Overexpression of a Grapevine Sucrose Transporter (VvSUC27) in Tobacco Improves Plant Growth Rate in the Presence of Sucrose In vitro

Abstract

The import of sugar from source leaves and it further accumulation in grape berries are considerably high during ripening, and this process is mediated via sucrose transporters. In this study, a grape sucrose transporter (SUT) gene, VvSUC27, located at the plasma membrane, was transferred to tobacco (Nicotiana tabacum). The transformants were more sensitive to sucrose and showed more rapid development, especially roots, when cultured on MS agar medium containing sucrose, considering that the shoot/root dry weight ratio was only half that of the control. Moreover, all transformed plants exhibited light-colored leaves throughout their development, which indicated chlorosis and an associated reduction in photosynthesis. The total sugar content in the roots and stems of transformants was higher than that in control plants. No significant difference was observed in the leaves between the transformants and control plants. The levels of growth-promoting hormones were increased, and those of stress-mediating hormones were reduced in transgenic tobacco plants. The qRT-PCR analysis revealed that the expression of VvSUC27 was 1,000 times higher than that of the autologous tobacco sucrose transporter, which suggested that the markedly increased growth rate of transformants was because of the heterogeneously expressed gene. The transgenic tobacco plants showed resistance to abiotic stresses. Strikingly, the overexpression of VvSUC27 leaded to the up regulation of most reactive oxygen species scavengers and abscisic acid-related genes that might enable transgenic plants to overcome abiotic stress. Taken together, these results revealed an important role of VvSUC27 in plant growth and response to abiotic stresses, especially in the presence of sucrose in vitro.

Expression of Sucrose Transporters from Vitis vinifera Confer High Yield and Enhances Drought Resistance in Arabidopsis

“…The exterior of VvSUC27-OE seeds was shorter and narrower than WT seeds, which resulted in a smaller seed area and embryo (Figure 1). We also observed the inhibition of germination on high sucrose-supplemented media compared with that of WT (Figure 1), consistent with the findings of a previous report [27]. Our results indicate that VvSUC27 has a strong sucrose transport ability that may hardly be regulated by AtSUTs or NtSUTs expressed in the seeds.…”

“…In a previous study, we determined that VvSUC27 is a plasma membrane protein [27]. Besides, VvSUC27 was expressed in Nicotiana tabacum to produce transformants that were sensitive to sucrose and had rapid organ development, especially in roots, when cultured on sucrose-supplemented medium [27]. In this study, VvSUC27 was overexpressed in transgenic Arabidopsis to compare its function with that of the VvSUC11and VvSUC12-OE lines.…”

“…VvSUC27 is similar and belongs to the specific high-affinity SUT1 clade in dicots ( Figure S1). In a previous study, we determined that VvSUC27 is a plasma membrane protein [27]. Besides, VvSUC27 was expressed in Nicotiana tabacum to produce transformants that were sensitive to sucrose and had rapid organ development, especially in roots, when cultured on sucrose-supplemented medium [27].…”

“…As a member of the SUT1 subfamily, VvSUC27 has been described as a low-affinity/high-capacity SUT, VvSUC11 has been characterized as a member of the traditional low-affinity SUT4 subfamily, while VvSUC12 belongs to the SUT2/SUC3 subfamily [23][24][25][26]. Previously, we have elucidated that VvSUC27 is located on the plasma membrane and negatively correlated with sugar accumulation, which indicates its important role in plant development [27]. In this study, the functions of SUTs were further systematically evaluated using transgenic Arabidopsis thaliana lines.…”

Expression profiling of two sucrose transporter genes during post-anthesis in wheat

“…SUTs function as sucrose / proton symporters that use the energy stored in the proton gradient across the membrane generated by H + -ATPases to drive sucrose movement (Braun et al, 2014). SUTs also have the main role in plant resistance under abnormal conditions by carbohydrate distribution; facilitate the production of secondary metabolites and ROS scavenging (Cai et al, 2017;Rezaul et al, 2019). Genes encoding plant SUTs have been isolated from different plants, such as rice (Eom et al, 2011), wheat (Deol et al, 2013), sorghum (Milne et al, 2013) and Saccharum species (Zhang et al, 2016), and are known to form small gene families.…”