Suppression of cucumber stachyose synthase gene CsSTS inhibits phloem loading and reduces low temperature stress toleranceReportar como inadecuado

Suppression of cucumber stachyose synthase gene CsSTS inhibits phloem loading and reduces low temperature stress tolerance - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Plant Molecular Biology

pp 1–15

First Online: 12 June 2017Received: 24 August 2016Accepted: 02 June 2017DOI: 10.1007-s11103-017-0621-9

Cite this article as: Lü, J., Sui, X., Ma, S. et al. Plant Mol Biol 2017. doi:10.1007-s11103-017-0621-9


Stachyose is the main transporting sugar in phloem of Raffinose family oligosaccharides-transporting species. Stachyose synthase STS is a key enzyme for stachyose biosynthesis, but the gene encoding STS is poorly characterized in cucumber Cucumis sativus L., which is a model plant for studying stachyose metabolism and phloem function. In this research, stachyose synthase gene CsSTS from cucumber was isolated and its physiological functions were analyzed. CsSTS expressed mainly in the phloem of the minor veins in mature leaves and localized to companion cells. Reverse genetics with CsSTS RNAi lines revealed obviously reductions in STS activity and stachyose content along with a small amount of starch accumulation in leaves, suggesting that CsSTS is involved in phloem loading of cucumber leaves. After 6 °C low temperature stress, malondialdehyde content and electrical conductivity increased, especially in CsSTS-RNAi plants. But CsSTS expression was up-regulated, STS activity and stachyose level increased, the activities of reactive-oxygen-scavenging enzyme in cucumber seedlings improved significantly and starch accumulation reduced, especially in CsSTS-OE lines. These results demonstrate clearly that CsSTS is involved in phloem loading, carbohydrate distribution and tolerance of cucumber seedlings to low temperature stress.

KeywordsCucumber Low temperature stress Phloem Stachyose Stachyose synthase Jianguo Lü and Xiaolei Sui have contributed equally to this work.

Electronic supplementary materialThe online version of this article doi:10.1007-s11103-017-0621-9 contains supplementary material, which is available to authorized users.

Autor: Jianguo Lü - Xiaolei Sui - Si Ma - Xin Li - Huan Liu - Zhenxian Zhang


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