Plant adaptation to environmental stress is a complex process that involves a range of molecular, physiological, and biochemical responses. In plant stress response research, the majority of investigations have focused on single biotic or abiotic elements; however, the simultaneous presence of both biotic and abiotic stresses can markedly influence plant growth, productivity, and viability (Park and Park, 2019). To cope with these multiple stresses, plants initiate a range of signaling pathways and regulatory processes to preserve homeostasis and adapt to changing environmental conditions. The UPR is one such mechanism; it is a conserved response found across eukaryotic organisms, including plants, and plays a critical role in cellular adaptation to stress (Chakraborty et al., 2016). The UPR has emerged as a crucial regulatory mechanism in plant adaptation to combined biotic and abiotic stresses, allowing plants to cope with the challenges posed by their environment.

Under heat stress conditions, protein folding becomes perturbed, and several ER membrane-associated transcription factors relay stress signals to the nucleus, which in turn activates stress-responsive genes (Fragkostefanakis et al., 2016; Reyes-Impellizzeri and Moreno, 2021). It has been discovered that in diverse plant species, such as Arabidopsis thaliana (Arabidopsis) and Zea mays (maize), heat stimulation causes IRE1 to splice bZIP60 mRNA (Deng et al., 2011; Li et al., 2012; Neill et al., 2019). The expression of active bZIP60 also elevates the transcription of heat shock protein (HSP) genes, suggesting a link between the UPR and the heat shock response mechanism (Li et al., 2020c). The transcription factor bZIP28 regulates the expression of UPR-related genes in response to heat stress conditions via a proteolytic mechanism, which triggers the translocation of bZIP28 to the nucleus (Iwata et al., 2017). Drought and salt significantly impact plant development and yield. In response to salt stress, bZIP17 is cleaved by site-1 proteases (S1P) and translocated to the nucleus to activate UPR genes (Liu et al., 2007b). It has been shown that the transcription factors bZIP60 and bZIP17 orchestrate the expression of the molecular chaperone gene, luminal-binding protein 3 (BiP3), as well as several genes implicated in the response to salt stress conditions (Henriquez-Valencia et al., 2015). Elevated expression of BiP has been observed to augment drought tolerance in a variety of plant species, such as Glycine max (soybean), Nicotiana tabacum (tobacco), and Arabidopsis (Coutinho et al., 2019). Infection by pathogens has been shown to induce ER stress in plants, with the IRE1-bZIP60 signaling pathway playing a crucial role in mounting a defense against the fungal pathogen, Alternaria alternate (Xu et al., 2019). Plants with mutations in IRE1 and bZIP60 are more susceptible to bacterial and viral infections (Moreno et al., 2012). In Nicotiana benthamiana, UPR was activated by the Geminivirus satellite-encoded βC1, which induces the nuclear export of NbbZIP60 to evade the plant defense response (Zhang et al., 2023). Overall, these findings indicate that various biotic and abiotic factors can disrupt protein folding capacity and activate the UPR in plants. As environmental stresses continue to impact global agriculture, the role of the UPR in facilitating plant adaptation to combined biotic and abiotic stresses is becoming a more significant area of research. Investigating the function of the UPR in plants has the potential to enhance crop improvement and sustainable agriculture practices, making the study of UPR activation in response to stress in plants increasingly important for agricultural research.

In situations of excessive or prolonged ER stress, where UPR mechanisms cannot restore protein folding, the ERAD system facilitates the clearance of terminally aberrant proteins, thus maintaining ER homeostasis (Vembar and Brodsky, 2008; Hwang and Qi, 2018). The ERAD comprises a multistep process, which includes the identification of cargo proteins, retro-translocation of substrates to the cytoplasm through an ER membrane channel, ubiquitination of ER proteins by ubiquitin enzymes, and subsequent degradation of ubiquitinated substrates via the 26S proteasome ( Figure 1 ) (Chen et al., 2020). The ERAD machinery has been extensively studied in yeast and mammals (Ye et al., 2001; Sato et al., 2009; Avci and Lemberg, 2015; Habeck et al., 2015; Schoebel et al., 2017). In recent years, several ERAD components have been identified and characterized in plants (Chen et al., 2022). The N-glycans of misfolded proteins are recognized by osteosarcoma amplified 9 (OS9), which associates with the suppressor enhancer Lin12 1 like (Sel1L)/HMG-CoA reductase degradation protein 3 (Hrd3)/HMG-CoA reductase degradation 1 (Hrd1) complex ( Figure 1 ) (Duwi Fanata et al., 2013). Protein associated with Hrd1-1/2 (PAWH1/2) interaction with EMS-mutagenized Bri1 suppressor 7 (EBS7) indirectly associates with Hrd1, regulating the stability and activity of the E3 ligase ( Figure 1 ) (Liu et al., 2015; Lin et al., 2019). Therefore, Hrd1 has the potential to target UBC32, an E2 enzyme located on the ER membrane of Arabidopsis. UBC32 is responsible for the ubiquitination of aberrant proteins that is induced by stress, leading to their subsequent degradation in the cytosol via the proteasome pathway ( Figure 1 ) (Cui et al., 2012; Chen et al., 2017; Chen et al., 2020).

