Analysis of Sugar Content and Expression of Sucrose Transporter Genes (<i>OsSUTs</i>) in Rice Tissues in Response to a Chilling Temperature

Abstract

Changes in sucrose metabolism have been implicated in tissue damage found in rice plants exposed to cold. However, little is known about the effect of low temperature on sucrose transport in cold-sensitive plants such as rice. Here, we investigated the changes induced by a 12°C chilling treatment on the soluble sugar content relative to the expression of sucrose transporter genes (OsSUT1-5) in various tissues of young (6-week-old) and mature (booting stage) rice plants. Sucrose levels increased in source tissues but decreased in young panicles during the chilling treatment. Sucrose transporter genes also responded to the chilling treatment: OsSUT1 in leaf sheaths and OsSUT2 and OsSUT4 in panicles were down-regulated. Our results suggested that the sucrose translocation supported by OsSUTs in rice plants decreased during chilling treatment, assuming the involvement of OsSUT1 and OsSUT4 in phloem loading of sucrose. These changes may induce a sugar imbalance in anthers, resulting in impaired pollen development.

Plasmodesmata play pivotal role in sucrose supply to Meloidogyne graminicola‐caused giant cells in rice

“…Meanwhile, OsSUT2 was down‐regulated in rice roots during Mg parasitism, and OsSUT3 and OsSUT5 had very low RNA levels, which was also found by Takahashi et al. (2017) for aerial tissues. Only OsSUT1 and OsSUT4 have similarly high transcript levels in both noninoculated and infected rice roots at later parasitism stages.…”

Regulation of rice sucrose transporter 4 gene expression in response to insect herbivore chewing

“…Moreover, the regulation of OsSUT4 expression in spikelet tissues was developmental stage dependent (Chung et al 2014). Expression levels of OsSUT3 and OsSUT5 were quite low compared to those of OsSUT1, 2 and 4 in leaf tissues (Takahashi et al 2017).…”

Rice SUT and SWEET Transporters

“…High temperature or heat stress during the seed-filling stage reduced OsSUT1 and starch synthesis-related gene expression and led to earlier ripening and chalky grain [ 31 , 33 , 56 ]. On the other hand, low temperature or chilling treatment also downregulated the expressions of OsSUT1 , OsSUT2 , and OsSUT4 [ 50 , 57 ]. In addition, the expression of OsSUT1 was reduced in the leaf and grain but increased in the stem under submergence at the ripening stage of rice development [ 58 ].…”