Flooding is one of the most devastating abiotic stresses in agriculture, and enhancing flood tolerance is critical for sustainable crop production. Soybean (Glycine max) is highly susceptible to flooding stress. However,...Flooding is one of the most devastating abiotic stresses in agriculture, and enhancing flood tolerance is critical for sustainable crop production. Soybean (Glycine max) is highly susceptible to flooding stress. However, the molecular mechanism underlying soybean response to flooding stress remains largely unknown, and the genes available for improving soybean flood tolerance are relatively limited. In this study, we characterized the function of the predicted cytochrome P450 gene, GmSUR2, in regulating submergence tolerance in both soybean and Arabidopsis. The Arabidopsis SUR2 gene played a positive role in regulating submergence tolerance. The GmSUR2, which localizes to a previously identified quantitative trait locus (QTL) for waterlogging tolerance on soybean chromosome 03, shared conserved functions with AtSUR2 in regulating submergence tolerance. Transgenic soybean plants overexpressing GmSUR2 displayed enhanced submergence tolerance accompanied by reduced auxin levels. Further experiments revealed that auxin negatively regulates submergence tolerance: Exogenous auxin application decreased survival rates, and auxin signaling mutants exhibited improved tolerance. We also identified that GmAGL15 transcription factor directly repressed GmSUR2 expression. Importantly, field trials confirmed that GmSUR2 overexpression not only improved submergence tolerance but also increased the yield of transgenic soybean plants. Our findings provide new insights into the molecular mechanisms of submergence tolerance and establish GmSUR2 as a promising target for breeding flood-resistant soybean varieties.
An adenine base-editing system was established to precisely modify the sorghum SbALS gene, generating transgene-free mutant plants. These plants exhibit strong herbicide resistance, with no significant differences in agr...An adenine base-editing system was established to precisely modify the sorghum SbALS gene, generating transgene-free mutant plants. These plants exhibit strong herbicide resistance, with no significant differences in agronomic traits, providing valuable germplasm for herbicide-resistance breeding in sorghum.
Fu Y, Hu X, Shan Z
… +18 more, Yan H, Fan X, Zhu C, Yu T, Wang Y, Xu H, Niu S, Zhang W, Wang C, Du F, Ji Q, Gu C, Li Y, Ge X, Zhang Y, Jiang L, Zhang W, Wan J
Endosperm development plays a major role in determining rice grain quality and yield, whereas the mechanisms underlying the early developmental stages remain largely unknown. Grain size is also an important trait directl...Endosperm development plays a major role in determining rice grain quality and yield, whereas the mechanisms underlying the early developmental stages remain largely unknown. Grain size is also an important trait directly influencing rice yield and appearance quality. Here, we identified the b336 mutant that is defective in early grain development, characterized by elongated grains with floury and shrunken endosperm. Cytological analyses indicated defective cellularization and cell proliferation in early endosperm development of b336. The b336 mutation also decreased cell length but increased cell number/height of glumes and caryopses. Molecular cloning revealed that the b336 mutant contains a missense substitution in the β-tubulin protein OsTUB1. This dominant-negative mutation destabilized both OsTUB1 and α-tubulins post-transcriptionally and caused abnormal microtubule (MT) arrays in b336. Combined cellular, biochemical, and genetic evidence indicates that OsTUB1 acts synergistically with an MT-associated protein End-binding 1c (OsEB1c) to modulate endosperm development. Notably, OsEB1c overexpression rescued the floury phenotype of b336 endosperm and markedly reduced the abundance of mutant OsTUB1, suggesting that OsEB1c likely plays a quality control role in the assembly of mitotic MT arrays. OsTUB1 also interacted with OsEB1a to coordinately regulate grain size. Furthermore, partial functional redundancy was found between OsEB1a and OsEB1c. Strikingly, OsTUB1 or OsEB1c overexpression significantly enlarged grain size and enhanced grain quality. Natural variations in the promoter of OsTUB1 likely contribute to grain length variations across rice cultivars by modulating its expression. Together, our results identify OsTUB1-OsEB1c and OsTUB1-OsEB1a as distinct molecular modules that separately regulate endosperm development and grain size, and provide target genes for use in biotechnology to improve rice yield and quality.
