the slides contain information about herbicides, weeds, and herbicide resistance plant it mode of action how it can be created and how it is found

2.  Herbicide resistance is ”the inherited ability of an
individual plant to survive a herbicide application that
would kill a normal population of the same species.”
 Weeds are unwanted and useless plants that grow
along side crops.
 Weeds compete with crops for nutrients and light so as
a result they are responsible for crops annual yield of
about 10-150%.
 To tackle this modern agriculture has introduced
herbicides which are a broad spectrum.

3. An ideal herbicides should posses the following
characters.
 Capable of killing the weeds without affecting the
plants.
 Non toxic to animals and micro organism.
 Easily degradable in soil.
 Environment friendly.
but
 the commercial available herbicides can not
discriminate weed from crops so can affects the crops
too.
 As crops are affected by herbicides so we need to
engineered herbicide resistance plants.

5. A number of biological manipulation involved in genetic engineering
are in use to develop herbicide resistance plants.
1. Over expression of EPSPS gene.
2. Use of mutant EPSPS gene.
3. Detoxification of herbicide by a foreign gene.

6.  An over expression was detected in a flowering
plant “Petunias", from which the gene was
isolated and introduced in other plants.
 The resulting transgenic plant can tolerate
glyphosate 2-4 times higher than that to kill
weed.

7.  EPSPS mutant gene resistant to
glyphosate was first found in
s.typhimurium, it was found out
that a single base substitution
(C-T) changes A. acid proline to
serine
 Thus enzyme can not bind to
glyphosate .

8.  The soil micro organism posses an enzyme glyphosphate oxidase
which convert glyphosate into glyoxylate.
 The gene was isolated from “ochrobactrum anthropi” and
introduced into crops.