Sucrose phosphate synthase and sucrose synthase activity during maturation of internodal tissue in sugarcane

Abstract

Sucrose accumulation rates, sucrose-phosphate synthase (SPS, EC 2.4.1.14) and soluble sucrose synthase (SuSy, EC 2.4.1.13) activities were measured in internodal tissue from a sugarcane (Saccharum species hybrids) variety N19. The sucrose accumulation rate sharply increases between internodes 3 to 11. In the older internodes SPS activity was at least three times higher than the SuSy activity. A highly significant positive correlation was found between SPS activity and sucrose content. In contrast, no significant correlation was observed between SuSy and sucrose content. In agreement, when radiolabelled glucose was fed to internodes with a high sucrose accumulation rate, label was equally distributed in the hexose moieties of sucrose. This clearly indicates that SPS is the major sucrose synthesis activity in the culm of sugarcane. Different kinetic forms of SPS apparently exist in the internodal tissue at different stages of development.

Sucrose synthase molecular marker associated with sugar content in elite sugarcane progeny

“…However, results from other authors (Zhu et al, 1997;Botha, 2000) indicate no correlation between sucrose synthase activity and sucrose accumulation. These contrasting results could be due to an effect of genotypic differences between different varieties.…”

Changes in the sugar content of sweet sorghum stems under natural conditions during winter in saline soil of the Yellow River Delta

“…A lack of correlation of SPS and sucrose accumulation had been reported earlier in sweet sorghum (Zhu et al, 1997), while a positive correlation between SPS activity and sucrose accumulation was reported in sugarcane stems, the evidence suggests that SPS may play a more important role in sucrose synthesis and accumulation (Botha and Black, 2000) and Botha & Black (2000) found that SPS activity is higher in mature internodes than in immature internodes. SS can also be involved in sucrose synthesis, but the equilibrium is usually in the direction of degradation.…”

“…Sucrose synthase is known to play a role in sucrose synthes is using uridine diphosphate (UDP)-glucose and fructose as substrates, but the degradation reaction dominates in vivo (Geigenberger andStitt, 1993, Botha andBlack, 2000). A lack of correlation of SPS and sucrose accumulation had been reported earlier in sweet sorghum (Zhu et al, 1997), while a positive correlation between SPS activity and sucrose accumulation was reported in sugarcane stems, the evidence suggests that SPS may play a more important role in sucrose synthesis and accumulation (Botha and Black, 2000) and Botha & Black (2000) found that SPS activity is higher in mature internodes than in immature internodes.…”

Characterization of sugar metabolism in the stem of Tachisuzuka, a whole-crop silage rice cultivar with high sugar content in the stem

“…and sweet sorghum (Sorghum bicolor), which mainly accumulate soluble sugars in the stem (for reviews, see Bihmidine et al, 2013;Slewinski, 2012;Wang et al, 2013). Those studies identified key enzymes and transporters for sugar accumulation, such as sucrose-phosphate synthase (Botha & Black, 2000;Grof et al, 2007;Liu et al, 2013;Zhu et al, 1997), vacuolar acid invertase (Liu et al, 2013;McKinley et al, 2016;Zhu et al, 1997), and tonoplast sugar transporter (Bihmidine et al, 2016). However, sugar metabolism in rice stems has received less attention.…”