Biomedical Engineering Reference
In-Depth Information
5.3.2
Oligosaccharins
Oligosaccharins are a class of active molecules that show physiological regula-
tion functions. They mainly refer to the degradation products of natural ligno-
cellulosic materials and chitin, which contain bioactive oligosaccharide chains
such as xyloglucan oligosaccharide, pectin oligosaccharide,
“
-xylan oligosaccha-
rides, fungal
-dextran oligosaccharides, chitin oligosaccharides, some glycopro-
tein oligosaccharide chains, and oligosaccharide peptides. A small amount of
oligosaccharides can stimulate a strong disease-resistant response in plant cells
and generate and accumulate disease-resistant substances, such as phytoalexin,
phenylalanine ammonia lyase, chitinase, and lignin [
59
]. Recent studies found that
the oligosaccharins not only can stimulate a variety of defense reaction systems,
including phytoalexin synthesis, but also can effectively regulate plant growth and
developmental processes.
Microbial diseases are crucial causes of crop failures because of the wide range
of plant pathogens and mutations. Chemical pesticides, although quick and efficient,
always lead to a variety of side effects if they are applied for long term and without
limitation. Actually, the plant has a natural resistance to some microbial infection
and can start self-defense in response to a pathogen attack after microbial infection.
Studies have shown that this self-defense capability can be induced by exogenous
oligosaccharins, and the use of oligosaccharins as biological pesticides not only can
simplify disease prevention and control measures but also can replace the use of
chemical pesticides to reduce drug residues and environmental damage [
60
].
In the early 1980s, it was found that oligosaccharins involved in plant growth and
development, as signaling molecules participating in the regulation of plant growth
and development, such as cell division, differentiation, formation of new organs, and
embryogenesis. Tran Thanl Van et al. also proposed that some plant morphogenesis
regulatory factors, such as pH and ionic concentration, play a regulatory role by
activation of specific hydrolases on the cell wall to release oligosaccharins [
61
].
Much research into oligosaccharide application in agricultural practice has
been performed. Yu et al. [
62
] studied the effect of amino oligosaccharin on the
prevention and control of tobacco virus disease; the results showed that amino
oligosaccharides could effectively promote the growth and development of tobacco
plants and showed a significant role in the prevention and control of tobacco
virus diseases. In particular for cucumber mosaic virus, the control efficiency
of indoor inoculation was up to 34.92 %. Biochemical parameters revealed that
spraying the amino oligosaccharin and inoculating virus can effectively promote
the accumulation of proline in the tobacco plant, reduce the alondialdehyde content
in the plant, and adjust resistance to external stress. The studies from Mei et al. [
63
]
showed that pectin oligosaccharides could promote the growth of callus of
Euptelea
pleiospermum
, argotaenia, and rice and affect suspension cell growth of
Berberis
vulgaris
and jatrorrhizine biosynthesis. Liu et al. [
64
] studied the physiological
effect of chitosan on wheat seeds; the results showed that chitosan could promote
the beginning of the wheat seed embryo cell cycle and increase the number of
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