ERAD, an important proteolytic pathway crucial to protein quality control, appears as a key factor in various studies associated with the enhancement of plant resistance to environmental stresses, productivity increase, and quality improvement. ERAD is a significant mechanism in plants for responding to environmental stresses, showing resistance capabilities to heat stress, drought, and salinity (Li et al., 2017; Strasser, 2018). In various plant species, evolutionarily conserved homologous ERAD components appear to be associated with stress tolerance and plant defense pathways elucidated two evolutionarily conserved ERAD pathways, DOA10 and HRD1, responding to heat stress in Arabidopsis (Liu and Li, 2014; Li et al., 2017; Strasser, 2018; Huber et al., 2021). This study demonstrated that loss-of-function mutants exhibited a higher survival rate and lower electrolyte leakage compared to the wild-type plants, enhancing plant resistance to heat stress (Li et al., 2017; Strasser, 2018). ERAD influences plant productivity by managing ER stress caused by protein misfolding. In this context, Ohta and Takaiwa (2015) showed that OsHrd3 is necessary for maintaining the quality of ER-derived protein bodies in rice endosperm (Ohta and Takaiwa, 2015). Additionally, Wakasa et al. (2011) proposed the possibility of improving the protein quality of rice through the role of ER stress response and ERAD (Wakasa et al., 2011). However, further research is necessary for a comprehensive understanding of ERAD associated with enhancing plant stress resistance, productivity, and quality.

The CRISPR-Cas system is an adaptive immune mechanism used by bacteria to defend against the invasion of bacteriophages (Mojica et al., 2005). The system comprises an endonuclease (Cas) and a guide RNA (gRNA) that together form a ribonucleoprotein complex. The Cas complex locates and binds to a target dsDNA with the help of the guidance of gRNA. Once the complex is activated, the Cas enzyme cleaves the phosphodiester bonds of both strands, creating a double-stranded break (DSB) in the target DNA (Barrangou et al., 2007). The cells repair the DSB using nonhomologous end-joining (NHEJ) or homologous recombination (HR) ( Figure 2A ), which may result in mutations or modifications in the DNA sequence, thereby achieving gene editing (Jinek et al., 2012; Cong et al., 2013; Dickinson et al., 2013; Schwank et al., 2013; Van Vu et al., 2019).

Since its repurposing for customized DNA cleavages and subsequent gene editing in 2012, the CRISPR era has begun (Jinek et al., 2012). The technology, recognized for its potential in precise genome engineering, has proven valuable in agriculture and various other fields, paving the way for numerous applications and advancements (Chen et al., 2019). As of today, there are two classes, six types, and over 30 subtypes of the CRISPR-Cas system that function in DNA or RNA targeting or other activities (Koonin and Makarova, 2022). The system has not only been repurposed as molecular scissors but also for other applications such as transcriptional regulations (Cheng et al., 2013; Qi et al., 2013). Furthermore, the editing scope has expanded from single bases ( Figure 2B ) (Komor et al., 2016; Gaudelli et al., 2017; Chen et al., 2021; Kurt et al., 2021; Tong et al., 2023) to small DNA changes with prime editing ( Figure 2C ) (Anzalone et al., 2019; Lin et al., 2020) and microhomology-mediated precision short DNA replacement (Tien Van et al., 2022), extending to kilobase-gene targeting, thereby establishing it as a versatile tool for genome editing (Dickinson et al., 2013; Schwank et al., 2013; Chen et al., 2019; Vu et al., 2020b).

