Molecular Breeding Technologies Research Articles

A Simple Narrative Review of Progress on the Processing and Utilization of Functional Rice

This paper aims to review the research progress on the processing and utilization of functional rice and explore its potential to enhance human health. The research progress in the processing and utilization of colored rice, low-protein rice, high-resistant starch rice, micronutrient-enriched rice, and bioreactor rice was systematically analyzed through a comprehensive literature review. The impact of various processing techniques on the retention of nutritional components in functional rice was also discussed. This study found that functional rice exhibits great potential in terms of nutritional value, health effects, and market demand. However, issues such as the loss of bioactive components during processing, the maintenance of specific agronomic traits, and market acceptance still need to be addressed. The research and development of functional rice are significant for enriching people’s dietary choices and addressing global malnutrition and chronic disease problems. Future efforts should focus on further optimizing processing techniques and utilizing genetic engineering and molecular breeding technologies to enhance the nutritional value and agronomic traits of functional rice, thus meeting market demands and health objectives.

Gap-free telomere-to-telomere haplotype assembly of the tomato hind (Cephalopholis sonnerati)

The tomato hind (Cephalopholis sonnerati) is an emerging economically important grouper in recent years. With the increasing maturity of sequencing technologies and assembly methodologies, a higher quality reference genome has become both accessible and necessary. In this study, we present two telomere-to-telomere (T2T) gap-free haplotype assemblies of the tomato hind with lengths of 1039.53 Mb (YSFRI_Csonn_HA_1.0, N50 43.83 Mb) and 1039.91 Mb (YSFRI_Csonn_HB_1.0, N50 44.09 Mb). Reads from next-generation sequencing, ONT ultra-long sequencing, and PacBio HiFi sequencing exhibited mapping rates exceeding 99.8% when aligned to these two assemblies. Evaluation using Merqury indicated high accuracy for both assemblies, with average quality values of 51.80 and 51.83, respectively. Percentages of 97.9% and 97.8% of complete BUSCOs were achieved, and a total of 23,270 and 23,184 protein-code genes were inferred in each assembly. Moreover, telomere identification, centromere prediction, and repetitive sequence annotation were also successfully performed. These two assemblies provide robust foundation for the genetic analysis and development of molecular genetic breeding technologies in C. sonnerati.

Comparative proteomic analysis provides insights into wood formation in immature xylem at different ages in Eucalyptus urophylla × Eucalyptus grandis.

Wood formation is a crucial developmental stage in the life cycle of a woody plant; this process has substantial scientific research implications and practical applications. However, the mechanisms underlying woody plant development, especially the process of wood formation, remain poorly understood. As eucalyptus is one of the fastest growing tree species in the world, understanding the mechanism of wood formation in eucalyptus will greatly promote the development of molecular breeding technology for forest trees. In this study, we investigated the proteomic profile of immature xylem at four different ages of Eucalyptus urophylla × Eucalyptus grandis (E. urograndis) using iTARQ technology. We identified 5236 proteins and 492 differentially abundant proteins (DAPs). The expression profiles of the DAPs corresponding to coding genes associated with wood formation were assessed using qRT-PCR. From the different expression profiles, it is inferred that the genes encoding kinesin, CDKD3, EXPA13, EXPA2, XTH27, EGases, UGT76E2, LAC, CCoAMT, CesA3, PAL, and CAD may undergo posttranscriptional regulation (PTR). Additionally, the genes encoding EIN2, ETR, MC4-like, and XCP may undergo posttranslational modifications (PTMs). We investigated changes in wood formation-related proteins at the protein abundance level in the immature xylem of E. urograndis, thereby elucidating potential regulatory mechanisms of key proteins involved in eucalyptus wood formation. This study may provide theoretical guidance for further research on molecular breeding techniques and genetic improvement related to the cultivation of rapidly growing and high-quality trees.

