Increasing starch yield using gene technology is one of the most important
research priorities and is of primary interest to scientists. Therefore,
studies on the pathway of starch synthesis and decomposition in plants in
general and for cassava in particular could contribute to promoting the goal
of improving starch yield.

In higher plants, starch synthase (SS) enzymes are encoded by five gene
groups called GBL (granule-bound starch synthase), SSI, SSII, SSIII, and
SSIV. In particular, each SS enzyme variant has different constituents and
certain roles in amylopectin synthesis. In this study, ssiv gene from the
KM140 cassava was isolated. Ssiv gene was inserted into
pK7WG2D-35S:SSIV:T35S vector. Afterward, this new vector was transformed
into tobacco plants using Agrobacterium tumefaciens. The success of
transformation was checked by PCR and evaluation of gene expression was
performed by analyzing the starch content. The results indicated that the
starch content in transgenic plants was much higher in comparison to the
control at the same growing conditions (leaves 26,9 - 67,9%, roots 6,8 -
17,6%). This research could lead to a new direction in the creation of
genetically modified crops that have the potential of increasing starch
accumulation.



[www.isaaa.org]