The CRISPR-Cas system has been extensively utilized in plant biology and crop engineering, with a wide range of applications developed for editing target genes in both monocot and dicot species (Chen et al., 2019; Zhu et al., 2020). These applications include simple edits with indel mutations as well as HR-based precise gene replacement (Feng et al., 2013; Li et al., 2013; Nekrasov et al., 2013; Chen et al., 2019; Vu et al., 2020b). Due to the versatility of the CRISPR system, it has emerged as a valuable tool for achieving high efficiency in gene editing in plants, proving to be a significant asset in advancing plant biology and crop improvement research (Chen et al., 2019; Zhu et al., 2020; Tien Van et al., 2022).

The CRISPR-Cas system is a versatile tool with numerous applications, including gene functionalization and regulation. Cas9 complexes act like molecular scissors and can theoretically cleave any genomic site of interest if a PAM motif is present. Previously, researchers relied on knockout lines generated by T-DNA insertion, random mutagenesis, or RNA interference (RNAi)-based downregulation lines to assess gene function (Howell, 2013; Pucker et al., 2021). However, these methods have limitations such as complex T-DNA integration events (Tamura et al., 2016) or residual gene activity in downregulated lines (Santillan Martinez et al., 2020), which lead to complicated analysis. The emergence of CRISPR-Cas technology has revolutionized the study of gene function in plants, as knockout lines generated by CRISPR-Cas tools are more precise and cleaner than traditional methods (Tien Van et al., 2022). The CRISPR-Cas system is highly efficient, customizable, simple, and cost-effective, making it an accessible tool for labs worldwide (Ahmadzadeh et al., 2019; Chen et al., 2019; He et al., 2023).

Although CRISPR-Cas has been used extensively for gene regulation and functionalization since its discovery in 2012, its application in studying ER stress response is relatively recent and began in 2019 (Mishiba et al., 2019; Liu et al., 2020). Even though a few CRISPR-Cas-related studies have been conducted in this field, there is still considerable potential for further functional exploration of genes involved in ER stress signaling using this technology ( Tables 1 , 2 ). Early research using CRISPR-Cas to study ER stress response focused on the Arabidopsis genes Protein Associated with PAWH1 and PAWH2 ( Table 1 ) (Lin et al., 2019). These genes are essential components of the ERAD pathway (Lin et al., 2019) and play vital roles in mitigating environmental stress such as salinity (Liu et al., 2011). The PAWH genes were induced by ER stress and contributed to the stabilization of the UPR sensing complexes mediated by the EBS7 and Hrd1 (Lin et al., 2019). Additionally, the IRE1-mediated RNA splicing of AtbZIP60 is a critical aspect of the UPR pathway in ER stress responses (Yu et al., 2022). To investigate the role of IRE1b in the signaling arm, the sensor domain-coding region of the gene was deleted using dual gRNA CRISPR-Cas9 complexes in the ire1a/c mutant background ( Table 1 ) (Mishiba et al., 2019). The IRE1b-edited lines exhibited similar effects on BiP3 and PR-4 transcription as the ire1a/b mutant lines and bZIP60 RNA splicing as the ire1a/c mutants. However, there was no evidence of growth defects or seed set reductions in the mutant lines ( Table 1 ) (Mishiba et al., 2019).