De novo assembly of Idesia polycarpa transcriptome and unsaturated fatty acid biosynthesis candidate genes Mining and functional Identification

Unsaturated fatty acids (UFA) in lipids are the key to nutraceutical oil applications, with various potential applications in nutraceutical functional foods and pharmaceutical industries. In Idesia polycarpa (Salicaceae), more than 80 % of UFA have been found in the fruits; yet, the underlying genetic mechanism remains poorly understood. Due to the lack of theoretical research on the genes related to lipid biosynthesis and the complete genetic transformation system of I. polycarpa fruit, the selection and breeding of I. polycarpa, an excellent oil tree, has been severely restricted. In-depth understanding of the molecular mechanism and gene function of lipid biosynthesis of I. polycarpa fruit is therefore of great significance for the development of I. polycarpa resources. This is not only conducive to the genetic improvement of I. polycarpa by molecular breeding technologies but can also provide a reference for the study of the gene functions of other oil plants. In this study, the FA accumulation patterns of I. polycarpa fruits during 8 growth periods were analysed. Fruit from two developmental periods with different UFA levels were analysed for RNA sequencing by an Illumina NovaSeq 6000 HiSeq platform. De novo transcriptome assembly presented 115,350 unigenes and 4382 differentially expressed genes (DEGs). Functional annotation in the KEGG pathway and combined with DEG data revealed candidate genes potentially involved in UFA biosynthesis. Expression analysis of q-PCR of IpDGAT2, IpGPAT, IpKASII, IpSAD, IpFAD2, IpFAD3 and IpFAD8 suggested that these genes are highly involved in UFA biosynthesis. Full-length candidate genes were cloned and analysed by bioinformatic tools, and function analysis of IpSAD and IpFAD3 showed that these genes regulated the products of linoleic acid metabolism. This study provides a foundation for UFA biosynthesis in Idesia polycarpa, facilitating its genetic breeding in the future.

A review on prospect of wheat in Nigeria: Technological Advancement in Focus

The main issue affecting domestic wheat production in Nigeria is environmental incompatibility— the fact that wheat, being a temperate crop, requires cold climates during the growing season to thrive especially during the critical developmental stage between tillering and grain filling. This has limited the wheat growing season in Nigeria, to the cool harmattan period starting from November to March, and the wheat growing areas in Nigeria, along latitude 10°N to 14°N. Unfortunately, the harmattan period itself is also challenged by the absence of a rainy season, which typically starts after the period from April to September with unfavourable high temperature and humidity. Nigerian government policies over the years have centred on accelerating primary production (farming) instead of focusing on addressing the main issues, through research and development of cultivars that will be adaptable in Nigeria’s heat-stressed growing environment, build more irrigation areas along the harmattan latitude, strengthen extension services to ensure farmers adherence to Good Agronomic Practices (GAPs) and ease farmers access to market for fair prices. As a result, the national average ton per hectare output is abysmally 1.3 MT, prepared irrigation area is less than 10% of planned area and a near-complete disconnect between farmers and the off-taking flour milling industry, who are currently fully reliant on imported wheat. The peculiar situation is like in other tropical countries like Egypt, Ethiopia and the warm and humid Bangladesh. The paper recommended the adoption of molecular breeding technologies to strengthen the breeding processes and shorten the seeds generation time.

Genome-wide association analysis identify candidate genes for feed efficiency and growth traits in Wenchang chickens

BackgroundWenchang chickens are one of the most popular local chicken breeds in the Chinese chicken industry. However, the low feed efficiency is the main shortcoming of this breed. Therefore, there is a need to find a more precise breeding method to improve the feed efficiency of Wenchang chickens. In this study, we explored important candidate genes and variants for feed efficiency and growth traits through genome-wide association study (GWAS) analysis.ResultsEstimates of genomic heritability for growth and feed efficiency traits, including residual feed intake (RFI) of 0.05, average daily food intake (ADFI) of 0.21, average daily weight gain (ADG) of 0.24, body weight (BW) at 87, 95, 104, 113 days of age (BW87, BW95, BW104 and BW113) ranged from 0.30 to 0.44. Important candidate genes related to feed efficiency and growth traits were identified, such as PLCE1, LAP3, MED28, QDPR, LDB2 and SEL1L3 genes.ConclusionThe results identified important candidate genes for feed efficiency and growth traits in Wenchang chickens and provide a theoretical basis for the development of new molecular breeding technology.