Larriba E, Bres C, Alaguero-Cordovilla A
… +12 more, Riyazuddin R, Wang Q, Petit J, Mauxion JP, Caballero L, Latrasse D, Bakan B, Brik-Chaouche R, Esteve-Bruna D, Benhamed M, Rothan C, Pérez-Pérez JM
In contrast to animals, plants possess a remarkable regenerative capacity and are capable of forming new organs or even entire organisms from a limited number of cells present in adult tissues, in response to injury or e...In contrast to animals, plants possess a remarkable regenerative capacity and are capable of forming new organs or even entire organisms from a limited number of cells present in adult tissues, in response to injury or environmental changes. In this study, we describe the isolation and characterization of the more adventitious roots1-1 (mars1-1) mutant, which exhibits enhanced regenerative potential upon wounding in tomato hypocotyl explants. Additionally, the mars1-1 fruits exhibited a rough surface because of ectopic subepidermal cell proliferation, resulting in the formation of callus-like structures on their cuticle. The MARS1/ROUGH gene encodes a conserved lysine-specific histone demethylase, SlLDL1, which regulates processes such as cell proliferation, stem cell pluripotency, and embryogenesis in metazoans. Two CRISPR/Cas9 null alleles, mars1-2 and mars1-3, were generated, and their pleiotropic phenotypes were characterized. ChIP-seq analysis revealed elevated levels of methylated lysine 4 in histone 3 within specific regions of the mars1/rough genome. To determine the impact of altered epigenetic marks on gene expression regulation in mars1/rough mutants, we analyzed the transcriptome of tomato hypocotyls during adventitious root formation. Using specific bioinformatic workflows and the resolution of the directional RNA-seq data, we identified several dozen distinct genomic regions with de novo expression in the mars1/rough mutants. One such region includes a novel B-type cyclin gene that is upregulated in mars1/rough mutants and may account for adventitious root and fruit skin phenotypes. Our findings indicate that SlLDL1 plays a role in maintaining silencing in specific genomic regions that are essential for tissue-specific reprogramming.
Grain protein content (GPC) is well-known to negatively influence the eating and cooking quality in rice. However, the genetic mechanism underlying the natural variation of GPC is very limited. Here, we identify GPC6 as...Grain protein content (GPC) is well-known to negatively influence the eating and cooking quality in rice. However, the genetic mechanism underlying the natural variation of GPC is very limited. Here, we identify GPC6 as a key determinant through genome-wide association analysis. GPC6 encodes a protein with a MYB-like domain, functioning as a transcriptional repressor to modulate the expression of storage protein synthesis genes (Alb1, Pro13b.5, RM1, OsGluB1b, OsGluB7) and two regulators (RISBZ1 and PDIL1-1). Further, one functional SNP (-1,471 T/C) in the GPC6 promoter was identified, which defines two haplotypes: high-expression GPC6 (Low protein) and low-expression GPC6 (High protein). Notably, the GPC6 allele has been subject to artificial selection in modern East Asian japonica rice varieties. Collectively, these findings provide a crucial foundation for understanding the genetic mechanisms underlying the rice GPC variation and an important target gene for quality improvement practice.
This commentary examines recent work that explores the spatial organization of the plant internal sensors that detect infection and trigger immune responses, showing form small units that assemble into larger clusters at...This commentary examines recent work that explores the spatial organization of the plant internal sensors that detect infection and trigger immune responses, showing form small units that assemble into larger clusters at the cell surface. This spatial organization may strengthen defense signals and lead to controlled cell death.
