VIGS technology has been extensively used to investigate function of genes
responsive to various kinds of abiotic stresses (Senthil-Kumar et al. 2007; Cho
et al. 2008; Govind et al. 2009; Kuzuoglu-Ozturk et al. 2012; Manmathan et al.
2013; Bao et al. 2015; Wang et al. 2016; Li et al. 2017b; Park et al. 2017;
Ramegowda et al. 2017; Ullah et al. 2018). Recent development in VIGS vectors
has extended the application of VIGS for functional characterization of abiotic
stress-responsive genes and also enhancing abiotic stress tolerance in several crops
including soybean. Rao et al. (2014) studied functional relevance of GmCam4
(Calmodulin) gene by silencing and over-expression using Bean Pod Mottle Virus
(BPMV)-based vector. Silencing of GmCam4 resulted susceptible response to salt
stress while over-expression resulted salinity tolerance in soybean plants at 200 mM
NaCl level (Rao et al. 2014). In the recent past, VIGS has been successfully used to
unravel the abiotic stress tolerance mechanisms in crop plants (Senthil-Kumar and
Udayakumar 2006; Senthil-Kumar et al. 2008; Manmathan et al. 2013). Zhou et al.
(2020) found that over-expressing gma-miR398c in soybean decreased GmCSD1a/
b, GmCSD2a/b/c, and GmCCS expression, which weakened the ability to scavenge
O 2
.À and by their means negatively regulates drought tolerance in soybean.
4.9.2 RNAi Approach: A Powerful Tool for Gene Function Studies
and Enhancing Drought Tolerance in Soybean
RNA interference (RNAi) is a versatile tool frequently used for gene function studies
in soybean. RNAi phenomenon involves small interfering RNA (siRNA) or short
hairpin or microRNA (miRNA) to suppress the expression of sequence-specific gene
at post-transcriptional or translational level. This technology has been extensively
used to study functional relevance of genes, enhancing crop yield, improvement of
nutritional quality, and increasing crop productivity through suppression of expression of genes responsive to abiotic stress, involved in biomass and grain yield.
In future, there will be huge demand for genetically improved crops with ability to
maintain yield stability under adverse environmental conditions. Drought stress
tolerance and adaptation of crop plants to drought stress have been improved through
RNAi approach for manipulating expression of transcription factor genes, genes
associated with signaling and biosynthetic pathways, and accumulation of
antioxidants (Gupta et al. 2014; Wang et al. 2015; Pradhan et al. 2015; Meena
et al. 2017; Li et al. 2017a). Several genes associated with drought stress-related
physiologies and pathways have been functionally characterized to understand stress
tolerance mechanisms and for improving abiotic stress tolerance in crop plants
(Zhou et al. 2015b; Guo et al. 2016; Ji et al. 2016; Ma et al. 2017; Li et al. 2017a;
Cai et al. 2018). It is utmost important to elucidate the role of transcription factors or
genes by genetic manipulation for higher yield and also yield stability under various
abiotic stress conditions. Several researchers tried to identify and characterize
various genes responsive to drought and salinity stress by using genomics,
transcriptomics, proteomics, and metabolomics approaches (Wang et al. 2015;
Tripathi et al. 2016b; Ji et al. 2016; Qin et al. 2016; Li et al. 2017a). Therefore, it
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G. K. Satpute et al.
responsive to various kinds of abiotic stresses (Senthil-Kumar et al. 2007; Cho
et al. 2008; Govind et al. 2009; Kuzuoglu-Ozturk et al. 2012; Manmathan et al.
2013; Bao et al. 2015; Wang et al. 2016; Li et al. 2017b; Park et al. 2017;
Ramegowda et al. 2017; Ullah et al. 2018). Recent development in VIGS vectors
has extended the application of VIGS for functional characterization of abiotic
stress-responsive genes and also enhancing abiotic stress tolerance in several crops
including soybean. Rao et al. (2014) studied functional relevance of GmCam4
(Calmodulin) gene by silencing and over-expression using Bean Pod Mottle Virus
(BPMV)-based vector. Silencing of GmCam4 resulted susceptible response to salt
stress while over-expression resulted salinity tolerance in soybean plants at 200 mM
NaCl level (Rao et al. 2014). In the recent past, VIGS has been successfully used to
unravel the abiotic stress tolerance mechanisms in crop plants (Senthil-Kumar and
Udayakumar 2006; Senthil-Kumar et al. 2008; Manmathan et al. 2013). Zhou et al.
(2020) found that over-expressing gma-miR398c in soybean decreased GmCSD1a/
b, GmCSD2a/b/c, and GmCCS expression, which weakened the ability to scavenge
O 2
.À and by their means negatively regulates drought tolerance in soybean.
4.9.2 RNAi Approach: A Powerful Tool for Gene Function Studies
and Enhancing Drought Tolerance in Soybean
RNA interference (RNAi) is a versatile tool frequently used for gene function studies
in soybean. RNAi phenomenon involves small interfering RNA (siRNA) or short
hairpin or microRNA (miRNA) to suppress the expression of sequence-specific gene
at post-transcriptional or translational level. This technology has been extensively
used to study functional relevance of genes, enhancing crop yield, improvement of
nutritional quality, and increasing crop productivity through suppression of expression of genes responsive to abiotic stress, involved in biomass and grain yield.
In future, there will be huge demand for genetically improved crops with ability to
maintain yield stability under adverse environmental conditions. Drought stress
tolerance and adaptation of crop plants to drought stress have been improved through
RNAi approach for manipulating expression of transcription factor genes, genes
associated with signaling and biosynthetic pathways, and accumulation of
antioxidants (Gupta et al. 2014; Wang et al. 2015; Pradhan et al. 2015; Meena
et al. 2017; Li et al. 2017a). Several genes associated with drought stress-related
physiologies and pathways have been functionally characterized to understand stress
tolerance mechanisms and for improving abiotic stress tolerance in crop plants
(Zhou et al. 2015b; Guo et al. 2016; Ji et al. 2016; Ma et al. 2017; Li et al. 2017a;
Cai et al. 2018). It is utmost important to elucidate the role of transcription factors or
genes by genetic manipulation for higher yield and also yield stability under various
abiotic stress conditions. Several researchers tried to identify and characterize
various genes responsive to drought and salinity stress by using genomics,
transcriptomics, proteomics, and metabolomics approaches (Wang et al. 2015;
Tripathi et al. 2016b; Ji et al. 2016; Qin et al. 2016; Li et al. 2017a). Therefore, it
110
G. K. Satpute et al.