Genome-wide identification and characterization of SPXdomain-containing genes family in eggplant.

Phosphorus is one of the lowest elements absorbed and utilized by plants in the soil. SPX domain-containing genes family play an important role in plant response to phosphate deficiency signaling pathway, and related to seed development, disease resistance, absorption and transport of other nutrients. However, there are no reports on the mechanism of SPX domain-containing genes in response to phosphorus deficiency in eggplant. In this study, the whole genome identification and functional analysis of SPX domain-containing genes family in eggplant were carried out. Sixteen eggplant SPX domain-containing genes were identified and divided into four categories. Subcellular localization showed that these proteins were located in different cell compartments, including nucleus and membrane system. The expression patterns of these genes in different tissues as well as under phosphate deficiency with auxin were explored. The results showed that SmSPX1, SmSPX5 and SmSPX12 were highest expressed in roots. SmSPX1, SmSPX4, SmSPX5 and SmSPX14 were significantly induced by phosphate deficiency and may be the key candidate genes in response to phosphate starvation in eggplant. Among them, SmSPX1 and SmSPX5 can be induced by auxin under phosphate deficiency. In conclusion, our study preliminary identified the SPX domain genes in eggplant, and the relationship between SPX domain-containing genes and auxin was first analyzed in response to phosphate deficiency, which will provide theoretical basis for improving the absorption of phosphorus in eggplants through molecular breeding technology.

Genetic structural analysis of different breeds and geographical groups of Fenneropenaeus chinensis reveals population diversity

Fenneropenaeus chinensis is a commercially important shrimp species cultured in China. This study investigated eight F. chinensis populations in China, including four geographical populations, three commercial breeds, and one wild population captured from the Yellow Sea. Population stratification analysis revealed that the Hebei geographical population and commercial breeding “Huanghai No. 4” were relatively independent and stable, reflecting a relatively closed breeding environment, whereas gene introgression was present between other populations. Selective signature analysis detected artificial selection for vision, growth, and disease resistance in the Hebei population. Neuronal development-related genes were detected to be under selection in the Changyi and Rizhao populations. Fertility of the Rizhao population was also investigated. Additionally, genes in the glycosaminoglycan biosynthesis-chondroitin sulfate/dermatan sulfate pathway were involved in the high pH tolerance of the “Huanghai No. 4” population. This study provided support for the genetic mechanism of parsing economic traits and the development of molecular breeding technologies.

Host-induced gene silencing of the Verticillium dahliae thiamine transporter protein gene (VdThit) confers resistance to Verticillium wilt in cotton

