Background: The family of NAC proteins (NAM, ATAF1/2, and CUC2) represent a class of large plant-specific transcription factors. However, identification and functional surveys of NAC genes of tomato (Solanum lycopersicum) remain unstudied, despite the tomato genome being decoded for several years. This study aims to identify the NAC gene family and investigate their potential roles in responding to Al stress. Results: Ninety-three NAC genes were identified and named in accordance with their chromosome location. Phylogenetic analysis found SlNACs are broadly distributed in 5 groups. Gene expression analysis showed that SlNACs had different expression levels in various tissues and at different fruit development stages. Cycloheximide treatment and qRT-PCR analysis indicated that SlNACs may aid regulation of tomato in response to Al stress, 19 of which were significantly up- or down-regulated in roots of tomato following Al stress. Conclusion: This work establishes a knowledge base for further studies on biological functions of SlNACs in tomato and will aid in improving agricultural traits of tomato in the future.

Aluminum (Al) is the most abundant metal element in the earth’s crust. On acid soils, at pH 5.5 or lower, part of insoluble Al-containing minerals become solubilized into soil solution, with...

Significant secretion of citrate from root apex of rice bean (Vigna umbellata) is delayed by several hours under aluminium ( Al ) stress. However, the molecular basis of regulation of VuMATE1, a gene encoding an Al ‐activated citrate transporter, remains unclear. In this study, we used suppression subtractive hybridization together with reverse northern blot analysis and qRT‐PCR to identify genes with altered transcript levels in the root apex after treatment with low (5 μm) or high (25 μm) concentration of AlCl₃ for a short time (4 h). We found that in addition to VuMATE1, 393 genes showed an early response to Al . Among functionally annotated genes, those related to ‘metabolism and energy’, ‘signal transduction and transcription’ and ‘transport’ was predominantly up‐regulated, whereas those associated with ‘protein translation, processing and degradation’ was predominantly down‐regulated. Comparative analysis of transcriptional profiles highlighted candidate genes associated with citrate secretion and revealed several new aspects of the molecular processes underlying Al toxicity and tolerance. Based on the data, it is proposed that metabolic changes represent adaptive mechanisms to Al stress, whereas inhibition of both cell elongation and cell division underlies Al ‐induced root growth inhibition.