suggested that the Tobacco 06G gene is a member of WRKY subfamily II that was
common in all virus infection-induced plant expression profiles and can be utilized
to enhance virus resistance in many plants (Zhou et al. 2014). Using techniques like
the Y2H system, co-immunopurification assay, and mutant lines of A. thaliana, the
binding of WRKY70 with RCY1-encoded CC-NB domain fragment was affirmed,
which directly confirmed the function of WRKY70 in resistance to a yellow strain of
CMV (Ando et al. 2014).
In another instance, the chrysanthemum WRKY11, a homolog of AtWRKY11 gets
upregulated after infection by all three viruses, namely CMV, TSWV, and Potato
virus X (Choi et al. 2015). Mandal et al. (2015) analyzed the promoter region of
SlTORNADO1, a gene important for the cell expansion, vein formation as well as
symptoms development during ToLCNDV infection. Their team confirmed the
SlWRKY16 active interaction with W-boxes present in the SlTORNADO1 promoter
region. Kundu et al. (2015) correlated the role of Vigna mungo WRKY in imparting
resistance to the mungbean yellow mosaic India virus (MYMIV) while working on
VMR84 (MYMIV-resistant) and T9 (susceptible) cultivars. Huh and colleagues
functionally characterized the control of MAPK-1 and -2 in CaWRKYa-based
L-mediated transcriptional reprogramming of PR gene expression during TMV
infection in hot pepper (Huh et al. 2015).
In the year 2016, the role of six tomato WRKYs (WRKY41, WRKY42, WRKY53,
WRKY54, WRKY80, and WRKY81) in TYLCV infection was elucidated using
subcellular localization analysis, interaction network analysis, and TRV-VIGS
(Huang et al. 2016). The overexpression and knockout studies of AtWRKY61 in
A. thaliana transgenic plants confirmed the negative correlation to Turnip crinkle
virus accumulation and symptoms which elucidated its role in plant immunity (Gao
et al. 2016).
Time-course analysis of the effect of Ugandan cassava brown streak virus
grafting on resistant and susceptible cassava varieties transcriptome revealed the
upregulation of differentially expressed-defense genes response genes including
LRR-containing, NBARC-containing, PR, LEA, WRKY, GATA, NAC, and HSPs
(Amuge et al. 2017). A similar kind of RNA-Seq study was conducted for cucumber
green mottle mosaic virus (CGMMV), a member of the Tobamovirus genus which
induces fruit decay in watermelon plants (Citrullus lanatus). Out of all 1621 DEGs,
various members of WRKY family such as WRKY13, WRKY31, WRKY46, WRKY48,
WRKY53, and WRKY70 were highly upregulated (Li et al. 2017). NtWRKY12 gene
expression is induced upon TMV infection and PAMP elicitation (Gullner et al.
2017). Similarly, microarray analysis coupled with GO and MapMan analysis of two
different ToLCNDV-resistant and susceptible potato cultivars also revealed there
were more than 3500 genes differentially regulated including multiple WRKY
family members (log2FC > 2) following the ToLCNDV infection (Jeevalatha
et al. 2017). All these published work together opened a list of multiple biomarkers
and candidate genes to be used in resistance breeding against viruses.
Recently, in an article published in Plant Cell Reports, Madronero and colleagues
conducted the global gene expression analysis on Papaya meleira virus complex
induced changes in infected papaya at pre-and post-flowering stages. At the
344
L. S. Rajput et al.
common in all virus infection-induced plant expression profiles and can be utilized
to enhance virus resistance in many plants (Zhou et al. 2014). Using techniques like
the Y2H system, co-immunopurification assay, and mutant lines of A. thaliana, the
binding of WRKY70 with RCY1-encoded CC-NB domain fragment was affirmed,
which directly confirmed the function of WRKY70 in resistance to a yellow strain of
CMV (Ando et al. 2014).
In another instance, the chrysanthemum WRKY11, a homolog of AtWRKY11 gets
upregulated after infection by all three viruses, namely CMV, TSWV, and Potato
virus X (Choi et al. 2015). Mandal et al. (2015) analyzed the promoter region of
SlTORNADO1, a gene important for the cell expansion, vein formation as well as
symptoms development during ToLCNDV infection. Their team confirmed the
SlWRKY16 active interaction with W-boxes present in the SlTORNADO1 promoter
region. Kundu et al. (2015) correlated the role of Vigna mungo WRKY in imparting
resistance to the mungbean yellow mosaic India virus (MYMIV) while working on
VMR84 (MYMIV-resistant) and T9 (susceptible) cultivars. Huh and colleagues
functionally characterized the control of MAPK-1 and -2 in CaWRKYa-based
L-mediated transcriptional reprogramming of PR gene expression during TMV
infection in hot pepper (Huh et al. 2015).
In the year 2016, the role of six tomato WRKYs (WRKY41, WRKY42, WRKY53,
WRKY54, WRKY80, and WRKY81) in TYLCV infection was elucidated using
subcellular localization analysis, interaction network analysis, and TRV-VIGS
(Huang et al. 2016). The overexpression and knockout studies of AtWRKY61 in
A. thaliana transgenic plants confirmed the negative correlation to Turnip crinkle
virus accumulation and symptoms which elucidated its role in plant immunity (Gao
et al. 2016).
Time-course analysis of the effect of Ugandan cassava brown streak virus
grafting on resistant and susceptible cassava varieties transcriptome revealed the
upregulation of differentially expressed-defense genes response genes including
LRR-containing, NBARC-containing, PR, LEA, WRKY, GATA, NAC, and HSPs
(Amuge et al. 2017). A similar kind of RNA-Seq study was conducted for cucumber
green mottle mosaic virus (CGMMV), a member of the Tobamovirus genus which
induces fruit decay in watermelon plants (Citrullus lanatus). Out of all 1621 DEGs,
various members of WRKY family such as WRKY13, WRKY31, WRKY46, WRKY48,
WRKY53, and WRKY70 were highly upregulated (Li et al. 2017). NtWRKY12 gene
expression is induced upon TMV infection and PAMP elicitation (Gullner et al.
2017). Similarly, microarray analysis coupled with GO and MapMan analysis of two
different ToLCNDV-resistant and susceptible potato cultivars also revealed there
were more than 3500 genes differentially regulated including multiple WRKY
family members (log2FC > 2) following the ToLCNDV infection (Jeevalatha
et al. 2017). All these published work together opened a list of multiple biomarkers
and candidate genes to be used in resistance breeding against viruses.
Recently, in an article published in Plant Cell Reports, Madronero and colleagues
conducted the global gene expression analysis on Papaya meleira virus complex
induced changes in infected papaya at pre-and post-flowering stages. At the
344
L. S. Rajput et al.