TY - JOUR
AU - Myers, Alan
AB - Background: The biochemical mechanisms that determine the molecular architecture of amylopectin are central in plant biology because they allow long-term storage of reduced carbon. Amylopectin structure imparts the ability to form semi-crystalline starch granules, which in turn provides its glucose storage function. The enzymatic steps of amylopectin biosynthesis resemble those of the soluble polymer glycogen, however, the reasons for amylopectin's architectural distinctions are not clearly understood. The multiplicity of starch biosynthetic enzymes conserved in plants likely is involved. For example, amylopectin chain elongation in plants involves five conserved classes of starch synthase (SS), whereas glycogen biosynthesis typically requires only one class of glycogen synthase. Results: Null mutations were characterized in AtSS2, which codes for SSII, and mutant lines were compared to lines lacking SSIII and to an Atss2, Atss3 double mutant. Loss of SSII did not affect growth rate or starch quantity, but caused increased amylose/amylopectin ratio, increased total amylose, and deficiency in amylopectin chains with degree of polymerization (DP) 12 to DP28. In contrast, loss of both SSII and SSIII caused slower plant growth and dramatically reduced starch content. Extreme deficiency in DP12 to DP28 chains occurred in the double mutant, far more severe than the summed changes 
TI - Overlapping functions of the starch synthases SSII and SSIII in amylopectin biosynthesis in Arabidopsis
JF - BMC Plant Biology
DO - 10.1186/1471-2229-8-96
DA - 2008-09-23
UR - https://www.deepdyve.com/lp/springer-journals/overlapping-functions-of-the-starch-synthases-ssii-and-ssiii-in-7CvueGygcz
SP - 1
EP - 18
VL - 8
IS - 1
DP - DeepDyve
ER -