Wheat is an important cereal crop that serves two purposes: feed for the global community and support for the nation’s economy. Average wheat production worldwide is over 700 million tons, with China, India, the United States, the Russian Federation, and France being the top five wheat producers. The main exporters of wheat are the United States, Canada, France, Australia, and Russia, whereas the main importers are Egypt, Italy, Brazil, Japan, and Algeria (http://faostat.fao.org/). The overall production and trade of wheat reflects its significant role and demand in the global population. Approximately 95% of the total wheat produced worldwide is hexaploid bread wheat (Triticum aestivum sp. Aestivum, AABBDD, 2n = 6x = 42), whereas the remaining 5% is tetraploid durum wheat (Triticum turgidum sp. Durum, AABB, 2n = 4x = 28), also known as pasta wheat. The dough-forming ability of wheat flour increases the product range of wheat into bread, pasta, noodles, and biscuits. The key components responsible for dough formation are the grain storage proteins called gluten in wheat flour, whose interactions with water upon kneading form a proteinaceous structure (Shewry, 2019). Starch is another important component of wheat that promotes dough formation and causes gelatinization. In total, mature wheat grains contain approximately 13% water, 71% carbohydrates, 11% proteins, 2% lipids, 2% minerals, and 0.1% vitamins and phytochemicals, contributing significantly to human health (Wieser et al., 2020). Wheat has undoubtedly contributed significantly to global food security; however, wheat production is at great risk owing to climate change. As a C3 crop, wheat may benefit from high CO₂ concentrations in the environment by improving water-use efficiency, photosynthesis, and transpiration. However, the grain quality can be negatively affected by higher levels of CO₂. At higher temperatures, wheat productivity may decline because of a shorter crop season and an increase in transpiration (Bouras et al., 2019). A report published in Nature Climate Change estimated the impact of rising temperatures on global wheat yield using three independent models. The results indicated that the per degree rise in temperature can decline wheat productivity by 4.1%–6.4% (Liu et al., 2016). Various studies have shown that increasing temperature can have a drastic effect on wheat grain quality by shortening the grain-filling period, which will affect the gluten composition of wheat. High temperatures can change the ratio of gliadin to glutenin, weakening the dough-making properties of wheat flour. Moreover, extended heat waves and high temperatures can reduce the nitrogen level and, ultimately, the protein content of the grain (Wang and Liu, 2021b). In conclusion, climate change is going to impact wheat; therefore, the development of climate-tolerant wheat, which is difficult through conventional breeding techniques due to its hexaploidy genome, is an utmost priority. CRISPR/Cas9 technology was successfully used to obtain stable inherited mutations in wheat. Agrobacterium-mediated transformation has been used to deliver CRISPR constructs into immature wheat embryos (Howells et al., 2018; Zhang Z. et al., 2019). CRISPR/Cas9 genome editing-derived transgene-free wheat plants have also been produced using biolistic and protoplast transfection methods (Liang et al., 2017; Zhang et al., 2016). These studies have successfully implemented CRISPR/Cas9 genome editing technology in wheat, providing a platform for improving wheat concerning climate change-mediated problems. Grain weight, grain size, and grain yield per plant are the main agronomic attributes highly influenced by abiotic and biotic factors. Researchers have identified several genes that function as negative regulators of grain’s weight, size, and overall yield. For example, Receptor-like protein kinase 1 (RPK1), the Brittle rachis gene (BTR1-A), GASR7, TaSPL13, GW2, and TaARE1 (Table 1). A study reported the knockout of GASR7 and GW2 genes via the ribonucleoprotein (RNP)-derived CRISPR/Cas9 approach in bread wheat and pasta wheat resulted in transgene-free mutants with higher grain weight (Zhang Y. et al., 2021). Similarly, the TaSPL13 gene, responsible for controlling grain size and number, was edited using CRISPR/Cas9 (Gupta et al., 2023). The results revealed that mutations in this gene lead to an increase in the size and number of grains in allohexaploid wheat, demonstrating the importance of TaSPL13 in the evolution of yield-related attributes in wheat. Similarly, Ta-eIF4E alone has been targeted in wheat, resulting in viral resistance and improved plant height and grain length (Kan et al., 2023). Another important agronomic factor in wheat is early heading. Recently, the role of the thioredoxin gene (TaTRXH9) is characterized and validated in wheat using CRISPR/Cas9-mediated gene editing, and a loss-of-function mutation in this gene found in early-heading wheat (Fan et al., 2023). These studies reveal the success of CRISPR/Cas9 genome editing in improving wheat yield, which can significantly mitigate the impact of climate change on yield reduction.

