Effect of nano-silicon application on the expression of salt tolerance genes in germinating tomato (Solanum lycopersicum L.) seedlings under salt stress

Nowadays, nano-silicon (N-Si) has been used to enhance seed germination, plant growth, and improvement of photosynthetic quantum under environmental stresses. In this study, we examined the effects of different doses of N-Si on the salt tolerance of tomato (Solanum lycopersicum L.) plants during germination. The tomato seeds were treated with different doses of N-Si and were germinated under salt stress. The seed germination and seedling growth of tomato plants were significantly inhibited by salt stress. However, this inhibition was alleviated by the exposure to N-Si. The germination percentage and germination rate of tomato seeds and the root length and fresh weight of tomato seedlings were increased after exposure to N-Si under NaCl stress. The expression profiles of salt stress genes were investigated with the semi-quantitative RT-PCR. Of the fourteen investigated salt stress genes, four genes, AREB, TAS14, NCED3 and CRK1, were upregulated, and six genes, RBOH1, APX2, MAPK2, ERF5, MAPK3 and DDF2, were downregulated with exposure to N-Si under salt stress. The gene expression patterns associated with exposure to N-Si suggested a potential involvement of N-Si in the plant's response to stress, an indication that N-Si might be useful to improve plants' tolerance of salinity.