Downregulation of SL-ZH13 transcription factor gene expression decreases drought tolerance of tomato

摘要

Zinc finger-homeodomain proteins(ZF-HDs) are transcription factors that regulate plant growth,development,and abiotic stress tolerance.The SL-ZH13 gene was found to be significantly upregulated under drought stress treatment in tomato(Solanum lycopersicum) leaves in our previous study.In this study,to further understand the role that the SL-ZH13 gene plays in the response of tomato plants to drought stress,the virus-induced gene silencing(VIGS) method was applied to downregulate SL-ZH13 expression in tomato plants,and these plants were treated with drought stress to analyze the changes in drought tolerance.The SL-ZH13 silencing efficiency was confirmed by quantitative real-time PCR(qRT-PCR) analysis.In SL-ZH13-silenced plants,the stems wilted faster,leaf shrinkage was more severe than in control plants under the same drought stress treatment conditions,and the mean stem bending angle of SL-ZH13-silenced plants was smaller than that of control plants.Physiological analyses showed that the activity of superoxide dismutase(SOD) and peroxidase(POD) and the content of proline(Pro) in SL-ZH13-silenced plants were lower than those in control plants after 1.5 and 3 h of drought stress treatment.The malondialdehyde(MDA) content in SL-ZH13-silenced plants was higher than that in control plants after 1.5 and 3 h of drought stress treatment,and H2O2 and O2^-· accumulated much more in the leaves of SL-ZH13-silenced plants than in the leaves of control plants.These results suggested that silencing the SL-ZH13 gene affected the response of tomato plants to drought stress and decreased the drought tolerance of tomato plants.