The unstable weather can increase gluten levels in wheat, which makes it less suitable for consumption (Mkhabela et al., 2022). However, Chinese researchers have developed a Gluten gene Enrichment and Sequencing (GlutEnSeq) system, screened thousands of prolamin genes from different wheat varieties, and low gluten wheat was produced by modifying γ- and a-gliadin genes via CRISPR/Cas9 (Jouanin et al., 2019). A study developed improved winter and spring wheat varieties with high amylose content via CRISPR/Cas9-mediated genome editing of starch-branching enzyme (SBE) II (TaSBEIIa), and multiple transgene-free mutant lines were obtained (Li J. et al., 2021). Correspondingly, the CRISPR/Cas9 approach has been utilized to modify four genes, i.e., puroindoline b (PINb), granule-bound starch synthase gene (GBSS or WAXY), polyphenol oxidase gene (PPO), and phytoene synthase gene (PSY), in wheat via the Agrobacterium-mediated transformation method of gene delivery (Zhang Y. et al., 2021; Zhang Z. et al., 2019). The PINb gene controls grain hardness, the WAXY gene is responsible for amylose synthesis, PSY is the main gene controlling the carotenoid biosynthetic pathway, and PPO controls color via the oxidation of phenolic compounds.

Micronutrient deficiency in wheat is likely to occur because of increasing temperatures and drought, which can lead to malnutrition and other health disorders. The CRISPR/Cas9 genome editing approach is a straightforward method that can be used to enhance the nutritional composition of wheat and address this problem; for instance, Ibrahim et al. edited the Inositol Pentakisphosphate 2-Kinase 1 (TaIPK1) gene, which expresses an enzyme involved in the final step of the phytate biosynthesis pathway (Ibrahim et al., 2022). Phytic acid is considered an anti-nutrient because it reduces the bioavailability of iron and zinc in humans. The phytic in wheat tissues binds to these micronutrients as phytate and decreases their bioavailability. CRISPR/Cas9 genome engineering of TaIPK1 in wheat improved iron (1.5–2.1-fold) and zinc content (1.6–1.9-fold) and lowered phytic acid accumulation in wheat grains. Several agronomic improvements via CRISPR/Cas9-mediated genome editing in wheat are presented in Table 1.

Transcriptome profiling of wheat grains revealed several heat stress-associated gene, including heat shock transcription factor gene (TaHSFA6e), ascorbate peroxidase, β-amylase, γ-gliadin-2, and LMW-glutenin, were upregulated during the high-temperature stress (Rangan et al., 2020; Wen et al., 2023). Such studies can help select the potential target genes for CRISPR/Cas-mediated genome editing, which might lead abiotic stress resistant crops. Moreover, studies on different crops can be used to develop wheat that is tolerant to increasing temperatures caused by climate change. For example, CRISPR/Cas9-mediated knockout of the mitogen-activated protein kinase gene (SlMAPK 3) enhances heat tolerance in tomato plants, and the edited pyrabactin resistance 1 (PYR1)/PYR1-like (PYL) (pyl1/4/6) makes rice tolerant to hot weather (Miao et al., 2018; Yu et al., 2019). Since wheat is hexaploid and has a complex genome, there are fewer reports available on producing abiotic stress-tolerant wheat plants than rice. TaSAL1, TaMBF1c, and TaHAG1 genes have been edited to produce abiotic stress-tolerant wheat plants (Mohr et al., 2022; Tian et al., 2022; Zheng M. et al., 2021). The histone acetyltransferase (TaHAG1) gene contributes to salt tolerance by affecting free radical production in hexaploid wheat. MBF1c confers thermotolerance by regulating the translation of specific mRNA translation, whereas SAL1 negatively regulates drought tolerance (Table 1). These studies suggest that genome editing of wheat could be a promising approach for conferring climate change.