In rice, the IRE1-mediated RNA splicing in ER stress responses is also conserved, and the OsbZIP74 (also known as OsbZIP50) is the ortholog of AtbZIP60 (Lu et al., 2012). Modified OsbZIP74 is transported to the nucleus and upregulates UPR-related genes, including several membrane-associated NAC transcription factors. In a recent study, researchers utilized the CRISPR-Cas9 gene-editing system to generate knockout mutants of OsNTL3, confirming its role as a transcriptional activator of OsbZIP74 ( Table 1 ) (Liu et al., 2020). The investigation also showed that OsbZIP74 positively regulates the transcription of OsNTL3 under heat stress conditions. Additionally, the study revealed that the loss of OsNTL3 function results in increased heat sensitivity in rice seedlings ( Table 1 ) (Liu et al., 2020). OsbZIP60 has been identified as a critical regulator of grain chalkiness, a stress-related phenotype in rice (Hayashi et al., 2012; Takahashi et al., 2012; Yang et al., 2022). To understand the role of OsbZIP60 in managing this response, osbzip60 knockout mutants were created using CRISPR-Cas9 gene-editing technology. In these mutants, upregulation of several chaperone genes, including OsbZIP50, OsBiP1, OsBiP2, and OsBiP3, was observed, leading to varying degrees of grain chalkiness. This result indicates that OsbZIP60 plays a critical role in regulating rice grain chalkiness and maintaining ER homeostasis ( Table 1 ) (Yang et al., 2022). In another study, the roles of two bZIP transcription factors, bZIP17 and bZIP28, in the UPR pathway were explored (Liu et al., 2007a; Liu et al., 2007b). The bzip17bzip28 double mutant displayed stress-related phenotypes, including severe dwarfism, low germination rate, and short roots, compared to the wild-type plant (Kim et al., 2018). To unravel the underlying mechanisms associated with the observed stress-related phenotypes, a suppressor mutant named nobiro6 was created within the bzip17bzip28 background using CRISPR-Cas9 technology. This triple mutant, bzip17bzip28nbr6, demonstrated a partial rescue of root growth, highlighting the role of NOBIRO6/TAF12b as a transcription cofactor in UPR-associated root growth control ( Table 1 ) (Kim et al., 2022b). In a recent study aiming to understand the role of NbbZIP60 in plant defense responses to pathogens, nbbzip60 knockout mutants were generated using CRISPR/Cas9-based technology (Zhang et al., 2023). These knockout mutant plants showed a reduced amount of viral DNA, leading to milder leaf curling symptoms compared to wild-type plants under virus infection ( Table 1 ). These findings highlight how CRISPR-Cas9 technology is enabling a deeper understanding of UPR in plants, opening avenues for enhancing plant stress resistance.

The CRISPR-Cas system offers a significant advantage in generating multiple gene mutations through multiplexing methods with multiple gRNAs. For instance, it was used to generate various mutated variants in single and combinations of UPR-related genes encoding for immune-associated nucleotide-binding (IAN) proteins in Arabidopsis ( Table 1 ) (Lu et al., 2021). In the study, IAN2 to IAN6 were found to be located at a single locus on chromosome 1 by genome-wide association study (GWAS) (Lu et al., 2021). The efficient CRISPR-Cas9 system was used to create single, double, triple, and quadruple IAN gene mutations that were crucial for gene functionalization. Interestingly, the ian mutants, particularly the ian6 knockout lines, exhibited enhanced heat tolerance during the reproductive stage in both Arabidopsis and rice ( Table 1 ) (Lu et al., 2021). The IAN6 protein has been discovered to localize to the ER, where it suppresses HSP and UPR-related gene expression and promotes programmed cell death during the reproductive stage ( Table 1 ) (Lu et al., 2021). In a similar manner, multiplexed editing has been effectively used to generate combined knockout mutations in genes associated with COPII-mediated vesicle trafficking from the ER to the Golgi apparatus (Chang et al., 2022). The COPII complex is involved in transporting bZIP28 proteins to the Golgi for processing and subsequent release into the cytosol during ER stress (Srivastava et al., 2012; Howell, 2013). In plants, Sec23 and Sec24 combine with Sar1 to form the inner layer of COPII vesicles. Several isoforms of the Sec23 were shown to form distinct ER exit sites with differential effects on protein trafficking and growth (Yoshihisa et al., 1993; Zeng et al., 2015). The sec23d mutant significantly hindered ER-to-Golgi transport, whereas the quintuple sec23abcfg mutant primarily impacted protein secretion to the plasma membrane ( Table 1 ) (Chang et al., 2022).

Plant responses to biotic stress, such as those induced by phytopathogens, require the maintenance of ER homeostasis. In rice, OsHLP1, which is induced by Magnaporthe oryzae infection, has been shown to interact with OsNTL6. This interaction suppresses the accumulation of OsNTL6, leading to the activation of genes involved in plant immunity and resulting in enhanced disease resistance (Meng et al., 2022). CRISPR-Cas9 knockout mutants of OsHLP1 displayed reduced disease resistance, suggesting that OsHLP1 positively regulates blast resistance in rice ( Table 1 ) (Meng et al., 2022). In contrast, the OsNTL6 protein acts as a negative regulator of blast disease resistance; overexpression lines led to increased Magnaporthe oryzae infection, while knockout lines generated using CRISPR-Cas9 showed reduced infection compared to wild-type plants ( Table 1 ) (Meng et al., 2022). Recent application of CRISPR-Cas technology in studying ER stress and plant responses to biotic stress has provided valuable insights into critical components of these pathways (Lin et al., 2019; Mishiba et al., 2019; Liu et al., 2020; Lu et al., 2021; Chang et al., 2022; Meng et al., 2022). By using CRISPR-Cas to edit the genome of plants, researchers can generate mutations in UPR-related genes to study their function and determine their role in the UPR pathway. Overall, the CRISPR-Cas system has revolutionized the field of genetics and has significant implications for the study of gene function in plants, including UPR-related genes.

