CsLOB1 regulates susceptibility to citrus canker through promoting cell proliferation in citrus

Visible-light-driven water-soluble zinc oxide quantum dots for efficient control of citrus canker

BACKGROUND

Citrus canker caused by Xanthomonas citri subsp. citri (Xcc) is a devastating bacterial disease that reduces citrus yield and quality, posing a serious threat to the citrus industry. Several conventional chemicals have been used to control citrus canker. However, this approach often leads to the excessive use of chemical agents, can exacerbate environmental pollution and promotes the development of resistant Xcc. Therefore, there is significant interest in the development of efficient and environmentally friendly technologies to control citrus canker.

RESULTS

In this study, water-soluble ZnO quantum dots (ZnO QDs) were synthesised as an efficient nanopesticide against Xcc. The results showed that the antibacterial activity of ZnO QDs irradiated with visible light [half-maximal effective concentration (EC50) = 33.18 μg mL-1] was ~3.5 times higher than that of the dark-treated group (EC50 = 114.80 μg mL-1). ZnO QDs induced the generation of reactive oxygen species (•OH, •O- 2 and 1O2) under light irradiation, resulting in DNA damage, cytoplasmic destruction, and decreased catalase and superoxide dismutase activities. Transcription analysis showed downregulation of Xcc genes related to 'biofilms, virulence, adhesion' and 'DNA transfer' exposure to ZnO QDs. More importantly, ZnO QDs also promoted the growth of citrus.

CONCLUSION

This research provides new insights into the photocatalytic antibacterial mechanisms of ZnO QDs and supports the development of more efficient and safer ZnO QDs-based nanopesticides to control citrus canker. © 2024 Society of Chemical Industry.

Trans-crop applications of atypical R genes for multipathogen resistance

Genetic resistance to plant diseases is essential for global food security. Significant progress has been achieved for plant disease-resistance (R) genes comprising nucleotide-binding domain, leucine-rich repeat-containing receptors (NLRs), and membrane-localized receptor-like kinases or proteins (RLKs/RLPs), which we refer to as typical R genes. However, there is a knowledge gap in how non-receptor-type or atypical R genes contribute to plant immunity. Here, we summarize resources and technologies facilitating the study of atypical R genes, examine diverse atypical R proteins for broad-spectrum resistance, and outline potential approaches for trans-crop applications of atypical R genes. Studies of atypical R genes are important for a holistic understanding of plant immunity and the development of novel strategies in disease control and crop improvement.

Design and Synthesis of Mandelic Acid Derivatives for Suppression of Virulence via T3SS against Citrus Canker

Citrus canker, a highly contagious bacterial disease caused by Xanthomonas citri subsp. citri (Xcc), poses a substantial threat to citrus crops, leading to serious reductions in fruit yield and economic losses. Most commonly used bactericides against Xcc lead to the rapid development of resistant subpopulations. Therefore, it is imperative to create novel drugs, such as type III secretion system (T3SS) inhibitors, that specifically target bacterial virulence factors rather than bacterial viability. In our study, we designed and synthesized a series of mandelic acid derivatives including 2-mercapto-1,3,4-thiazole. Seven substances were found to reduce the level of transcription of hpa1 without affecting bacterial viability. In vivo bioassays indicated that compound F9 significantly inhibited hypersensitive response and pathogenicity. RT-qPCR assays showed that compound F9 visibly suppressed the expression of Xcc T3SS-related genes as well as citrus canker susceptibility gene CsLOB1. Furthermore, the combination with compound F9 and quorum-quenching bacteria HN-8 can also obviously alleviate canker symptoms.

