摘要

Adverse environmental conditions, such as drought, high salinity and extreme temperature, severely affect the growth and productivity of crop plants. MADS-box transcription factors have been described to participate in stress responses. In our study, a MADS-box transcription factor gene, SlMBP8, has been cloned from tomato. The expression of SlMBP8 was induced by Methyl-jasmonic acid (MeJA), high salinity, high temperature, wounding and dehydration. Whereas, the transcript of SlMBP8 was down-regulated by Abscisic acid (ABA), 1-aminocyclopropane-1-carboxylic acid (ACC) and Indole-3-acetic acid (IAA). To further elucidate the function of SlMBP8 gene in response to abiotic stress, plants by knockdown of SlMBP8 through RNA interference (RNAi) were used for investigating the effect of drought and salt stresses on tomato seedlings of wild type (WT) and SlMBP8-RNAi lines. Seedling growth of SlMBP8-RNAi plants was less inhibited by salt than WT at post-germination stage. Transgenic plants became more tolerant to drought and salt stress than WT plants in soil, which was demonstrated by higher levels of chlorophyll and water contents, lower water loss rate and malondialdehyde (MDA) contents. In addition, the expression of multiple stresses related genes were significantly up-regulated in the RNAi lines under control and abiotic stresses. Taken together, these results suggest that SlMBP8 function as a negative stress-responsive transcription factor in the drought and high salinity stress signaling pathways, and may have promising applications in the engineering of drought- and salt-tolerant tomato.