Agriculture Reference
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P.rapae -induced expression of VSP1 , a marker defense gene during plant-herbivore
interaction (Vos et al. 2013 ). These studies implied that ABA may play important
roles in herbivore defense. Further studies demonstrated that the ABA-mediated
defense response against herbivore attack is tightly interconnected with the JA path-
way and that the modulation of ABA synthesis or signaling in response to herbivore
attack can modulate JA-driven defense responses. For example, during plant-herbi-
vore interactions, ABA and JA can synergistically regulate the transcription of the
MYC2 transcription factor, which is activated upon feeding by herbivorous insects
and finally regulated the expression of downstream marker genes, such as VSP1
and VSP2 (Anderson et al. 2004 ; Thaler and Bostock 2004 ; Lorenzo and Solano
2005 ; Fernández-Calvo et al. 2011 ; Niu et al. 2011 ). Furthermore, ABA functions
as a crucial regulator of P. Rapae -induced resistance in systemic tissues by acti-
vating primed JA-regulated defense responses in Arabidopsis (Vos et al. 2013 ).
Research in Nicotiana attenuata also demonstrated that the ABA signaling was
required for OS-triggered defense responses partly by enhancing the accumulation
of the JA and its associated responses (Dinh et al. 2013 ). In Dionaea muscipula ,
the ABA signaling pathway was used to protect the carnivore from untimely prey
catching during periods of drought, while the jasmonate signaling pathway plays
essential roles in signaling systemically the presence of a predator and also subse-
quently eliciting secretions (Escalante-P←rez et al. 2011 ). Thus, ABA and JA can
synergistically or separately function in plant responses to insect attack.
20.12 Roles of ABA in Plant-Virus Interaction
The interaction between plants and viral pathogens reflects a sophisticated coevo-
lution of recognition, defense, and counter-defense mechanisms. Because of the
limited genetic information encoded by the virus genome, plant viruses must
depend entirely on host cells to replicate their genome and produce infectious
progeny, during which they should use a variety of strategies to suppress or bypass
host defense. In plants, these strategies involve enhancing infection by manipu-
lating host resources, such as the formation of replication complexes (Hills et al.
1987 ), enlargement of the plasmodesma (PD) size exclusion limit (Wolf et al.
1989 ; Waigmann et al. 1994 ), evolution of viral suppressors of RNA silencing
(VSRs) to counteract antiviral silencing (Burgyán and Havelda 2011 ), interference
with regulation of the plant cell cycle (Gutierrez 2000 ; Lai et al. 2008 ), and usage
of host components for its own replication (Cui et al. 2007 ). In turn, plants have
developed diverse defense mechanisms to fight viral infection, such as HR and
SAR responses, RNA silencing, hormone-mediated signaling pathways, as well as
regulation of metabolism (Durrant and Dong 2004 ; Seo et al. 2004 ; Herbers et al.
1996 ; Chen et al. 2010 ; Ding and Voinnet 2007 ; Ding 2010 ). Numerous reports
have demonstrated that several plant hormones, such as SA, ET, and ABA, are
involved in plant basal defense responses in plant-virus interactions. Here, we will
mainly talk about the role of ABA in plant antivirus defense.
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