Generation of transgene-free canker-resistant Citrus sinensis cv. Hamlin in the T0 generation through Cas12a/CBE co-editing

Citrus canker disease affects citrus production. This disease is caused by Xanthomonas citri subsp. citri (Xcc). Previous studies confirmed that during Xcc infection, PthA4, a transcriptional activator like effector (TALE), is translocated from the pathogen to host plant cells. PthA4 binds to the effector binding elements (EBEs) in the promoter region of canker susceptibility gene LOB1 (EBEPthA4-LOBP) to activate its expression and subsequently cause canker symptoms. Previously, the Cas12a/CBE co-editing method was employed to disrupt EBEPthA4-LOBP of pummelo, which is highly homozygous. However, most commercial citrus cultivars are heterozygous hybrids and more difficult to generate homozygous/biallelic mutants. Here, we employed Cas12a/CBE co-editing method to edit EBEPthA4-LOBP of Hamlin (Citrus sinensis), a commercial heterozygous hybrid citrus cultivar grown worldwide. Binary vector GFP-p1380N-ttLbCas12a:LOBP1-mPBE:ALS2:ALS1 was constructed and shown to be functional via Xcc-facilitated agroinfiltration in Hamlin leaves. This construct allows the selection of transgene-free regenerants via GFP, edits ALS to generate chlorsulfuron-resistant regenerants as a selection marker for genome editing resulting from transient expression of the T-DNA via nCas9-mPBE:ALS2:ALS1, and edits gene(s) of interest (i.e., EBEPthA4-LOBP in this study) through ttLbCas12a, thus creating transgene-free citrus. Totally, 77 plantlets were produced. Among them, 8 plantlets were transgenic plants (#HamGFP1 - #HamGFP8), 4 plantlets were transgene-free (#HamNoGFP1 - #HamNoGFP4), and the rest were wild type. Among 4 transgene-free plantlets, three lines (#HamNoGFP1, #HamNoGFP2 and #HamNoGFP3) contained biallelic mutations in EBEpthA4, and one line (#HamNoGFP4) had homozygous mutations in EBEpthA4. We achieved 5.2% transgene-free homozygous/biallelic mutation efficiency for EBEPthA4-LOBP in C. sinensis cv. Hamlin, compared to 1.9% mutation efficiency for pummelo in a previous study. Importantly, the four transgene-free plantlets and 3 transgenic plantlets that survived were resistant against citrus canker. Taken together, Cas12a/CBE co-editing method has been successfully used to generate transgene-free canker-resistant C. sinensis cv. Hamlin in the T0 generation via biallelic/homozygous editing of EBEpthA4 of the canker susceptibility gene LOB1.

Genome editing for healthy crops: traits, tools and impacts

Crop cultivars in commercial use have often been selected because they show high levels of resistance to pathogens. However, widespread cultivation of these crops for many years in the environments favorable to a pathogen requires durable forms of resistance to maintain "healthy crops". Breeding of new varieties tolerant/resistant to biotic stresses by incorporating genetic components related to durable resistance, developing new breeding methods and new active molecules, and improving the Integrated Pest Management strategies have been of great value, but their effectiveness is being challenged by the newly emerging diseases and the rapid change of pathogens due to climatic changes. Genome editing has provided new tools and methods to characterize defense-related genes in crops and improve crop resilience to disease pathogens providing improved food security and future sustainable agricultural systems. In this review, we discuss the principal traits, tools and impacts of utilizing genome editing techniques for achieving of durable resilience and a "healthy plants" concept.

Comparative transcriptome analysis reveals key pathways and regulatory networks in early resistance of Glycine max to soybean mosaic virus