Cis-regulatory elements (CREs) are noncoding DNA sequences that incorporate transcription factors and other molecular binding sites, such as promoters and enhancers, which influence transcription (Wittkopp and Kalay, 2011; Wolter et al., 2019). The promoter regions of most plant UPR-related genes contain a consensus cis-acting element known as the ERSE and/or the UPRE (Liu and Howell, 2010; Howell, 2013; Nawkar et al., 2017). Several studies have underscored the significant potential of crop improvement through the editing of regulatory sequences to adjust gene expression levels, thereby generating novel phenotypic variants (Wolter and Puchta, 2018; Wolter et al., 2019). For instance, the RAV2 gene, which is transcriptionally induced by salt stress in rice, was subjected to CRISPR-Cas-mediated engineering to modify the GT-1 element in the promoter, revealing that the GT-1 element directly governs the salt stress response ( Table 2 ) (Duan et al., 2016; Li et al., 2020b). In maize, ARGOS8, a negative regulator of ethylene responses, enhances drought tolerance ( Table 2 ) (Shi et al., 2015). Plants edited with CRISPR-Cas9 to replace the native promoter region of the ARGOS8 gene with the GOS2 promoter demonstrated increased grain yield under drought stress conditions in the field ( Table 2 ) (Shi et al., 2015; Shi et al., 2017; Wang et al., 2022). Similarly, the removal of a regulatory fragment containing a transcription-activator-like effector (TALe)-Binding Element (EBE) in the promoter of SWEET11 via CRISPR/Cas resulted in improved disease resistance in rice, without affecting fertility ( Table 2 ) (Li et al., 2020a). This development presents a clear advantage over the sterile phenotype of the Ossweet11 knockout mutant, which is unsuitable for crop improvement. Recently, genome editing of EBEs in SWEET promoter genes led to broad-spectrum bacterial blight resistance in rice ( Table 2 ) (Oliva et al., 2019). While predicting the effects of gene expression regulation by manipulation of various CREs, including ERSEs and UPREs, and the resulting phenotypic changes could be difficult, the modification of CREs by CRISPR-Cas holds the potential to be a critical strategy not only for studying UPR signaling pathways, but also for breeding plants with stress tolerance and desirable traits ( Figure 3A ).

The uORFs are essential regulatory elements located in the 5’ UTR of main open reading frames (mORFs). Recent bioinformatics analyses estimate that approximately 35% of total plant transcripts contain uORFs (Silva et al., 2019; Li et al., 2021). These uORFs are known to act as inhibitors, repressing the initiation of mORF translation via ribosome stalling (Silva et al., 2019; Zhang et al., 2020). A recent research indicates that uORFs possess the ability to regulate gene expression in response to environmental stresses, as they control specific master regulators involved in stress responses (Zhang et al., 2020). Under adverse environmental conditions, stress-responsive transcripts containing uORFs are upregulated, suggesting that CRISPR-Cas9-mediated uORF editing could be a promising approach to enhance gene expression for crop trait improvement ( Figure 3B ) (Um et al., 2021). For example, the application of CRISPR-Cas9 editing to the uORF of LsGGP2 in Lactuca sativa (lettuce) has yielded promising results, demonstrating increased tolerance to oxidative stress and a substantial 150% increase in ascorbate content ( Table 2 and Figure 3B ) (Zhang et al., 2018). Similarly, in Arabidopsis, TBF1 plays a critical role in the growth-to-defense transition in response to pathogen attack ( Table 2 ) (Traubenik et al., 2021). Under normal conditions, two uORFs in TBF1 inhibit AtTBF1 translation; however, upon pathogen infection, these inhibitory effects are relieved, allowing TBF1 to regulate and induce the expression of defense-related genes ( Table 2 and Figure 3B ) (Pajerowska-Mukhtar et al., 2012). These findings suggest that CRISPR-Cas-based gene editing can be used to remove or generate uORF sequences in target genes. This strategy can be used to increase or decrease protein translation levels, and applied to develop crops with improved traits, including stress resistance (Vuong et al., 2023). In conclusion, CRISPR-Cas9-mediated uORF editing represents a promising avenue for enhancing plant resilience to environmental stresses and advancing crop trait improvement.