Nucleus-encoded proteins are involved in intron splicing in plant chloroplasts. Although many splicing factors were discovered, the mechanisms for chloroplast intron splicing remain unknown. Here, we identified a P-class...Nucleus-encoded proteins are involved in intron splicing in plant chloroplasts. Although many splicing factors were discovered, the mechanisms for chloroplast intron splicing remain unknown. Here, we identified a P-class pentatricopeptide repeat (PPR) protein, PHOTOSYSTEM ONE BIOGENESIS FACTOR6 (PBF6), that is essential for the accumulation of photosystem I complex. PBF6 bound to ycf3 intron 1 and clpP1 intron 2, and the introns of petB, ndhA, and ndhB transcripts, and was required for their splicing. Truncated PBF6 containing the 10 N-terminal PPR motifs bound to specific sequences to ycf3 intron 1, clpP1 intron 2, and to the introns of petB, ndhA, and ndhB. PBF6 formed two multi-subunit splicing complexes with other known splicing factors from the CRM, peptidyl-tRNA hydrolase, RNase III, PORR, APO, DEAD-box RNA helicase, and mTERF families. PBF6-containing complex I was about 600 kDa, comprising nine known splicing factors: CAF1, CAF2, CRS2, CFM3a, RNC1, WTF1, APO2, RH3, and mTERF2. PBF6-containing complex II was about 300 kDa and contained three known splicing factors: CAF1, CAF2, and CFM2. Furthermore, two known PPR-type splicing factors, PBF2 and ECD2, both of which are required for splicing the ycf3 intron 1, also formed two multi-subunit splicing complexes with other known splicing factors. Importantly, these three PPR-type splicing factors formed their splicing complexes independently. Our data suggest that a PPR-type splicing factor forms splicing complexes with other known splicing factors under transient expression conditions to facilitate intron splicing and that several PPR-type splicing factors work together to promote the splicing of the same intron through forming respective splicing complexes.
Cytoplasmic male sterility (CMS) reduces pollen fertility and nuclear Rf genes restore fertility. This Commentary explores support for the "arms race" and "pre-adaptation" models for CMS-Rf co-evolution. CMS and Rf inter...Cytoplasmic male sterility (CMS) reduces pollen fertility and nuclear Rf genes restore fertility. This Commentary explores support for the "arms race" and "pre-adaptation" models for CMS-Rf co-evolution. CMS and Rf interact dynamically, influencing plant reproduction, stress tolerance, and hybrid seed production, highlighting co-evolutionary processes critical for crop improvement.
Symbiotic nitrogen fixation (SNF) is essential for legume productivity and sustainable agriculture, yet the genetic and regulatory bases of its natural variation remain incompletely understood. Here, we implemented an in...Symbiotic nitrogen fixation (SNF) is essential for legume productivity and sustainable agriculture, yet the genetic and regulatory bases of its natural variation remain incompletely understood. Here, we implemented an integrative multi-omics framework to dissect SNF architecture in a diversity panel of 360 soybean accessions encompassing both wild and cultivated lineages. SNF-related traits exhibited extensive variation and strong environmental sensitivity. Genome-wide association studies (GWAS) detected only modest-effect loci, consistent with a polygenic and context-dependent genetic architecture. To resolve regulatory mechanisms underlying this complexity, we analyzed population-scale mature nodule transcriptomes using independent component analysis (ICA), identifying 136 expression modules, of which 15 were significantly associated with SNF traits and enriched for circadian rhythm, lipid metabolism, and defense response pathways. Transcriptome-wide association studies (TWAS) identified 1,453,806, and 178 significant gene-trait associations for nitrogen fixation per plant (NFP), nodule weight (NW), and nitrogen fixation efficiency (NFE), respectively. Among these, 185 transcription factors were identified, 39% overlapping selective sweeps, suggesting evolutionary selection on transcriptional regulation. Expression quantitative trait locus (eQTL) mapping further uncovered 4,654 significant regulatory variants (1,241 cis-, 2,505 trans-, and 908 mixed), including 38 trans-regulatory hotspots collectively influencing ~2,400 genes, nearly half of which are located in domestication-diverged genome regions. Functional validation confirmed that the circadian regulator GmLHY acts as a negative modulator of nodulation, while Dt2, a developmental transcription factor, exerts pleiotropic effects on nodule biomass and fixation efficiency. To facilitate community access, we developed SoySNFdb, an open database integrating all information for SNF in soybean, featuring AI-assisted querying for interactive exploration of regulatory networks. Together, our results suggest that, within this population and experimental context, natural diversity in SNF is associated with regulatory and expression-level variation rather than major-effect coding variants. This integrative framework and accompanying resources establish a basis for system-level dissection and predictive improvement of nitrogen fixation efficiency in legumes.
