title: The Plasma Membrane-Localized Sucrose Transporter IbSWEET10 Contributes to the Resistance of Sweet Potato toFusarium oxysporum.
abstract: SWEET (Sugars Will Eventually be Exported Transporter) proteins, a novel family of sugar transporters, mediate the diffusion of sugars across cell membranes and acts as key players in sucrose phloem loading. Manipulation of SWEET genes in plants leads to various effects on resistance to biotic and abiotic stresses due to disruption of sugar efflux and changes in sugar distribution. In this study, a member of the SWEET gene family,IbSWEET10, was cloned from the sweet potato line ND98. mRNA expression analysis in sweet potato and promoter β-Glucuronidase analysis inArabidopsisshowed thatIbSWEET10is highly expressed in leaves, especially in vascular tissue. Transient expression in tobacco epidermal cells revealed plasma membrane localization of IbSWEET10, and heterologous expression assays in yeast indicated thatIbSWEET10encodes a sucrose transporter. The expression level ofIbSWEET10was significantly up-regulated in sweet potato infected withFusarium oxysporumSchlecht. f. sp.batatas.Further characterization revealedIbSWEET10-overexpressing sweet potato lines to be more resistant toF. oxysporum, exhibiting better growth after infection compared with the control; conversely, RNA interference (RNAi) lines showed the opposite results. Additionally, the sugar content ofIbSWEET10-overexpression sweet potato was significantly reduced, whereas that in RNAi plants was significantly increased compared with the control. Therefore, we suggest that the reduction in sugar content caused byIbSWEET10overexpression is the major reason for the enhancedF. oxysporumresistance of the transgenic plants. This is the first report that the IbSWEET10 transporter contributes to the resistance of sweet potato toF. oxysporum. TheIbSWEET10gene has the great potential to be used for improving the resistance toF. oxysporumin sweet potato and other plants.
authors.affiliation: Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University Beijing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University Beijing, China.
authors.forename: Yannan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University Beijing, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University Beijing, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University Beijing, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhai
authors.affiliation: Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University Beijing, China.
authors.forename: Qingchang
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University Beijing, China.
authors.forename: Shaozhen
authors.initials: S
authors.lastname: He
keywords: Fusarium oxysporum; IbSWEET10; plasma membrane; sucrose transporter; sweet potato