Plant growth and development are significantly influenced by environmental conditions such as light (Bae and Choi, 2008; Kami et al., 2010; Paik and Huq, 2019). Suboptimal lighting conditions can trigger ER stress responses, which can lead to cellular dysfunction and ultimately affect plant growth and survival (Mawphlang and Kharshiing, 2017; Ahn et al., 2022). The connection between light and UPR has been shown to be mediated by ELONGATED HYPOCOTYL 5 (HY5), a bZIP factor previously known as a master regulator of light signaling (Gangappa and Botto, 2016). HY5 acts as an important transcription factor in both light signaling and the UPR pathway. In the dark, HY5 is targeted for degradation by the E3 ubiquitin ligase COP1, which marks HY5 with ubiquitin and targets it for degradation by the 26S proteasome (Ang et al., 1998; Xu et al., 2016). However, in the presence of light or under ER stress conditions, HY5 is stabilized and can regulate the expression of UPR-related genes (Nawkar et al., 2017). The HY5 gene has been identified as a critical regulator of stress resistance in plants (Xiao et al., 2021). Therefore, the utilization of CRISPR-Cas-based gene editing technology for the generation and characterization of crops carrying HY5 alleles may present a promising and compelling direction for further scientific investigation. Under various stress conditions, the levels and activity of HY5 protein increase, leading to enhanced expression of downstream genes. Overexpression or complete removal of the HY5 gene may result in significant trade-off in the phenotypes of edited lines, due to the important role of HY5 in multiple processes, such as photomorphogenesis. Consequently, generating mutants with HY5 alleles that maintain a certain level of expression could be an interesting approach for developing crops that efficiently respond to various stresses. The CRISPR-Cas-mediated generation of crops with HY5 alleles could be achieved by targeting the cis-regulatory elements of the HY5 gene. This approach has already been shown to be effective in previous studies (Rodriguez-Leal et al., 2017). Additionally, introducing CRISPR-Cas-mediated precise modification of the DNA binding bZIP domain or the COP1 binding domain in HY5 may be alternative strategies to alter HY5 functions. Such a strategy could be readily implemented through CRISPR-Cas-based gene targeting or prime editing (Van Vu et al., 2019). In summary, the regulatory function of HY5 in various stress responses makes it a promising target for enhancing stress tolerance in plants via CRISPR-Cas-based gene editing. By generating mutant alleles of HY5, it might be possible to indirectly alter the expression of downstream genes, including UPR-related genes, and consequently enhance the resistance of plants to various stresses.

Cadmium, a hazardous heavy metal, significantly impacts plants by interfering with crucial processes such as water and nutrient uptake, photosynthesis, calcium signaling, and genome maintenance. This interference leads to stunted growth, diminished yield, and in severe cases, plant death (Xi et al., 2016; De Benedictis et al., 2023). Recent studies have demonstrated that knockout of the supernumerary aleurone 1 (SAL1) enzyme can mitigate the toxicity of cadmium in Arabidopsis plants (Xi et al., 2016). SAL1, also known as FIERY1, is a well-established regulator of stress response signaling. This enzyme possesses 3’(2’),5’-bisphosphate nucleotidase and inositol polyphosphate 1-phosphatase functions (Quintero et al., 1996; Xiong et al., 2001; Wilson et al., 2009), and is implicated in leaf morphogenesis (Robles et al., 2010). These findings suggest that targeting SAL1 using CRISPR-Cas-based techniques could be a promising approach to alleviating cadmium toxicity and other environmental stresses in crop plants. By knocking out SAL1, plants may be better equipped to cope with environmental stresses, leading to improved crop yields and sustainability. In conclusion, the recent discovery of the role of SAL1 in mitigating cadmium-induced toxicity and ER stress responses offers an exciting opportunity for enhancing the sustainability of crop production. By utilizing CRISPR-Cas-based techniques to target SAL1 and other regulators of ER stress responses, crop plants may exhibit increased resilience to environmental stresses, ultimately leading to enhanced crop yield and quality. Taken together, the proposed strategies for improving crop stress tolerance through genetic modification present a promising opportunity for enhancing plant tolerance and agricultural productivity. By targeting key genes involved in stress responses, such as UBC32, HY5, and SAL1, it may be possible to develop crops that are better adapted to challenging environmental conditions. However, further research is necessary to identify the optimal genes for modification and ensure that the benefits outweigh any potential drawbacks.