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Small RNAs – The Big Players in Developing Salt-Resistant Plants

gene expression in the cytoplasm by either degrading mRNAs or inhibiting

their translation (Huntzinger & Izaurralde, 2011; Zhang et al., 2019). Now a

days small RNA molecules, more specifically miRNAs are used as weapons

of superpower to combat abiotic stresses. Plant breeders and plant genetic

engineers develop a huge number of stress-resistant cultivars by using the

concept of RNAi technology. The yield of any plants growing under stress

conditions such as salinity conjointly depends on the survival of the plant

as well as the phenological and developmental plasticity of the plant. Such

miRNAs do not directly control the growth and development of plant,

but by influencing through a miRNA-target gene network, they indirectly

regulate the same. Emerging evidence also confirms the impact of miRNAs

on the cellular and physiological events of many plants, and as a result, it

is considered one of the valuable entities for crop improvement by plant

genetic engineers. Appropriate modulation of target genes/proteins can help

overcome PTGS, resulting in increased expression in treated plants.

Proper characterization of the functional feature of sRNAs together

with a whole-genome sequence of plant species of agriculture relevance is

also beneficial for transgenesis practice (Kumar et al., 2018). In addition,

such studies on sRNA mediated regulatory networks will also provide a

genetic basis for future research, including the research related to salt stress

responses (Xu et al., 2019). Since few sRNA-based strategies are widely

used in the study of seed germination in a normal and stressed conditions. By

applying the RNAi approach seed germination process has improved in many

plants through the down-regulation of lysine catabolism specifically when

an elevated level of lysine negatively influences the events of germination

(Zhu & Galili, 2004). In addition to gathering knowledge regulation of genes

related to the development of organ and cellular metabolism sRNA-based

strategy has also been implicated to enrich the understanding of constitutive

silencing of gene-poor, repetitive sections of eukaryotic genomes, which are

typically clustered at centromeres and telomeres (Johnson & Straight, 2017).

In plants and some animals, miRNAs and many types of siRNAs execute

post-transcriptional RNA interference (RNAi) as an adaptive response

(Xie et al., 2004). RNAi technology has now become a powerful tool for

crop improvement as it: (i) provides high throughput genotype-phenotype

mapping in the plant; (ii) can also be implemented for rapid identification of

biochemical pathways related to biogenesis phytoconstituents; and (iii) can

also enable as an eco-friendly green alternative to conventional chemical

pesticides by imparting resistance against bacteria, fungi, insects, and diverse

plant viruses (Zhang et al., 2020).