Rice (Oryza sativa L.) is a staple crop, with a global consumption rate of approximately 21% and 76% in Asian countries. Worldwide, 776.5 million tons of rice were produced in 2022, with approximately 90.5% of the average rice production taking place in Asia, in which China and India are the biggest producers (). This high demand for rice is due to its taste and versatility in a variety of international cuisines (Castanho et al., 2023). In addition, rice is enriched in nutrients, mainly complex carbohydrates, and moderate levels of vitamin B, phosphorous, iron, calcium, and protein. Most nutrients (minerals, vitamins, proteins, and antioxidants) are present in the rice brain, which has a brown outer layer. Rice contains all essential amino acids except lysine and is a great source of a balanced diet, as it does not contain cholesterol, fat, or sodium (Sasaki and Burr, 2000). However, the current climate change scenarios have adversely affected rice crops from farms to consumers in various ways (Zhao et al., 2016). Increasing temperature, carbon dioxide, drought, salinity, rainfall, pests, and diseases are the main stressors that can directly affect various rice attributes, such as grain size, quality, yield, nutritional constitution, and appearance. Rice cultivation can be successful if the optimum temperature and rainfall are provided; however, an increase of 1 °C can adversely affect rice yield. A recent study showed a decline in the nutritional content of rice due to rising atmospheric CO₂ concentrations. Micronutrients, proteins, and several vitamins are diminished in rice, leading to malnutrition in infants and children of rice-dependent countries. A decline of approximately 17%–30% in vitamins, 5% in zinc, 8% in iron, and 10% in protein was observed in rice grown under high CO₂ conditions (Smith and Myers, 2018). In contrast, Guo et al. found a 15% increase in the mineral content of rice grown under high CO₂ and temperature conditions (Guo et al., 2022). Though high CO₂ is normally considered a growth-stimulating agent along with high temperature, it acts antagonistically. Jing et al. reported reduced rice yield due to elevated temperatures under high CO₂ conditions created using temperature-free air CO₂ enrichment (T-FACE) systems (Jing L. et al., 2024). Another T-FACE experiment in China reported that increasing CO₂ substandardized the sensory quality of rice by increasing chalkiness (Wang et al., 2024d). The chalkiness of rice is a major obstacle to rice marketing. Chalky rice forms owing to abnormal starch development inside the grain and appears as a scattered coarse material, thus making the surface turbid. This abnormal starch accumulation occurs due to the high temperature, mainly at the time of grain filling, which reduces the ability of α-amylase enzyme to degrade the starch and, hence, leads to malformed starch synthesis (Shimoyanagi et al., 2021). In addition to grain quality, other issues in rice that can occur due to climate change include decreased shoot biomass and carbohydrate content in the stem, decreased starch content, and reduced photosynthetic ability, transpiration, and leaf area (Cui et al., 2024; Huanhe et al., 2024; Yamori et al., 2025). Hence, concerning the future outcomes, researchers have been trying different strategies, one of which is the robust and versatile genetic editing technique called as CRISPR/Cas9 system for generating climate-smart rice crops. CRISPR/Cas9-mediated gene editing has been optimized in rice using Agrobacterium-mediated transformation, particle bombardment, and RNPs (Miao et al., 2013; Shan et al., 2013). Moreover, a multiplexing approach was successfully established for rice. Recently, a group of researchers accomplished ultra-multiplexing targeting 49 genes in rice using both Agrobacterium-mediated and biolistic approaches (Wu et al., 2024).