Plant flavor diversity arises from genomic variation across species and cultivars, yet the mechanisms linking natural genomic variation to flavor-related phenotypes remain insufficiently integrated. Here, we systematical...Plant flavor diversity arises from genomic variation across species and cultivars, yet the mechanisms linking natural genomic variation to flavor-related phenotypes remain insufficiently integrated. Here, we systematically review how diverse forms of genomic variation reshape the biosynthesis, transport, and accumulation of flavor-related metabolites, thereby driving diversification in sweetness, acidity, bitterness, piquancy, astringency, and aroma. We further integrate evidence from genomics, transcriptomics, metabolomics, and functional validation to outline a mechanistic framework linking genomic variation to the molecular and metabolic basis of flavor phenotypes. We then examine how artificial intelligence-assisted breeding and precision gene editing can accelerate the identification of causal variants and enable targeted improvement of flavor-related traits. This framework establishes plant flavor as a mechanism-based target for plant improvement, with broad implications for quality, nutrition, and sustainability.
Calcium-dependent protein kinases (CDPKs) in plants play crucial roles in mediating responses to both biotic and abiotic stresses. However, the molecular mechanism through which CDPKs regulate antiviral immunity in plant...Calcium-dependent protein kinases (CDPKs) in plants play crucial roles in mediating responses to both biotic and abiotic stresses. However, the molecular mechanism through which CDPKs regulate antiviral immunity in plants remains largely elusive. In this study, we identified ZmCDPK7 as a key player in response to various stimuli. Lines overexpressing ZmCDPK7 exhibited enhanced resistance to maize chlorotic mottle virus (MCMV) infection, while ZmCDPK7 knock-out lines demonstrated increased sensitivity, indicating that ZmCDPK7 positively regulates maize immunity against MCMV. Furthermore, ZmCDPK7 interacts with ZmAPX1 and enhances its enzymatic activity by phosphorylating ZmAPX1 at Thr164, thereby reducing reactive oxygen species (ROS) production. The scaffold protein ZmRACK1 interacts with both ZmCDPK7 and ZmAPX1, facilitating the formation of a ternary complex that enhances ZmCDPK7-mediated ZmAPX1 enzymatic activity. Lines overexpressing ZmAPX1 also showed increased resistance to MCMV infection, while ZmAPX1 mutant lines (Zmapx1 MU1 and Zmapx1 MU2) exhibited increased sensitivity. Additionally, CRISPR/Cas9-mediated genome editing of ZmRACK1 in maize resulted in increased susceptibility to MCMV. To counteract plant defense, the MCMV protein P31 interacts with ZmCDPK7 and ZmRACK1, disrupting the interaction between ZmRACK1-ZmCDPK7 and ZmCDPK7-ZmAPX1, thereby blocking the ternary complex formation. Moreover, ZmCDPK7 is also implicated in defense against drought stress and corn stalk rot. Overall, our findings provide valuable insights into the molecular mechanisms by which the ZmRACK1-ZmCDPK7-ZmAPX1 module regulates plant immunity, identifying the potential new targets for the genetic control of maize viral diseases.
Soil salinization severely inhibits plant growth, necessitating adaptive changes in root system architecture to enhance stress resilience. Cytokinin signaling plays a key role in regulating root plasticity under salt str...Soil salinization severely inhibits plant growth, necessitating adaptive changes in root system architecture to enhance stress resilience. Cytokinin signaling plays a key role in regulating root plasticity under salt stress. Type-A response regulators, which lack DNA-binding domains, fine-tune cytokinin signaling through phosphorylation-dependent interactions or transcriptional repression. Although type-A response regulators are associated with stress adaptation, their specific mechanistic roles in salt tolerance remain unclear. Here, we identify PuRR9, a type-A response regulator in poplar, as a negative regulator of cytokinin signaling that enhances salt tolerance through a phosphorylation cascade (PuHK2-PuHP5-PuRR9). Salt stress promotes PuRR9 phosphorylation, strengthening its interaction with the transcriptional repressor PuZFP1. Phosphorylated PuRR9 recruits PuZFP1 to the promoter of PuIPT3, a key cytokinin biosynthesis gene, thereby suppressing its expression. This repression reduces cytokinin biosynthesis and promotes root growth under salt stress. We propose that the PuHK2-PuHP5-PuRR9-PuZFP1 module enhances salt tolerance by establishing a phosphorylation-dependent negative feedback loop within the cytokinin pathway. These findings reveal a novel mechanism by which a type-A response regulator modulates root system architecture and extend current understanding of cytokinin signaling.
