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Updated: Feb 18, 2026

An Induction System for Clustered Stomata by Sugar Solution Immersion Treatment in Arabidopsis thaliana Seedlings
Published on: February 15, 2019
Regulation of Sucrose Transporters and Phloem Loading in Response to Environmental Cues
Qiyu Xu1,2, Siyuan Chen1, Ren Yunjuan1,2
1College of Life Science, Northwest A&F University, 712100 Yangling, China.
Abstract:
Suc transporters (SUTs) play a key role in the allocation and partitioning of photosynthetically fixed carbon in plants. While a function could be assigned to many members of the SUT family, almost no information is available on their regulation. Here, the transcriptional regulation of SUTs in response to various environmental stimuli in the leaves of five dicots (Arabidopsis [Arabidopsis thaliana], soybean [Glycine max], potato [Solanum tuberosum], tomato [Solanumlycopersicum], and poplar [Populus spp.]) and four monocots (maize [Zeamays], rice [Oryza sativa], wheat [Triticum aestivum], and barley [Hordeum vulgare]) was investigated. Extensive data on expression of SUTs in relation to changes of environmental conditions were obtained through a global analysis of 168 transcriptomics data sets. Results were validated by quantitative PCR measurements and extended by the measurement of photosynthesis rate and phloem sugar content to draw insight on the correlation of SUT expression and sugar export from leaves. For the apoplasmic phloem loaders, a clear difference in transcriptional regulation in response to different environmental stimuli was observed. The consistent patterns of SUT expression under abiotic stress indicates which types of SUTs are involved in the regulation of leaf sugar status and in stress signaling. Furthermore, it is shown that down-regulation of phloem loading is likely to be caused by transcriptional regulation of SUTs, while up-regulation depends on post-transcriptional regulation. In poplar, expression of PtaSUT4 was found to consistently respond to environmental stimuli, suggesting a significant role in the regulation of sugar export from leaves in this passive symplasmic phloem loader.
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Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
Transcellular Transport of Solutes
Secondary Active Transport
Secondary Active Transport