CRISPR/Cas9 mediated-knockout of two main quantitative trait loci associated with grain length and thousand-grain weight, i.e., GS3 and GL3.1 was reported in rice GS3 encodes a protein that restrains the cell division of the spikelet hull, leading to shorter grains, whereas GL3.1 encodes an enzyme that controls grain size by dephosphorylating the cell cycle-related protein Cyclin-T1,3 and inhibits cell proliferation in the hull. Mutations in this gene increase grain size in rice (Yuyu et al., 2020; Zhang Y. M. et al., 2021). Huang et al. used the CRISPR/Cas9 technique to create an Indica maintainer line, Mei1B, containing an edited GS3 allele to improve grain yield and quality (Huang et al., 2022). Another study mutated the OsSPL16 or GW8 gene via CRISPR/Cas9 technology to improve the cylindrical shape and grain yield of Basmati rice (Usman et al., 2021). Rice aroma is an important quality parameter that is affected by climate change. Nevertheless, improving and introducing aromas into rice is feasible to improve and introduce aromas into rice using genetic engineering techniques. Mutations in Betaine Aldehyde Dehydrogenase 2 (OsBADH2) via CRISPR/Cas9 added aroma to elite non-aromatic rice variety (Hui et al., 2022; Tang et al., 2021). Several reports are available on the use of CRISPR-mediated gene editing for improving various agronomic traits in rice (Table 2). Recently, loss-of-function mutants of OsCKX were found to affect various attributes including plant height, grain size, grain number, panicle size, seed shape, and starch accumulation. This gene encodes a cytokinin-degrading enzyme that inactivates cytokinins, which plays important roles in plant growth and cell proliferation (Zheng et al., 2023). Similarly, enhanced grain yield was observed by deleting a target site of the transcription factor An-1 in the cis-regulatory region of the Ideal Plant Architecture 1 (IPA1) gene (Song et al., 2022).

Rice quality improvement is crucial because rice passes through various downstream processes, such as dehydration, milling, removal of bran, cleaning, and cooking after harvesting, and each process directly or indirectly decreases the nutrient content of rice. For instance, cleaning alone can reduce vitamin levels by 25%–60%, potassium by 20%–40%, and proteins by 3%–7% in rice (Müller et al., 2022). Combining this with the effect of climate change, the rice produced would not be useful. Therefore, biofortification is the only method that can sustain rice nutrients. Carotenoid-enriched marker-free rice has been developed by inserting two carotenoid biosynthetic genes, SSU-CRTI and ZmPSY30, using the CRISPR/Cas9 approach (Dong et al., 2020). Achary and Reddy produced a rice variety with an enhanced accumulation of iron, zinc, potassium, calcium, and phosphorous in endosperm via CRISPR/Cas9-mediated editing of GW2 (Grain width and grain weight) locus (Achary and Reddy, 2021). Moreover, the aleurone layer gained thickness with an enhanced protein content. Another study found decreased grain chalkiness, high ammonium cation, and phosphate ion uptake, and high photosynthetic activity under high CO₂ conditions in miR166-RDD1 knocked-out rice plants (Iwamoto, 2022).

Among abiotic stressors, salinity is a serious event that can potentially tarnish rice production. The development of salt-tolerant varieties is a lifesaving approach feasible with CRISPR/Cas9 genome editing technology. High salt concentrations can negatively affect crop production by disrupting the metabolic and physiological processes. These factors can significantly affect plant development, seed germination, and productivity (Zörb et al., 2019). Plants respond to salt stress by increasing the biosynthesis of antioxidants, osmoregulators, and phytohormones that support the plant by maintaining ion homeostasis; however, this ability works to a certain extent, and not all plants can protect themselves from high salinity (Raza et al., 2022). Similarly, drought stress drastically affects the physiology of plants by inhibiting nutrient uptake and other life-dependent activities, including photosynthesis, cell division and elongation, turgor pressure, and gene expression. Several rice genes have been identified and mutated using CRISPR/Cas9 to produce abiotic stress-tolerant plants (Table 2). For example, salt-tolerant T2 homozygous mutant rice was developed by cleaving the OsRR22 gene in rice using Cas9 (Zhang A. et al., 2019). Knockout of OsRR22 improved the performance of rice plants under high-salt conditions (0.75%), with no side effects on grain size, yield, or plant biomass. The same strategy was used by Han et al. to develop novel rice germplasm at the seedling stage (Han et al., 2022). In another study, the drought and salt tolerance (OsDST) gene was edited using CRISPR/Cas9 to produce the indica mega rice cultivar MTU1010 with enhanced tolerance (Santosh et al., 2020). In rice, the transcription factor OsMADS26 plays a negative role, and mutations in this gene enhance drought tolerance (Anjala and Augustine, 2022). Ogata et al. characterized the Enhanced Response to ABA1 (ERA1) gene in rice using CRISPR/Cas9-mediated editing and found frameshift mutations in mutants with increased primary root growth, high sensitivity to abscisic acid stress, and increased drought stress tolerance (Ogata et al., 2020).