MdEBF1, a negative regulator of ethylene signaling, promotes ubiquitination-mediated degradation of the jasmonate (JA) signaling repressor MdJAZ2 to release the key transcription factor MdMYC2 and initiate JA-enhanced di...MdEBF1, a negative regulator of ethylene signaling, promotes ubiquitination-mediated degradation of the jasmonate (JA) signaling repressor MdJAZ2 to release the key transcription factor MdMYC2 and initiate JA-enhanced disease resistance in apple, while JA-activated MdMYC2 upregulates MdEBF1 transcription, establishing a positive feedback loop that amplifies JA signaling.
This commentary reviews the discovery by Yuan et al. of a conserved susceptibility module where fungal Gas2 stabilizes host SnRK1β1A to suppress nuclear immunity in rice. It discusses the mechanism for broad-spectrum res...This commentary reviews the discovery by Yuan et al. of a conserved susceptibility module where fungal Gas2 stabilizes host SnRK1β1A to suppress nuclear immunity in rice. It discusses the mechanism for broad-spectrum resistance via genome editing and considers the essential balance between enhanced defense and associated agronomic trade-offs.
Strigolactones (SLs) are plant-specialized butenolide signaling molecules, recognized as endogenous plant hormones, that control plant development and environmental adaptation. In Arabidopsis (Arabidopsis thaliana), the...Strigolactones (SLs) are plant-specialized butenolide signaling molecules, recognized as endogenous plant hormones, that control plant development and environmental adaptation. In Arabidopsis (Arabidopsis thaliana), the repressor D53-like SMXLs regulate the expression of a vast number of genes in an EAR-motif-dependent manner to mediate SL signaling. However, it remains unclear how the SMXLs are recruited to specific genes and implement unique functions in vivo. Based on chromatin co-distribution analysis, we constructed a chromatin co-localization map of SMXL6 with 108 transcription factors. Among the candidate transcription factors, the Class II TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) family member TCP4 shows the highest frequency of chromatin co-localization with SMXL6. SMXL6 and TCP4 co‑localize at the promoter regions of 18 SL-induced SMXL6 target genes (SISGs), including BRC1. We confirmed that TCP4 interacts with SMXL6 and can bind directly to these co‑localized sites. The loss of CIN-TCPs function reduces the hormone responsiveness of the SL-induced genes. Introducing the tcp3/4/10 into SL‑deficient mutants restored the BRC1 expression to a level exceeding that of the wild type. However, the branching phenotype of the SL‑deficient mutant was only partially rescued, suggesting a limited role for BRC1 in SL‑mediated branching control and implicating the involvement of additional factors. An unexpected finding was that tcp3/4/10 rescued the dwarf phenotype of the SL‑deficient mutants, providing an opportunity to elucidate the mechanisms underlying SL‑regulated plant height. These findings demonstrate that TCP4 mediates SMXL6 chromatin recruitment during SL signaling, and provide a new understanding of how SMXL6 participates in SL signaling-mediated gene expression and plant development.
