Chitosan oligosaccharide is a low-molecular-weight product obtained by degradation of chitosan by lactate which has outstanding water-solubility and high biological activity, thus it can be easily absorbed and utilized by crops. More info:https://www.doraagri.com/product/chitosan-oligosaccharide/

1. chitosan oligosaccharide and application in Agriculture

2. What is COS and Dora-COS ?
, a short name of hitosan ligo accharide, is a
saccharide which is combined with glucosamine from two
to twenty, and is generally prepared through chemical or
enzymatic hydrolysis of chitosan.
Nf"½
/n
I n=2-20 I
Structure of COS
OH
, is produced through enzymatic degradation of
qualified chitosan using a highly active and special
enzyme-
Production of COS is technically supported by Chinese
Academy of Science, China. It is highly qualified, safety to
human, and functionally it can efficiently activate the
immunity of plants and enhance plant health.
习
”一 GlcN
02
. ""
一＾－｀刊喧＂邧"
Rx-COS
·
·
`
'
菱．一
HPLC analysis of COS
；畴3

3. What is the function of COS on plants？
1. Disease-resistant；
2. Insect-resistant;
3. Stress-resistant;
4. Promote plant growth;
5. Improve fruit quality;
6. Reduce residual organic pesticide

4. What is the mechanism of COS？
When COS is applied on plants,
COS will soon be recognized by
some specific receptors located at
plant cell membranes, which will
bring a series of defense reactions,
including production of reactive
oxygen species, phytoalexin
biosynthesis, reinforcement of
plant cell walls, and the
accumulation of pathogenesis
related (PR) proteins, to eventually
resist diseases and stress from
environment.

5. On Aug 18, 2017, Prof. Du’s plant
vaccine program was broadcasted at
CCTV-2, and obtained nationwide
attentions.
2010，Prof. Du for the first time
proposed“oligosaccharin as an efficient plant
vaccine”, and thereafter he and his team
made a monograph about plant vaccine.
Staring from 1997, with the support of several
National programs, Prof. Yuguang Du performed
series of research to understand the function and
mechanism of oligosacchrins in plant protection.
1985，Prof. Peter Albersheim, founder of CCRC, for the
first time discovered the effects of Oligosacchrins in
regulating plant growth and defense responses.
What we know about COS?
1985
1997
2011
2016
2017

6. Performance of Dora-COS on Rice
CK
Dora-COS
CK Dora-COS
CK Dora-COS
Dora-COS can stimulate rice to enhance its
ability to efficiently resist serious diseases,
including rice sheath blight, blast pathogens,
bakanase disease, and so on.
As a result, the yield increased to a level of
4.98～10.98% compared with the control.

8. Performance of Dora-COS on Chinese tea
8
1) Disease-resistant.
2) Improve quality. The content of tea polyphenols increased 5-10%;
3) Early harvest. 7-10 days earlier than normal management;
4) Reduce residual pesticide. Reduce residual organic pesticides left
on leaves, e.g. pyidaben, chlorpyrifos, fenpropathrin, bifenthrin, and
so on;
5) Increase yield.
Dora-
COS
treatment

9. Regulate the growth of tomato by Dora-COS
9Lab experiment performed in Argentina, 2017
Dora-COS increases the total amount of the extra-grade
tomato compared to the control.

10. Effect of Dora-COS on Balsam pear
CK
Dora-COS
Dora-COS can promote the
health of balsam pear and
protect it from being attacked
by diseases.
Field test performed in Hainan,
China
Application method:
Spray Dora-COS solution (50 ppm)
on leaves every 14 days

11. Effect of Dora-COS on pepper
CK
Dora-COS
Surveyed at May 31 Surveyed at Aug 21
1) Protect plants from disease
2) Increase yield
Application method:
Spray Dora-COS solution (50 ppm) on
leaves every 14 days

12. Dora-COS induces wild cabbage against whitefly
Negative Control
(water)
Positive Control
(dinotefuran)
Dora-COS（80ppm）

13. Science, 2012, 336:1160-1164
Nature, 2006, 444(16):323-329
Nature, 1985, 314(18):615-617
Critical Rev Biotechnol, 2015, 35:29-43
Carbohyd Polym, 2010, 82:1-8
Carbohyd Polym, 2009, 75(4):612-617
Carbohyd Polym, 2011, 86(2):774-82
Plant Cell Rep 2011,30: 1153-62
J. Agric.Food Chem. 2012, 60, 136−143
J Plant P, 2007, 89(1): 69-79
Carbohyd Polym, 2012, 90:491-495
Plant Phys Biochem, 2006, 44: 910–916
Carbohyd Polym, 2010, 82:136–142
PNAS, 2007, 104:19613-19618
Plant Cell, 2008, 20:471-481
Phytophathology, 2006, 96:1188-1194
References