Verticillium wilt (VW), induced by the soil-borne fungus Verticillium dahliae (Vd), poses a substantial threat to a diverse array of plant species. Employing molecular breeding technology for the development of cotton varieties with heightened resistance to VW stands out as one of the most efficacious protective measures. In this study, we successfully generated two stable transgenic lines of cotton (Gossypium hirsutum L.), VdThit-RNAi-1 and VdThit-RNAi-2, using host-induced gene silencing (HIGS) technology to introduce double-stranded RNA (dsRNA) targeting the thiamine transporter protein gene (VdThit). Southern blot analysis confirmed the presence of a single-copy insertion in each line. Microscopic examination showed marked reductions in the colonization and spread of Vd-mCherry in the roots of VdThit-RNAi cotton compared to wild type (WT). The corresponding disease index and fungal biomass of VdThit-RNAi-1/2 also exhibited significant reductions. Real-time quantitative PCR (qRT-PCR) analysis demonstrated a substantial inhibition of VdThit expression following prolonged inoculation of VdThit-RNAi cotton. Small RNA sequencing (sRNA-Seq) analysis revealed the generation of a substantial number of VdThit-specific siRNAs in the VdThit-RNAi transgenic lines. Additionally, the silencing of VdThit by the siVdThit produced by VdThit-RNAi-1/2 resulted in the elevated expression of multiple genes involved in the thiamine biosynthesis pathway in Vd. Under field conditions, VdThit-RNAi transgenic cotton exhibited significantly enhanced disease resistance and yield compared with WT. In summary, our findings underscore the efficacy of HIGS targeting VdThit in restraining the infection and spread of Vd in cotton, thereby potentially enabling the development of cotton breeding as a promising strategy for managing VW.

UAV image acquisition and processing for high‐throughput phenotyping in agricultural research and breeding programs

AbstractWe are in a race against time to combat climate change and increase food production by 70% to feed the ever‐growing world population, which is expected to double by 2050. Agricultural research plays a vital role in improving crops and livestock through breeding programs and good agricultural practices, enabling sustainable agriculture and food systems. While advanced molecular breeding technologies have been widely adopted, phenotyping as an essential aspect of agricultural research and breeding programs has seen little development in most African institutions and remains a traditional method. However, the concept of high‐throughput phenotyping (HTP) has been gaining momentum, particularly in the context of unmanned aerial vehicle (UAV)‐based phenotyping. Although research into UAV‐based phenotyping is still limited, this paper aimed to provide a comprehensive overview and understanding of the use of UAV platforms and image analytics for HTP in agricultural research and to identify the key challenges and opportunities in this area. The paper discusses field phenotyping concepts, UAV classification and specifications, use cases of UAV‐based phenotyping, UAV imaging systems for phenotyping, and image processing and analytics methods. However, more research is required to optimize UAVs’ performance for image data acquisition, as limited studies have focused on the effect of UAVs’ operational parameters on data acquisition.

Knowledge mapping analysis of the development of molecular breeding technology for beef cattle in China

Abstract With China’s economic and social development, material living standards have improved, leading to a dramatic increase in the demand for beef and higher requirements for its quality. In this context, molecular breeding technology for beef cattle has gradually become a research hotspot. This paper designs the entire process of knowledge mapping for molecular breeding technology of beef cattle in China, focusing on the molecular breeding knowledge extraction model based on BERT. It also integrates models and algorithms used in knowledge alignment, complementation, and storage to construct the knowledge graph. After testing the performance of the knowledge extraction algorithm, the development history of molecular breeding technology for beef cattle in China was analyzed. The results show that from 2013 to 2023, research related to molecular breeding technology for beef cattle in China exhibited a slow, then rapid growth trend. The terms “molecular breeding” and “beef cattle” appeared most frequently, with 218 and 165 occurrences, respectively, and had the highest centrality. Keywords with high occurrences include “comparative genes” (11.3068), “functional genes” (9.2376), “genome-wide association” (8.3197), and “genome-wide selection” (6.9012), all closely related to the development of molecular breeding technology for beef cattle in China. The prediction of future trends in molecular breeding technology for beef cattle in China is significantly influenced by this study.