Phosphate starvation response (PHR) transcription factors are master regulators of the plant phosphate (Pi) starvation response (PSR), yet the mechanisms governing the dynamic control of their transcriptional activity re...Phosphate starvation response (PHR) transcription factors are master regulators of the plant phosphate (Pi) starvation response (PSR), yet the mechanisms governing the dynamic control of their transcriptional activity remain elusive. Here, we report a dual regulatory module comprising the coactivator SlMED25 and the corepressor SlSPX2 that fine-tunes SlPHR3 activity in Solanum lycopersicum (tomato). Genetic and biochemical evidence collectively confirmed that SlPHR3 acts as the central regulator orchestrating tomato PSR. Specifically, the mediator subunit SlMED25 interacts with the N-terminal domain (NTD) of SlPHR3 to recruit RNA polymerase II (Pol II) to SlPHR3 target promoters in a SlPHR3-dependent fashion, whereas SlSPX2 binds to the same NTD of SlPHR3 to robustly suppress its transcriptional activity. Biochemical assays further demonstrated that SlSPX2 and SlMED25 compete for binding to SlPHR3, with SlSPX2 exhibiting higher binding affinity. This competitive binding module functions as a key molecular switch that mediates dynamic PSR modulation in tomato, thus yielding distinct functional outputs in response to varying intracellular Pi levels. Our findings uncover a previously uncharacterized regulatory layer in the PSR network, wherein a Mediator subunit and a Pi-sensing protein modulate PHR activity via competitive binding, thereby enhancing the mechanistic insight into Pi homeostasis regulation in plants.
Walia Y, Noopur M, Bhattacharya I
… +10 more, Sahoo BC, Kasera M, Pullagurla NJ, Dutta S, Liu G, Schaaf G, Jessen H, Laha D, Bhattacharjee S, Bhattacharjee S
Plant Cullin RING Ubiquitin E3 ligases (CRLs) play a critical role in targeted protein degradation, essential for physiological development and stress adaptation. The deneddylase activity of the COP9 signalosome (CSN) ti...Plant Cullin RING Ubiquitin E3 ligases (CRLs) play a critical role in targeted protein degradation, essential for physiological development and stress adaptation. The deneddylase activity of the COP9 signalosome (CSN) tightly regulates the cellular balance of neddylated cullins, which is crucial for maintaining the full spectrum of CRL functions. Although selective inositol polyphosphates (InsPs) act as cofactors in plant responses that involve ubiquitylation of negative regulators, their connection to CSN-CRL activities has remained unclear. In this study, we reveal that the two Arabidopsis thaliana InsP-kinases, IPK1 and ITPK1, physically interact and orchestrate the metabolic regulation of the CSN holo-complex activity. Notably, ITPK1 deficiency lowers Nedd8 processing rates, elevates the cellular ratios of neddylated cullins, and disturbs the dissociation equilibrium of CSN5 and CUL1 from the holo-complex. These findings uncover a novel autoregulatory switch in CSN functions, governed by deneddylation activity. Furthermore, we demonstrate that the phosphate starvation response (PSR), induced in phosphate-limited wild-type plants and constitutively active in the InsP-kinase mutants, is partly regulated by reduced deneddylation rates, which affect the stability of SPX4, a key negative regulator of PSR. Pharmacological inhibition of cullin neddylation stabilizes SPX4 and impairs PSR, thereby linking CSN-CRL dynamics to phosphate sensing. Conversely, pharmacologically inhibiting CSN5 deneddylase activity causes wild-type plants to exhibit PSR phenotypes similar to those of the InsP-kinase mutants. Collectively, these results reveal that specific InsP-kinases are partly involved in modulating plant PSR by fine-tuning the coordination between CRL and CSN activities.
The eukaryotic chaperonin containing T-complex polypeptide-1 (CCT/TRiC) complex, composed of eight distinct subunits (CCT1-CCT8), is essential for cytosolic protein folding; however, its function in plants remains largel...The eukaryotic chaperonin containing T-complex polypeptide-1 (CCT/TRiC) complex, composed of eight distinct subunits (CCT1-CCT8), is essential for cytosolic protein folding; however, its function in plants remains largely unexplored. Moreover, a direct link between CCT and coat protein complex II (COPII) vesicle trafficking-a key step in the early secretory pathway-has not been established in any eukaryotic system. Here, leveraging plant genetics, we investigated the functional relationship between CCT8 and COPII-mediated trafficking in the Arabidopsis root apex. The point mutant cct8-1 exhibited a short-root phenotype resulting from impaired cell division in the root meristem, which was accompanied by disrupted auxin homeostasis. This defect stemmed from a marked reduction in the abundance of multiple PIN-FORMED (PIN) auxin efflux carriers at the plasma membrane, without affecting their polar localization. Mechanistically, CCT8 directly interacted with SEC31B, a core component of the COPII coat. Accordingly, the sec31b-3 mutant phenocopied cct8-1 in root growth, auxin response, and PIN accumulation defects. The CCT8 mutation reduced SEC31B abundance at both the transcriptional and protein levels and compromised ER-to-Golgi transport, thereby diminishing PIN delivery to the plasma membrane. Importantly, overexpression of SEC31B partially rescued the root growth defects and restored PIN2 levels in cct8-1. Together, our findings uncover a previously unrecognized chaperonin-trafficking module in which CCT8 regulates SEC31B to modulate COPII-mediated delivery of PIN proteins, thus linking chaperonin function to auxin-dependent root development.
