cn
Received: 12 May 2006 Returned for revision: 6 July 2006 Accepted: 21 July 2006 Published electronically: 30 August 2006
• Background and Aims Mineral nutrient deficiencies and salinity constitute major limitations for crop plant growth on agricultural soils. 14-3-3 proteins are phosphoserine-binding proteins that regulate the activities of a wide array of targets via direct protein–protein interactions and may play an important role in responses to mineral nutrients deficiencies and salt stress. In the present study, the expression profiling of the 14-3-3 gene family in response to salt stress and potassium and iron deficiencies in young tomato (Solanum lycopersicum) roots was investigated in order to analyse the 14-3-3 roles of the proteins in these abiotic stresses.
• Methods Sequence identities and phylogenetic tree creation were performed using DNAMAN version 4.0 (Lynnon Biosoft Company). Real-time RT–PCR was used to examine the expression of each 14-3-3 gene in response to salt stress and potassium and iron deficiencies in young tomato roots.
• Key Results The phylogenetic tree shows that the 14-3-3 gene family falls into two major groups in tomato plants. By using real-time RT–PCR, it was found that (a) under normal growth conditions, there were significant differences in the mRNA levels of 14-3-3 gene family members in young tomato roots and (b) 14-3-3 proteins exhibited diverse patterns of gene expression in response to salt stress and potassium and iron deficiencies in tomato roots.
• Conclusions The results suggest that (a) 14-3-3 proteins may be involved in the salt stress and potassium and iron deficiency signalling pathways in young tomato roots, (b) the expression pattern of 14-3-3 gene family members in tomato roots is not strictly related to the position of the corresponding proteins within a phylogenetic tree, (c) gene-specific expression patterns indicate that isoform-specificity may exist in the 14-3-3 gene family of tomato roots, and (d) 14-3-3 proteins (TFT7) might mediate cross-talk between the salt stress and potassium and iron-deficiency signalling pathways in tomato roots.
Key words: Solanum lycopersicum, real-time RT–PCR, expression, gene family, 14-3-3, salt stress and potassium deficiency, iron deficiency