As a high-value oilseed crop, soybean [Glycine max (L.) Merr.] is limited by various biotic stresses during its growth and development. Soybean mosaic virus (SMV) is a devastating viral infection of soybean that primarily affects young leaves and causes significant production and economic losses; however, the synergistic molecular mechanisms underlying the soybean response to SMV are largely unknown. Therefore, we performed RNA sequencing on SMV-infected resistant and susceptible soybean lines to determine the molecular mechanism of resistance to SMV. When the clean reads were aligned to the G. max reference genome, a total of 36,260 genes were identified as expressed genes and used for further research. Most of the differentially expressed genes (DEGs) associated with resistance were found to be enriched in plant hormone signal transduction and circadian rhythm according to Kyoto Encyclopedia of Genes and Genomes analysis. In addition to salicylic acid and jasmonic acid, which are well known in plant disease resistance, abscisic acid, indole-3-acetic acid, and cytokinin are also involved in the immune response to SMV in soybean. Most of the Ca2+ signaling related DEGs enriched in plant-pathogen interaction negatively influence SMV resistance. Furthermore, the MAPK cascade was involved in either resistant or susceptible responses to SMV, depending on different downstream proteins. The phytochrome interacting factor-cryptochrome-R protein module and the MEKK3/MKK9/MPK7-WRKY33-CML/CDPK module were found to play essential roles in soybean response to SMV based on protein-protein interaction prediction. Our findings provide general insights into the molecular regulatory networks associated with soybean response to SMV and have the potential to improve legume resistance to viral infection.

'Candidatus Liberibacter asiaticus' secretory protein SDE3 inhibits host autophagy to promote Huanglongbing disease in citrus

Antimicrobial acroautophagy/autophagy plays a vital role in degrading intracellular pathogens or microbial molecules in host-microbe interactions. However, microbes evolved various mechanisms to hijack or modulate autophagy to escape elimination. Vector-transmitted phloem-limited bacteria, Candidatus Liberibacter (Ca. Liberibacter) species, cause Huanglongbing (HLB), one of the most catastrophic citrus diseases worldwide, yet contributions of autophagy to HLB disease proliferation remain poorly defined. Here, we report the identification of a virulence effector in "Ca. Liberibacter asiaticus" (Las), SDE3, which is highly conserved among the "Ca. Liberibacter". SDE3 expression not only promotes the disease development of HLB and canker in sweet orange (Citrus sinensis) plants but also facilitates Phytophthora and viral infections in Arabidopsis, and Nicotiana benthamiana (N. benthamiana). SDE3 directly associates with citrus cytosolic glyceraldehyde-3-phosphate dehydrogenases (CsGAPCs), which negatively regulates plant immunity. Overexpression of CsGAPCs and SDE3 significantly inhibits autophagy in citrus, Arabidopsis, and N. benthamiana. Intriguingly, SDE3 undermines autophagy-mediated immunity by the specific degradation of CsATG8 family proteins in a CsGAPC1-dependent manner. CsATG8 degradation is largely rescued by treatment with an inhibitor of the late autophagic pathway, E64d. Furthermore, ectopic expression of CsATG8s enhances Phytophthora resistance. Collectively, these results suggest that SDE3-CsGAPC interactions modulate CsATG8-mediated autophagy to enhance Las progression in citrus.Abbreviations: ACP: asian citrus psyllid; ACD2: ACCELERATED CELL DEATH 2; ATG: autophagy related; Ca. Liberibacter: Candidatus Liberibacter; CaMV: cauliflower mosaic virus; CMV: cucumber mosaic virus; Cs: Citrus sinensis; EV: empty vector; GAPC: cytosolic glyceraldehyde-3-phosphate dehydrogenase; HLB: huanglongbing; H2O2: hydrogen peroxide; Las: liberibacter asiaticus; Laf: liberibacter africanus; Lam: liberibacter americanus; Pst: Pseudomonas syringae pv. tomato; PVX: potato virus X; ROS: reactive oxygen species; SDE3: sec-delivered effector 3; TEM: transmission electron microscopy; VIVE : virus-induced virulence effector; WT: wild-type; Xcc: Xanthomonas citri subsp. citri.

Promoter characterization of a citrus linalool synthase gene mediating interspecific variation in resistance to a bacterial pathogen

BACKGROUND

Terpenoids play essential roles in plant defense against biotic stresses. In Citrus species, the monoterpene linalool mediates resistance against citrus canker disease caused by the gram-negative bacteria Xanthomonas citri subsp. citri (Xcc). Previous work had associated linalool contents with resistance; here we characterize transcriptional responses of linalool synthase genes.