Soybeans serve as excellent sources of vegetable oil, protein, and other valuable nutrients for human consumption, materials for diverse industries, including the cosmetics and medical industries, and feedstocks for anim...Soybeans serve as excellent sources of vegetable oil, protein, and other valuable nutrients for human consumption, materials for diverse industries, including the cosmetics and medical industries, and feedstocks for animals. Nevertheless, some people do not favor soy oil or other various food products derived from soybeans, due to inadequate levels of oleic acid in the oil and the presence of undesirable grassy and beany flavors associated with oxidation products of polyunsaturated fatty acids in the seeds. In this study, we developed soybean cultivars with very high levels of oleic acid in the seeds, and without grassy and beany flavors. We achieved this by using CRISPR-Cas-SF01 to edit genes in the elite cultivar Xudou 18 (XD18), targeting two microsomal Δ-12 fatty acid desaturase 2 (GmFAD2-1A and GmFAD2-1B) and three lipoxygenase (GmLOX1, GmLOX2, and GmLOX3) genes. Our findings showed that fad2-1a/b and fad2-1a/b/lox1/2/3 plants performed similarly to XD18 plants in the field, indicating no obvious growth penalties. Overall, this research has demonstrated that the development of soybean germplasms with high levels of oleic acid and without undesirable beany flavors through gene-editing of multiple relevant genes is effective, and this endeavor can contribute to the health of a broader global consumer population.
Citrus bacterial canker (CBC) is a globally important citrus disease caused by Xanthomonas citri subsp. citri (Xcc). Increasing evidence shows that the plant microbiome is crucial for host growth performance and health m...Citrus bacterial canker (CBC) is a globally important citrus disease caused by Xanthomonas citri subsp. citri (Xcc). Increasing evidence shows that the plant microbiome is crucial for host growth performance and health maintenance, among which the keystone taxa stand out due to their indispensable roles in microbiome homeostasis. However, how keystone taxa in the phyllosphere microbiome contribute to disease resistance remains unclear. In this study, we characterized the phyllosphere bacterial community of pomelo across an annual cycle and found that amino acids in leaves were the main drivers of the bacterial community structure. Meanwhile, five OTUs were identified as keystone taxa. A total of 587 phyllosphere bacterial strains were isolated, among which six strains belonging to Methylobacterium, Sphingomonas, Massilia, and Paenibacillus were identified as the corresponding keystone strains. We further constructed a consortium with these six strains to test its role in controlling CBC in planta. Network analysis reveals that consortium inoculation increased the phyllosphere bacterial community stability, whereas Xcc inoculation decreased it. However, dual inoculation of the consortium and Xcc restored community stability compared to the control. Interestingly, the inoculated keystone strains, if not all, still appeared as keystone taxa in the microbiomes of the control, consortium inoculation, and dual inoculation treatments, but not in the Xcc-inoculated treatment. Moreover, the consortium inoculation significantly increased the defense-related enzyme activities such as PPO, POD, and PAL in leaves, suggesting a triggered plant immune response. In vitro assays indicated that these keystone strains showed either antagonistic activity against Xcc or siderophore-producing activity. Finally, the consortium inoculation significantly reduced the disease index by 78% in planta. Taken together, these results suggest that the keystone taxa of the phyllosphere microbiome can confer disease resistance to the host via multiple mechanisms, especially by maintaining phyllosphere microbiome homeostasis.