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Molecular Pathogens 2012, Vol.3, No.4, 19
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Review and Progress Open Access
Genetic Pathways of Disease Resistance and Plants-Pathogens Interactions
Siddra Ijaz , Azeem Iqbal khan ,
Centre of Agricultural Bioche mistry and Biotechnology (CABB), University of Agriculture Faisalabad, Pakistan
Corresponding author email: siddraijazkhan@yahoo.com;
Authors
Molecular Pathogens, 2012, Vol.3, No.4 doi: 10.5376/mp.2012.03.0004
Received: 06 Sep., 2012
Accepted: 14 Sep., 2012
Published: 05 Nov., 2012
Copyright
: © 2012 Siddra I.This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Ijaz S. and Khan A.I., 2012, Genetic Pathways of Disease Resistance and Plants-Pathogens Interactions, Molecular Pathogens, Vol.3, No.4 19-26 (doi:
10.5376/mp.2012.03.0004)
Abstract
Resistance breeding is comparatively less effective, tedious and unremitting process because the pathogens keep on
mutating and generate new races. The developed material fell susceptible to these newly evolved races. Even then the breeders are
triumphant in shielding most of the crops under cultivation around the globe from fungal diseases. This review summarizes the
knowledge about genetic pathways involved in plant disease resistance mechanism, plant-pathogen interaction, production of
phytoalexins/secondary metabolites and other pathogenesis related proteins and their interactions in plant defense response.
Keywords
Resistance breeding; Plant-pathogen interaction; Disease resistance
Introduction
Gigantic advancements, in understanding the extremely
complex molecular events occurring in plant-pathogen
interactions, have been made. This information has
provided a number of opportunities and strategies
which can be employed to develop transgenic
plants resistant to pathogens. The utilization of
agrochemicals creates many perils that include
detrimental effects on the ecosystem and a raise in the
input cost of the farmers.
Over and over again sexual crosses are intricate to
build genetic exchange in the hybrids and are skimpy
due to low incidence of pairing between chromosomes
of crop species and wild species. Tribulations can also
happen due to linkage drag (gene/s for resistance are
linked to some deleterious genes which lower the
yield of the crop variety). Genetic variability is a
basically a product of genetic recombination, mutation
and natural selection, so the disparity in genetic
background is arbitrated by these factors (Ijaz
et al.,
2012).
A lot of work has been done to identify the genes
which can introduce into the plants so that they may
build or enhance their resistance to fungal pathogens.
Similarly many genes have been identified and cloned
from plants those play role in identifying and tackling
the pathogens (Feys and Parker, 2000; Takken and
Joosten, 2000). Various signaling pathways tracking
the pathogen infectivity have been scrutinized and
numerous antifungal compounds have been
recognized and produced by plants to fight fungal
infections. Interactions of plant pathogenic fungi with
their hosts are a complex phenomenon which involve
many mechanisms like the synthesis of fungal toxins
and enzymes that degrade the plant cell wall
(Rodriguez and Redman, 1997). Major polymers of
plant cell wall are degraded by the action of various
enzymes; those are secreted from fungal pathogens and
these principal enzymes are cutinases, pectate-lyases
and endopolygalacturonases.
Plant apply countless strategies inhibit the ingress of
pathogen into cell wall. One of such strategies is
reinforcement of cell wall which involve the phenolic
compounds production such as lignin is accumulated
in the cell wall and extra cellular matrix is
strengthened by glycoproteins rich in hydroxyproline
and others similarly the cell wall breakage result in
the release of small oligomers which act as elicitors
for initiating the plant defense responses (Wegener et
al., 1996). The enzymes secreted by fungal pathogens
to degrade the plant cell wall are also inhibited by plant