Over-expression of microRNA169 confers enhanced drought tolerance to tomato

• DOI: 10.1007/s10529-010-0436-0
• Publication Date: 2010-10-19T05:52:45Z
• Authors: Xiaohui Zhang; Zhe Zou; Pengjuan Gong; Junhong Zhang; Khurram Ziaf; Hanxia Li; Fangming Xiao; Zhibiao Ye
• Keywords: 0301 basic medicine; 2. Zero hunger; Gene Expression; 15. Life on land; Plants, Genetically Modified; 6. Clean water; Droughts; MicroRNAs; 03 medical and health sciences; Solanum lycopersicum; Stress, Physiological; Plant Stomata; Acholeplasmataceae

Plant miRNA regulates multiple developmental and physiological processes, including drought responses. We found that the accumulation of Sly-miR169 in tomato (Solanum lycopersicum) was induced by drought stress. Consequently, Sly-miR169 targets, namely, three nuclear factor Y subunit genes (SlNF-YA1/2/3) and one multidrug resistance-associated protein gene (SlMRP1), were significantly down-regulated by drought stress. Constitutive over-expression of a miR169 family member, Sly-miR169c, in tomato plant can efficiently down-regulate the transcripts of the target genes. Compared with non-transgenic plants, transgenic plants over-expressing Sly-miR169c displayed reduced stomatal opening, decreased transpiration rate, lowered leaf water loss, and enhanced drought tolerance. Our study is the first to provide evidence that the Sly-miR169c negatively regulates stomatal movement in tomato drought responses.