The effect of climate change on disease susceptibility in rice poses a major threat to rice productivity. Climate change-induced pest and microbial emergence can annihilate agriculture, thereby substantially threatening food security. Fortunately, this can be mitigated using gene-editing applications in crops. Various studies have been published on the production of pests and microorganisms that cause disease tolerance in crops (Liu M. et al., 2024; Oliva et al., 2019; Zhou et al., 2022). Table 2 shows some examples of CRISPR/Cas9-mediated development of disease-resistant plants. However, the current work is insufficient in comparison to the upcoming consequences of climate change because this change can also increase the potential of insects by providing them with favorable conditions for their growth and development. For example, fruit flies flourished more when the temperature increased from 20°C to 35 °C in certain mango varieties. This phenomenon is observed in all species worldwide. In particular, insects in temperate regions have become more active, whereas populations of tropical insects may decline or migrate (Bhattacharjee et al., 2022). Therefore, genetically edited plants may be a powerful solution for overcoming the effects of climate change on agriculture. Several studies have been conducted to develop rice resistance to various fungal and bacterial pathogens. Xa13 is involved in pollen development and exhibits recessive resistance to bacterial blight. Studies have shown that the complete loss of function of the coding region of this gene can lead to sterility; therefore, CRISPR-assisted modification was performed in the Xa13 promoter region to produce transgene-free bacterial blight-resistant rice with retained fertility (Li C. et al., 2020). Another study targeted three salicylic acid 5-hydroxylase (OsS5H) genes (BSR-D1, PI21, and ERF922) in rice and found resistance to both rice blast and bacterial blight (Zhou et al., 2022). Recently, rice with enhanced immunity was produced by editing the NAC transcription factor gene in rice via CRISPR/Cas9 approach (Son et al., 2024). Furthermore, broad-spectrum disease resistance was achieved by editing three salicylic acid hydroxylase (OsS5H) genes in rice (Li X. et al., 2023).

Maize (Zea mays) is the most important cereal crop in the world, with the highest production after rice and wheat, and fulfills the needs of human food, animal feed, and biofuels (Chávez-Arias et al., 2021). Maize is sensitive to heat stress during seed germination and vegetative growth. It significantly affects maize plant germination and seedling emergence. Heat stress causes the formation of abscisic acid and affects the activity of enzymes responsible for breaking down starch (Chandra et al., 2023). Additionally, it inhibits the synthesis of proteins in the embryo, which reduces the germination of maize seeds at over 37°C, resulting in a decrease in plant density (Buriro et al., 2011). Increased oxidative stress, altered membrane permeability, decreased stomatal conductance, and other signs occur regularly in plants under heat stress. The rate of photosynthesis was negatively affected by a reduction in stomatal conductance. Moreover, it induces the production of reactive oxygen species and causes oxidative stress (Soengas et al., 2018; Zandalinas et al., 2017). Heat stress negatively affects the number of florets, silk number, fertilization, filling, development, and final grain yield during flowering (Lizaso et al., 2018). Recently, the continuous span of heat waves has affected maize yield and productivity. They alter the morphology, physiology, genomic expression, and biochemical metabolism of crops. In response to these alterations, plants activate tolerance mechanisms via heat shock transcription factors and proteins essential for reducing and preventing heat-related damage (Li and Zhang, 2022d). Heat stress affects the integrity of the plasma membrane and the accumulation of reactive oxygen species (Dogra and Kim, 2020). Moreover, proteins are misfolded or unfolded, which disrupts cell metabolism and physiology and eventually leads to cell death. The development of climate resilience in maize is urgently needed because heat-induced decline is high in this crop (Chandra et al., 2023).

Currently, a decrease in yield resulting from drought stress is estimated to affect over 20% of the annual maize area, and at high temperatures, an average of 7.4% is lost for every 1°C increase (Boyer et al., 2013; Malenica et al., 2021). Notably, Brazil, the third largest producer of maize worldwide, showed a decrease in yield in the 2015–16 and 2020–21 growing seasons of approximately 18 and 23 Mt, correspondingly to losses of approximately 21% compared to the 2014–15 and 2019–20 seasons (Lopes Filho et al., 2023). These crop failures occurred in years marked by extreme drought conditions, resulting in diminished yields in many of the largest producer geographies. Similarly, crop yield reductions and spiking prices were affected by the 2012 drought in the US (the world’s largest producer) (Boyer et al., 2013). Therefore, it is essential to reduce the potential losses caused by the increased frequency, severity, and duration of stresses associated with global climate change by continuously developing new maize cultivars that target better genetic adaptation and using improved agricultural practices.