Transcriptome profiling reveals SLC5A5 regulates chicken ovarian follicle granulosa cell proliferation, apoptosis, and steroid hormone synthesis

The egg-laying performance of hens holds significant economic importance within the poultry industry. Broody inheritance of the parent stock of chickens can result in poor options for the improvement of egg production, and is a phenomenon influenced by multiple genetic factors. However, few studies have been conducted to delineate the molecular mechanism of ovarian regression in brooding chickens. Here, we explored the pivotal genes responsible for the regulation of ovarian follicles in laying hens, using RNA-sequencing analysis on the small ovarian follicles from broody and laying chickens. Sequencing data analysis revealed the differential expression of 200 genes, with a predominant enrichment in biological processes related to cell activation and metabolism. Among these genes, we focused on solute carrier family 5 member 5 (SLC5A5), which exhibited markedly higher RNA expression levels in follicles from laying compared with broody chickens. Subsequent cellular function studies with knockdown of SLC5A5 in chicken ovarian follicle granulosa cells (GCs) led to the down-regulation of genes associated with cell proliferation and steroid hormone synthesis, and concurrent promotion of gene expression linked to apoptosis. These findings indicated that SLC5A5 deficiency led to the inhibition of proliferation, steroid hormone synthesis and secretion, and promotion of apoptosis in chicken GCs. Our study demonstrated a pivotal role for SLC5A5 in the development and function of chicken GCs, shedding light on its potential significance in the broader context of chicken ovarian follicle development, and providing a prospective target to improve the egg-laying performance of chickens via molecular marker-assisted breeding technology.

Characterization and fine mapping analysis of a major stable QTL qKnps-4A for kernel number per spike in wheat.

A major stable QTL for kernel number per spike was narrowed down to a 2.19-Mb region containing two potential candidate genes, and its effects on yield-related traits were characterized. Kernel number per spike (KNPS) in wheat is a key yield component. Dissection and characterization of major stable quantitative trait loci (QTLs) for KNPS would be of considerable value for the genetic improvement of yield potential using molecular breeding technology. We had previously reported a major stable QTL controlling KNPS, qKnps-4A. In the current study, primary fine-mapping analysis, based on the primary mapping population, located qKnps-4A to an interval of approximately 6.8-Mb from 649.0 to 655.8 Mb on chromosome 4A refering to 'Kenong 9204' genome. Further fine-mapping analysis based on a secondary mapping population narrowed qKnps-4A to an approximately 2.19-Mb interval from 653.72 to 655.91 Mb. Transcriptome sequencing, gene function annotation analysis and homologous gene related reports showed that TraesKN4A01HG38570 and TraesKN4A01HG38590 were most likely to be candidate genes of qKnps-4A. Phenotypic analysis based on paired near-isogenic lines in the target region showed that qKnps-4A increased KNPS mainly by increasing the number of central florets per spike. We also evaluated the effects of qKnps-4A on other yield-related traits. Moreover, we dissected the QTL cluster of qKnps-4A and qTkw-4A and proved that the phenotypic effects were probably due to close linkage of two or more genes rather than pleiotropic effects of a single gene. This study provides molecular marker resource for wheatmolecular breeding designed to improve yield potential, and lay the foundation for gene functional analysis of qKnps-4A.

Drought and salinity stresses induced physio-biochemical changes in sugarcane: an overview of tolerance mechanism and mitigating approaches.

Sugarcane productivity is being hampered globally under changing environmental scenarios like drought and salinity. The highly complex nature of the plant responses against these stresses is determined by a variety of factors such as genotype, developmental phase of the plant, progression rate and stress, intensity, and duration. These factors influence plant responses and can determine whether mitigation approaches associated with acclimation are implemented. In this review, we attempt to summarize the effects of drought and salinity on sugarcane growth, specifically on the plant's responses at various levels, viz., physiological, biochemical, and metabolic responses, to these stresses. Furthermore, mitigation strategies for dealing with these stresses have been discussed. Despite sugarcane's complex genomes, conventional breeding approaches can be utilized in conjunction with molecular breeding and omics technologies to develop drought- and salinity-tolerant cultivars. The significant role of plant growth-promoting bacteria in sustaining sugarcane productivity under drought and salinity cannot be overlooked.

Muscle transcriptome analysis provides new insights into the growth gap between fast- and slow-growing Sinocyclocheilus grahami.

