## 4 Bio-Phytoremediation by Plants
### Genetic Engineering for Biodesalination  
Some well-proven, extensively utilized, and cost-effective conventional ameliorative measures (e.g., conservation agriculture and use of ecological conditioners) aid in the combat against salinity and other constraints, particularly in developing nations [64]. In recent decades, biologically engineered plants that are completely resistant to saline-alkali conditions have emerged as a new research focus both at home and abroad, with the objective of increasing plant productivity in saline-alkali soil [65]. Breeding and genetic concepts, such as the collection and incorporation of salt-tolerant genotype(s) through  
Figure 1: Strategies implicated in soil biodegradation by plants and microorganisms. traditional breeding, marker-assisted screening, molecular and transgenic strategies, and genome editing, have been in focus for a long time, and some remedies for the reduction of salt stress in crops have been successfully implemented [64]. The usual engineering approach to the problem is no longer sufficient. Genetic technology allows for the development of salt-tolerant crops, and, when combined with environmental modification, it might boost agricultural productivity in saline areas and expand agriculture to previously unsuitable areas [66]. For instance, water channel proteins (aquaporins) are important for water uptake/transport, particularly under stress circumstances; the overexpression of the wheat _TaNIP_ aquaporin gene in recombinant _Arabidopsis_ was found to improve salt resistance relative to wild-type seedlings [11]; and the wheat _TaAQP8_ aquaporin gene was found to increase recombinant tobacco salt resistance [23]. The realistic or perceived danger of horizontal gene transfer to associated wild or cultivated plants is a significant obstacle to the field implementation of transgenic plants for bioremediation. As a result, the next generation of transgenic plants will very certainly include methods that prohibit such a transmission, such as the incorporation of transgenes into chloroplast DNA or the usage of conditioned lethality genes [67]. There is significant genetic variation between halophytic genotypes [68], and the genotypes of some populations can function better in suboptimal environments [69]. Modern genetic manipulation technologies are now being used as an attempt to increase the biomass of salt-resistant plants [70]. The elaboration of expressed sequence tags (ESTs) and cDNA libraries utilizing multiple genomic strategies, such as serial analysis of gene expression (SAGE), suppressive subtractive hybridization (SSH), representational difference analysis (RDA), and differential display reverse transcription-polymerase chain reaction (DDRT-PCR) [71], has provided a massive database for the study of the genetic network involved in halophytes' abiotic stress resistance mechanisms [72; 73]. Various genes involved in stress tolerance have been identified from halophytes and cloned or overexpressed in bacterial systems, as well as sensitive glycoptive cultivars, using this methodology to boost stress tolerance and agricultural productivity [74]. The identification of genes operating in the network has relied heavily on the screening for mutations that impact the plant's response to stress. Designed screens include those aiming to identify mutations that increase or reduce salt sensitivity. The adoption of DNA microarray technology has also been useful, since it allows researchers to track changes in gene expression in response to stress and to identify genes that are either activated or repressed by the treatments [75]. Thus, the following techniques have been utilized to generate salt-tolerant crops through genetic engineering: boosting the plant's capacity to restrict salt ion intake from the soil; raising the salt ion active extrusion rate; and improving salt ion compartmentalization in the cell vacuole, where they have no effect on cellular processes.