关键词: CRISPR/Cas9, 拟南芥SWEET1/2/3, 葡萄糖敏感性, 角果发育

Abstract: SWEET (sugars will eventually be exported transporters) genes widely present in plants, animals and microorganisms, and form transmembrane channels in the cell membrane or organelle membrane to assist sugar transport across the membrane. Three Arabidopsis SWEET1/2/3 comprise the CladeⅠ subfamily of the SWEET gene family. By expression data analysis, SWEET1 was preferentially expressed in floral organs, SWEET2 was expressed in vegetative growth and reproductive growth, and SWEET3 was expressed in flowers. Although being characterized as active glucose transporters in vitro, their physiological functions were still unclear, probably because of a lack of loss-of-function mutants and functional redundancy. In this study, the targeted mutations in sweet1/2/3 were created by using the CRISPR/Cas9 system, and the sweet1、sweet1/2、sweet3和sweet1/2/3 mutants were identified. All of these mutants did not show obvious phenotypes during vegetative growth, however, interestingly, they displayed significantly shorter siliques than that of wild type (WT). Moreover, the sweet1, sweet1/2, and sweet1/2/3 mutants were more sensitive to glucose, characterized by shorter roots and severely reduced stature under, indicating that SWEET1/2/3 were indispensable components in glucose signaling. Further analysis on the critical genes in glucose signaling pathway found that HXK1, KIN10 and KIN11 did not show any difference of transcriptional and translational expression between WT and the mutants. The results suggested the Arabidopsis SWEET1/2/3 genes played important roles in glucose signaling, especially on regulating siliques development.

Key words: CRISPR/Cas9, Arabidopsis SWEET1/2/3, glucose sensitivity, silique development