RESULTS

Leaf linalool contents are highly variable among different Citrus species. "Dongfang" tangerine (Citrus reticulata), a species with high linalool levels was more resistant to Xcc than "Shatian" pummelo (C. grandis) which accumulates only small amounts of linalool. The coding sequences of the major leaf-expressed linalool synthase gene (STS4) are highly conserved, while transcript levels differ between the two Citrus species. To understand this apparent differential transcription, we isolated the promoters of STS4 from the two species, fused them to a GUS reporter and expressed them in Arabidopsis. This reporter system revealed that the two promoters have different constitutive activities, mainly in trichomes. Interestingly, both linalool contents and STS4 transcript levels are insensitive to Xcc infestation in citrus plants, but in these transgenic Arabidopsis plants, the promoters are activated by challenge of a bacterial pathogen Pseudomonas syringae, as well as wounding and external jasmonic acid treatment.

CONCLUSIONS

Our study reveals variation in linalool and resistance to Xcc in citrus plants, which may be mediated by different promoter activities of a terpene synthase gene in different Citrus species.

Generation of the transgene-free canker-resistant Citrus sinensis using Cas12a/crRNA ribonucleoprotein in the T0 generation

Citrus canker caused by Xanthomonas citri subsp. citri (Xcc) is a destructive citrus disease worldwide. Generating disease-resistant cultivars is the most effective, environmentally friendly and economic approach for disease control. However, citrus traditional breeding is lengthy and laborious. Here, we develop transgene-free canker-resistant Citrus sinensis lines in the T0 generation within 10 months through transformation of embryogenic protoplasts with Cas12a/crRNA ribonucleoprotein to edit the canker susceptibility gene CsLOB1. Among the 39 regenerated lines, 38 are biallelic/homozygous mutants, demonstrating a 97.4% biallelic/homozygous mutation rate. No off-target mutations are detected in the edited lines. Canker resistance of the cslob1-edited lines results from both abolishing canker symptoms and inhibiting Xcc growth. The transgene-free canker-resistant C. sinensis lines have received regulatory approval by USDA APHIS and are exempted from EPA regulation. This study provides a sustainable and efficient citrus canker control solution and presents an efficient transgene-free genome-editing strategy for citrus and other crops.

The Expansin Gene CsLIEXP1 Is a Direct Target of CsLOB1 in Citrus

Transcription activator-like effectors are key virulence factors of Xanthomonas. They are secreted into host plant cells and mimic transcription factors inducing the expression of host susceptibility (S) genes. In citrus, CsLOB1 is a direct target of PthA4, the primary effector associated with citrus canker symptoms. CsLOB1 is a transcription factor, and its expression is required for canker symptoms induced by Xanthomonas citri subsp. citri. Several genes are up-regulated by PthA4; however, only CsLOB1 was described as an S gene induced by PthA4. Here, we investigated whether other up-regulated genes could be direct targets of PthA4 or CsLOB1. Seven up-regulated genes by PthA4 were investigated; however, an expansin-coding gene was more induced than CsLOB1. In Nicotiana benthamiana transient expression experiments, we demonstrate that the expansin-coding gene, referred here to as CsLOB1-INDUCED EXPANSIN 1 (CsLIEXP1), is not a direct target of PthA4, but CsLOB1. Interestingly, CsLIEXP1 was induced by CsLOB1 even without the predicted CsLOB1 binding site, which suggested that CsLOB1 has other unknown binding sites. We also investigated the minimum promoter regulated by CsLOB1, and this region and LOB1 domain were conserved among citrus species and relatives, which suggests that the interaction PthA4-CsLOB1-CsLIEXP1 is conserved in citrus species and relatives. This is the first study that experimentally demonstrated a CsLOB1 downstream target and lays the foundation to identify other new targets. In addition, we demonstrated that the CsLIEXP1 is a putative S gene indirectly induced by PthA4, which may serve as the target for genome editing to generate citrus canker-resistant varieties.