Abiotic stress tolerance and yield are two complex traits strongly influenced by environmental factors and linked to small-effect genetic loci. Using genomic engineering techniques to develop superior cultivars for these traits is more difficult because of such complexity, which makes it challenging to reliably evaluate the molecular mechanisms behind gene activities and measure phenotypes. Considering the few instances developed for complex traits, transgenic maize cultivars with enhanced herbicide and insect resistance have been on the market for decades (Yassitepe et al., 2021). The difficulty in applying a transgenic approach to control complex traits that are stable in multiple environments has limited the development of biotech cultivars that could be widely used (Simmons et al., 2021).

Gene editing technology has enabled an efficient and consistent way to understand the role of key genes and develop new germplasm in maize (Doll et al., 2019; Wang Y. et al., 2022).

Potential putative functions of numerous genes involved in maize development programs and stress responses have been investigated thoroughly using CRISPR/Cas9 technology (Wang Y. et al., 2022). CRISPR has been widely used to enhance numerous agronomic traits in maize, yield, nutrition, improved pollen characteristics, drought tolerance, and disease resistance (Jiang L. et al., 2024; Kaul et al., 2024; Lv et al., 2024; Wang G. et al., 2024; Xie Z. et al., 2024). ZmGDIɑ was specifically edited using CRISPR/Cas9 to significantly increase maize resistance to the maize rough dwarf virus without negative agronomic effects (Liu Y. et al., 2023). ZmCOIɑ interacts inversely with ZmJAZ15 to alter maize immunity against Gibberella stalk rot (GSR, a teleomorph of Gibberella zeae), and further downregulation of ZmCOIɑ can increase maize resistance to GSR (Ma et al., 2021). MMS21 maintains the activity and integrity of the maize genome, resulting in improved root and vegetative growth, pollen germination, and seed development (Zhang et al., 2021b). ZmCLCg positively regulates sodium chloride stress and chloride transport in maize as a stress response (Luo et al., 2021). ZmSRL5 is essential for sustaining cuticular wax structure and drought tolerance in maize (Pan Y. et al., 2020).

Maize yield is severely affected by several environmental factors, including drought, high temperatures, floods, and unsuitable soil conditions. The breeding of stress-tolerant variants has shown great potential when applying genome editing tools compared with conventional breeding methods (Chávez-Arias et al., 2021; Chennakesavulu et al., 2021; Prasanna et al., 2021). The development of maize lines with high stalk strength has become considerably important to breeders for maintaining high and constant production, as stalk lodging caused by different environmental factors poses a significant threat to maize quality and production. STIFF1 is a negative regulator of maize stalk length, its altered allele with a 2bp deletion caused a frameshift and an early slowdown translation, conferring CRISPR-edited plants with a stronger stalk, which contributed to high-density planting and avoided stalk lodging (Armarego-Marriott, 2020). Furthermore, ZmGA20OX3 has been modified to develop semi-dwarf maize plants using CRISPR/Cas9 technology, which may be useful for developing a novel genotype that is more resilient to lodging and suitable for high-density planting (Liu Y. et al., 2023). For drought tolerance, precisely editing the promoter sequence of ARGOS8 leads to an increase in its expression and enhances maize grain yield under drought stress (Shi et al., 2017). By inserting the GOS2 promoter from maize plants at the 5ʹ untranslated regions that remain of the ARGOS8 gene’s native promoter, which acts as a negative regulator of ethylene responses (Zafar et al., 2020). Targeted alteration of the native maize promoter using CRISPR/Cas9 enhanced ARGOS8 expression and improved grain production under drought conditions. In addition, CRISPR/Cas9 has been used to target Slagamous-Like 6 (SIAGL6) to achieve heat tolerance (Doll et al., 2019). Therefore, developing new germplasm sources for breeding stress-tolerant maize has been achieved using CRISPR/Cas9 technology. Table 3 illustrates several improvements in the agronomic traits of maize using CRISPR/Cas9 gene editing.