Antiviral Roles of Abscisic Acid in Plants

Abstract

Abscisic acid (ABA) is a key hormone involved in tuning responses to several abiotic stresses and also has remarkable impacts on plant defense against various pathogens. The roles of ABA in plant defense against bacteria and fungi are multifaceted, inducing or reducing defense responses depending on its time of action. However, ABA induces different resistance mechanisms to viruses regardless of the induction time. Recent studies have linked ABA to the antiviral silencing pathway, which interferes with virus accumulation, and the micro RNA (miRNA) pathway through which ABA affects the maturation and stability of miRNAs. ABA also induces callose deposition at plasmodesmata, a mechanism that limits viral cell-to-cell movement. Bamboo mosaic virus (BaMV) is a member of the potexvirus group and is one of the most studied viruses in terms of the effects of ABA on its accumulation and resistance. In this review, we summarize how ABA interferes with the accumulation and movement of BaMV and other viruses. We also highlight aspects of ABA that may have an effect on other types of resistance and that require further investigation.

Time-Course Microarray Analysis Reveals Differences between Transcriptional Changes in Tomato Leaves Triggered by Mild and Severe Variants of Potato Spindle Tuber Viroid

“…Genes related to JA, ET and SA, which play major roles in regulating plant defense responses to various pathogens, were generally up-regulated, but overall, the expression of more genes was differentially regulated in S23 and, unlike in M infection, these genes retained altered expression at 49 dpi ( Figure 6 ). ABA has a remarkable impact on plant defenses against various pathogens, including viruses [ 94 ]. Both ABA and SA influence callose deposition at the plasmodesmata (PD), a mechanism that limits cell-to-cell viral movement.…”

“…Plants control callose levels through the activity of hydrolytic enzymes called β-1,3-glucanases. ABA can enhance callose deposition in different tissues and organelles by transcriptional suppression of β-1,3-glucanases [ 94 ]. Induction of the genes encoding β-1,3-glucanases was observed during viral infections; this phenomenon resulted in the removal of callose and thereby facilitated viral trafficking [ 94 ].…”

Abscisic acid negatively modulates plant defence against rice black‐streaked dwarf virus infection by suppressing the jasmonate pathway and regulating reactive oxygen species levels in rice

“…Studies with both ABA-deficient and ABA-insensitive mutants showed that ABA played a positive role in TMV-cg infection . In Arabidopsis-BaMV interactions, ABA induced plant resistance against BaMV by regulating the expression of Argonaute 2 and 3 (Alazem et al, 2017).…”

“…In rice, ABA enhances plant defence against the brown spot fungal pathogen (De Vleesschauwer, Yang, Cruz, & Höfte, 2010), while it compromised host immunity to another fungal pathogen, Magnaporthe oryzae (Jiang et al, 2010). Against viral pathogens, ABA has only been shown to be involved in enhanced plant antiviral response (Alazem & Lin, 2017). Callose deposition at plasmodesmata (PD) and the RNA silencing pathway are thought to be the main ABA-dependent antiviral mechanisms (Alazem & Lin, 2017).…”

“…Against viral pathogens, ABA has only been shown to be involved in enhanced plant antiviral response (Alazem & Lin, 2017). Callose deposition at plasmodesmata (PD) and the RNA silencing pathway are thought to be the main ABA-dependent antiviral mechanisms (Alazem & Lin, 2017). Several studies have shown a positive correlation between ABA levels and resistance to tobacco mosaic virus (TMV; Chen, Zhang, Li, Wang, & Yu, 2013;Whenham, Fraser, Brown, & Payne, 1986).…”