Sucrose phosphate synthase expression influences poplar phenology

Abstract

The objective of this study was to manipulate the intracellular pools of sucrose, and investigate its role in regulating plant growth, phenology (leaf senescence and bud break) and fibre development. This objective was achieved by differentially expressing an Arabidopsis (Arabidopsis thaliana L. Heynh.) sucrose phosphate synthase (SPS) gene in hybrid poplar (Populus alba L.xPopulus grandidentata Michx.), a model system for tree biology with substantial industrial relevance in the context of short rotation forestry and a target bioenergy crop. Phenotypic differences were evident in the transgenic trees, as both the timing of bud flush and leaf senescence were altered compared to wild-type (WT) trees. Tree height and stem diameter were similar in WT and in the AtSPS transgenic trees, however, there were differences in the length of xylem fibres. Elevated concentrations of intracellular sucrose in both leaf and stem tissue of the transgenic trees are associated with a prolonged onset of senescence and an advancement in bud flush in the following spring. The association among sucrose content, tree phenology and elevated SPS gene expression implicates both enzyme and product in regulating poplar developmental processes.

Impact of concurrent overexpression of cytosolic glutamine synthetase (GS1) and sucrose phosphate synthase (SPS) on growth and development in transgenic tobacco

“…The pods in the SPS over-expressers have significantly higher biomass individually and as a collection per plant followed by the co-expressers. There are several reports on the association of increased SPS activity with the production of new sinks and increased sink strength, although the sinks may range from flowers, fruits, tubers, fiber, stem and more (Micallef et al 1995;Park et al 2008Park et al , 2009Haigler et al 2007;Nguyen-Quoc et al 1999;Baxter et al 2003;Ishimaru et al 2008;Laporte et al 1997Laporte et al , 2001). An increase in pod size and overall pod weight per plant showed an inverse correlation with vegetative growth and height, in that the SPS transformants with its biggest pods and overall highest pod weight per plant, has the shortest stature compared to all the other classes of transformants.…”

“…Suc plays a crucial role in the functioning of different processes, which are key to plant growth (Galtier et al 1995;Grof et al 2007;Ishimaru et al 2004). There are several reports on the overexpression of SPS using transgenic approaches (Coleman et al 2010;Haigler et al 2007;Nguyen-Quoc and Foyer 2001;Tian et al 2010;Zuñiga-Feest et al 2005) with varied consequences, but in general, increased SPS activity is associated with the production of new sinks and increased sink strength, although the sinks may range from flowers, fruits, tubers, fiber, stem and more (Micallef et al 1995;Park et al 2008Park et al , 2009Haigler et al 2007;NguyenQuoc et al 1999;Baxter et al 2003;Ishimaru et al 2008;Laporte et al 2001).…”

Elevated temperature and CO2 stimulate late season photosynthesis but impair cold hardening in pine

“…Leafsoluble carbohydrates were extracted according to Park et al (2009). Two hundred fifty micrograms galactitol internal standard was added to 30 to 40 mg homogenized, lyophilized needle tissue.…”

“…Leaf starch was determined using the residual tissue pellet from the soluble sugar extraction according to Park et al (2009). The pellet was dried overnight at 55°C.…”

Cloning and sequence analysis of sucrose phosphate synthase gene from varieties of Pennisetum species

“…SPS is a key enzyme for sucrose synthesis in higher plants. As such, sucrose accumulation is positively correlated with SPS activity (Zhao et al, 2001;Park et al, 2009), and plants with relatively high sugar content such as sugar beet and sugarcane have been shown to have high SPS activity (Li et al, 2010;Ye et al, 2011). The SPS gene family has subfamilies A-C (Langenkämper et al, 2002;Zhou et al, 2006;Huang et al, 2012).…”