Sinocyclocheilus grahami is an economically valuable and famous fish in Yunnan Province, China. However, given its slow growth (40g/2 years) and large growth differences among individuals, its growth performance needs to be improved for sustainable future use, in which molecular breeding technology can play an important role. In the current study, we conducted muscle transcriptomic analysis to investigate the growth gaps among individuals and the mechanism underlying growth within 14 fast- and 14 slow-growth S. grahami. In total, 1,647 differentially expressed genes (DEGs) were obtained, including 947 up-regulated and 700 down-regulated DEGs in fast-growth group. Most DEGs were significantly enriched in ECM-receptor interaction, starch and sucrose metabolism, glycolysis/gluconeogenesis, pyruvate metabolism, amino acids biosynthesis and metabolism, peroxisome, and PPAR signaling pathway. Some genes related to glycogen degradation, glucose transport, and glycolysis (e.g., adipoq, prkag1, slc2a1, agl, pygm, pgm1, pfkm, gapdh, aldoa, pgk1, pgam2, bpgm, and eno3) were up-regulated, while some genes related to fatty acid degradation and transport (e.g., acox1, acaa1, fabp1b.1, slc27a1, and slc27a2) and amino acid metabolism (e.g., agxt, shmt1, glula, and cth) were down-regulated in the fast-growth group. Weighted gene co-expression network analysis identified col1a1, col1a2, col5a1, col6a2, col10a1, col26a1, bglap, and krt15 as crucial genes for S. grahami growth. Several genes related to bone and muscle growth (e.g., bmp2, bmp3, tgfb1, tgfb2, gdf10, and myog) were also up-regulated in the fast-growth group. These results suggest that fast-growth fish may uptake adequate energy (e.g., glucose, fatty acid, and amino acids) from fodder, with excess energy substances used to synthesize collagen to accelerate bone and muscle growth after normal life activities are maintained. Moreover, energy uptake may be the root cause, while collagen synthesis may be the direct reason for the growth gap between fast- and slow-growth fish. Hence, improving food intake and collagen synthesis may be crucial for accelerating S. grahami growth, and further research is required to fully understand and confirm these associations.

Genetic dissection of drought resistance for trait improvement in crops

Reliance on agriculture for food security is a constant in all modern societies. Global climate change and population growth have put immense pressure on sustainable agriculture, exacerbating the effects of environmental stresses. Drought is one of the most pressing abiotic stresses that farmers face, presenting an annual threat to crop growth and yield. Crops have evolved extensive morphological, physiological, and molecular mechanisms to combat drought stress. Drought resistance is a polygenic trait, controlled by a complex genetic network and an array of genes working together to ensure plant survival. Many studies have aimed at dissecting the genetic mechanisms underlying drought resistance. Recent studies using linkage and association mapping have made progress in identifying genetic variations that affect drought-resistance traits. These loci may potentially be engineered by genetic transformation and genome editing aimed at developing new, stress-resistant crop cultivars. Here we summarize recent progress in elucidating the genetic basis of crop drought resistance. Molecular-breeding technologies such as marker-assisted selection, genome selection, gene transformation, and genome editing are currently employed to develop drought-resistant germplasm in a variety of crops. Recent advances in basic research and crop biotechnology covered in this review will facilitate delivery of drought-resistant crops with unprecedented efficiency.

Genomic and genetic advances of oiltea-camellia (Camellia oleifera).

Oiltea-camellia (C. oleifera) is a widely cultivated woody oil crop in Southern China and Southeast Asia. The genome of oiltea-camellia was very complex and not well explored. Recently, genomes of three oiltea-camellia species were sequenced and assembled, multi-omic studies of oiltea-camellia were carried out and provided a better understanding of this important woody oil crop. In this review, we summarized the recent assembly of the reference genomes of oiltea-camellia, genes related to economic traits (flowering, photosynthesis, yield and oil component), disease resistance (anthracnose) and environmental stress tolerances (drought, cold, heat and nutrient deficiency). We also discussed future directions of integrating multiple omics for evaluating genetic resources and mining key genes of important traits, and the application of new molecular breeding and gene editing technologies to accelerate the breeding process of oiltea-camellia.

