Over-expression of microRNA169 confers enhanced drought tolerance to tomato

Abstract

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.

Assessment of miRNA expression profile and differential expression pattern of target genes in cold-tolerant and cold-sensitive tomato cultivars

“…Similarly, miR169 was induced in response to drought stress and led to repression of the expression of three nuclear factor Y subunit genes. [52] Contrary, multi-drug resistance protein ABC transporter was highly induced in all genotypes, especially in the most cold-tolerant tomato cultivar (LA1777; 5.8 FC). Multi-drug resistance-associated proteins (MRPs or ABCCs) are involved in cellular detoxification by transporting toxic compounds from cytosol into the vacuole.…”

“…[32,52] SGN-U236908 (TIR) was repressed in all three tomato genotypes. The degradation of TIR mRNAs may subsequently prevent depression of auxin-signalling pathway.…”

MicroRNA, a new target for engineering new crop cultivars

“…16 Transgenic tomato with overexpressing miR169 significantly enhanced tomato plant tolerance to drought stress. 17 Studies shows that these miRNAs reduced the water loss by inhibiting stomatal open and increased water retention and cell membrane integrity in transgenic plants. 16,17 Overexpression of miR319 also enhanced plant tolerance to cold stress in transgenic rice evidenced by high survival rate and increasing cold acclimation.…”

“…17 Studies shows that these miRNAs reduced the water loss by inhibiting stomatal open and increased water retention and cell membrane integrity in transgenic plants. 16,17 Overexpression of miR319 also enhanced plant tolerance to cold stress in transgenic rice evidenced by high survival rate and increasing cold acclimation. 18 Transgenic plant with overexpression of miR408 enhanced plant tolerance to salinity, cold and oxidative stress, but increased sensitivity to drought and osmotic stress in Arabidopsis.…”

Plant exomics: Concepts, applications and methodologies in crop improvement

“…106 MiRNA169 regulates NSR (nitrogen starvation response) and N starvation causes their down regulation in both shoots and roots. 107 Overexpression of miR 169 in transgenic Arabidopsis plants causes less N accumulation and more sensitization to stress 107 , and increases drought tolerance in transgenic tomatoes 108 thus plays an important role in physiological processes and WES is unable to provide such information as these miRNAs are coded most of the time by introns. 6 Similarly, untranslated regions have been reported to play major role in localization, functioning and stability regulation.…”