Applications of CRISPR/Cas genome editing in economically important fruit crops: recent advances and future directions

Fruit crops, consist of climacteric and non-climacteric fruits, are the major sources of nutrients and fiber for human diet. Since 2013, CRISPR/Cas (Clustered Regularly Interspersed Short Palindromic Repeats and CRISPR-Associated Protein) genome editing system has been widely employed in different plants, leading to unprecedented progress in the genetic improvement of many agronomically important fruit crops. Here, we summarize latest advancements in CRISPR/Cas genome editing of fruit crops, including efforts to decipher the mechanisms behind plant development and plant immunity, We also highlight the potential challenges and improvements in the application of genome editing tools to fruit crops, including optimizing the expression of CRISPR/Cas cassette, improving the delivery efficiency of CRISPR/Cas reagents, increasing the specificity of genome editing, and optimizing the transformation and regeneration system. In addition, we propose the perspectives on the application of genome editing in crop breeding especially in fruit crops and highlight the potential challenges. It is worth noting that efforts to manipulate fruit crops with genome editing systems are urgently needed for fruit crops breeding and demonstration.

A chromosome-level phased genome enabling allele-level studies in sweet orange: a case study on citrus Huanglongbing tolerance

Sweet orange originated from the introgressive hybridizations of pummelo and mandarin resulting in a highly heterozygous genome. How alleles from the two species cooperate in shaping sweet orange phenotypes under distinct circumstances is unknown. Here, we assembled a chromosome-level phased diploid Valencia sweet orange (DVS) genome with over 99.999% base accuracy and 99.2% gene annotation BUSCO completeness. DVS enables allele-level studies for sweet orange and other hybrids between pummelo and mandarin. We first configured an allele-aware transcriptomic profiling pipeline and applied it to 740 sweet orange transcriptomes. On average, 32.5% of genes have a significantly biased allelic expression in the transcriptomes. Different cultivars, transgenic lineages, tissues, development stages, and disease status all impacted allelic expressions and resulted in diversified allelic expression patterns in sweet orange, but particularly citrus Huanglongbing (HLB) shifted the allelic expression of hundreds of genes in leaves and calyx abscission zones. In addition, we detected allelic structural mutations in an HLB-tolerant mutant (T19) and a more sensitive mutant (T78) through long-read sequencing. The irradiation-induced structural mutations mostly involved double-strand breaks, while most spontaneous structural mutations were transposon insertions. In the mutants, most genes with significant allelic expression ratio alterations (≥1.5-fold) were directly affected by those structural mutations. In T19, alleles located at a translocated segment terminal were upregulated, including CsDnaJ, CsHSP17.4B, and CsCEBPZ. Their upregulation is inferred to keep phloem protein homeostasis under the stress from HLB and enable subsequent stress responses observed in T19. DVS will advance allelic level studies in citrus.

A "Candidatus Liberibacter asiaticus"-secreted polypeptide suppresses plant immune responses in Nicotiana benthamiana and Citrus sinensis