Deciphering cotton genomic variations for “genes to jeans”

Genomic variation includes inter- and intraspecific variation. The former is the genetic footprint of species speciation and domestication. The latter is the within-species variation caused by spontaneous mutation that has been maintained through natural and artificial selection. Characterizing interspecific genomic variations of a crop helps us to understand its genetic diversity and evolution trajectory. Deciphering intraspecific genomic variations and linking them to phenotypic outcomes sheds light on how natural and artificial selection has shaped the crop and provides targets for improving its performance through molecular breeding technologies.

Transcriptome analysis of the Mizuhopecten yessoensis gills under high temperature fluctuations

AbstractTemperature is one of the environmental factors affecting the physiological activities of aquatic animals. This study explored the gene expression and regulation mechanism in the gill tissues of the scallop Mizuhopecten yessoensis under the stress of high temperature fluctuations. We designed a high temperature fluctuation experiment, in which the water temperature was raised from 20°C to 23°C and 26°C and then decreased from 26°C to 23°C and 20°C, with a rate of heating and cooling of 0.5°C/h. The experiment consisted of four cycles and lasted for 7.5 days. When the target temperature was reached and the next temperature increase or decrease began, the gills of scallops were collected to measure immune enzyme activities and for transcriptome analysis. Immunological results showed significant differences in enzyme activities of catalase, superoxide dismutase, total antioxidant capacity, and lysozyme in scallop gills at 20°C on the first day and 26°C on the fifth day. Therefore, we analyzed gene expression from gill samples from these two time points using transcriptomics. We referred to samples from these time points as the normal temperature group (NT) and high temperature group (HT). Transcriptome results indicated that 347 differentially expressed genes (DEGs) were found in HT versus NT. Through gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, we found that these DEGs were mainly involved in metabolic pathways and protein synthesis pathways and had significant effects on oxidative stress, apoptosis, body metabolism, and protein folding in M. yessoensis. We selected 62 DEGs related to heat shock, immunity, and metabolism, including 47 upregulated and 15 downregulated DEGs. In a subset of these genes, quantitative real‐time PCR (qRT‐PCR) analysis showed similar expression (R2 = 0.81), thus validating the transcriptome data. Our results provide a theoretical basis for further analysis of the response mechanism in M. yessoensis to high temperature stress and for the development of molecular breeding technology for high temperature tolerance.

Applications and Prospects of CRISPR/Cas9-Mediated Base Editing in Plant Breeding

The clustered regularly interspaced short palindromic repeats (CRISPR)/associated protein 9 system (Cas9) has been used at length to optimize multiple aspects of germplasm resources. However, large-scale genomic research has indicated that novel variations in crop plants are attributed to single-nucleotide polymorphisms (SNPs). Therefore, substituting single bases into a plant genome may produce desirable traits. Gene editing by CRISPR/Cas9 techniques frequently results in insertions-deletions (indels). Base editing allows precise single-nucleotide changes in the genome in the absence of double-strand breaks (DSBs) and donor repair templates (DRTs). Therefore, BEs have provided a new way of thinking about genome editing, and base editing techniques are currently being utilized to edit the genomes of many different organisms. As traditional breeding techniques and modern molecular breeding technologies complement each other, various genome editing technologies have emerged. How to realize the greater potential of BE applications is the question we need to consider. Here, we explain various base editings such as CBEs, ABEs, and CGBEs. In addition, the latest applications of base editing technologies in agriculture are summarized, including crop yield, quality, disease, and herbicide resistance. Finally, the challenges and future prospects of base editing technologies are presented. The aim is to provide a comprehensive overview of the application of BE in crop breeding to further improve BE and make the most of its value.