Citrus Huanglongbing (HLB), known as the most economically devastating disease in citrus industry, is mainly caused by phloem-restricted Gram-negative bacterium "Candidatus Liberibacter asiaticus" (CLas). To date, CLas is still unculturable in vitro, which has been dramatically delaying the research on its pathogenesis, and only few Sec-dependent effectors (SDEs) have been identified to elucidate the pathogenesis of CLas. Here, we confirmed that a CLas-secreted Sec-dependent polypeptide, namely SECP8 (CLIBASIA_05330), localized in nucleus, cytoplasm and cytoplasmic membrane, and showed remarkably higher transcript abundance in citrus than in psyllids. Potato virus X (PVX)-mediated transient expression assays indicated that mSECP8 (the mature form of SECP8) suppressed pro-apoptotic mouse protein BAX and Phytophthora infestans elicitin INF1-triggered hypersensitive response (HR) associated phenotypes, including cell death, H2O2 accumulation and callose deposition. Intriguingly, mSECP8 also inhibited SDE1 (CLIBASIA_05315)-induced water-soaked and dwarfing symptoms in Nicotiana benthamiana. In addition, mSECP8 can promote the susceptibility of transgenic Wanjincheng orange (Citrus sinensis) to CLas invasion and further HLB symptom development, and it contributes to the proliferation of Xanthomonas citri subsp. citri (Xcc). Moreover, the expression of ten immunity-related genes were significantly down-regulated in mSECP8 transgenic citrus than those in wide-type (WT) plants. Overall, we propose that mSECP8 may serve as a novel broad-spectrum suppressor of plant immunity, and provide the first evidence counteractive effect among CLas effectors. This study will enrich and provide new evidences for elucidating the pathogenic mechanisms of CLas in citrus host.

Group IIc WRKY transcription factors regulate cotton resistance to Fusarium oxysporum by promoting GhMKK2-mediated flavonoid biosynthesis

WRKY transcription factors (TFs) are crucial regulators in response to pathogen infection. However, the regulatory mechanisms of WRKY TFs in response to Fusarium oxysporum f. sp. vasinfectum (Fov), the most devastating pathogen of cotton, remain unclear. Here, transcriptome sequencing indicated that the group IIc WRKY TF subfamily was the most important TF subfamily in response to Fov. Gain-of-function and loss-of-function analyses showed that group IIc WRKY TFs positively regulated cotton resistance to Fov. A series of chromatin immunoprecipitation sequencing, yeast one-hybrid assay and electrophoresis mobility shift assay experiments indicated that group IIc WRKY TFs directly bound to the promoter of GhMKK2 and regulated its expression. Importantly, a novel mitogen-activated protein kinase (MAPK) cascade composed of GhMKK2, GhNTF6 and GhMYC2 was identified. The functional analysis indicated that group IIc WRKY TFs induced the GhMKK2-GhNTF6 pathway to increase resistance to Fov by upregulating the GhMYC2-mediated expression of several flavonoid biosynthesis-related genes, which led to flavonoid accumulation. In conclusion, our study demonstrated a novel disease defense mechanism by which the WRKY-MAPK pathway promotes flavonoid biosynthesis to defend against pathogen infection. This pathway improves our understanding of the interaction mode between WRKY TFs and MAPK cascades in plant immunity and the vital role of plant flavonoids in pathogen defense.

Molecular basis for host responses to Xanthomonas infection

This review highlights the most relevant and recent updated information available on the defense responses of selected hosts against Xanthomonas spp. Xanthomonas is one of the most important genera of Gram-negative phytopathogenic bacteria, severely affecting the productivity of economically important crops worldwide, colonizing either the vascular system or the mesophyll tissue of the host. Due to its rapid propagation, Xanthomonas poses an enormous challenge to farmers, because it is usually controlled using huge quantities of copper-based chemicals, adversely impacting the environment. Thus, developing new ways of preventing colonization by these bacteria has become essential. Advances in genomic and transcriptomic technologies have significantly elucidated at molecular level interactions between various crops and Xanthomonas species. Understanding how these hosts respond to the infection is crucial if we are to exploit potential approaches for improving crop breeding and cutting productivity losses. This review focuses on our current knowledge of the defense response mechanisms in agricultural crops after Xanthomonas infection. We describe the molecular basis of host-bacterium interactions over a broad spectrum with the aim of improving our fundamental understanding of which genes are involved and how they work in this interaction, providing information that can help to speed up plant breeding programs, namely using gene editing approaches.

Transcriptional regulation of fleshy fruit texture

Fleshy fruit texture is a critically important quality characteristic of ripe fruit. Softening is an irreversible process which operates in most fleshy fruits during ripening which, together with changes in color and taste, contributes to improvements in mouthfeel and general attractiveness. Softening results mainly from the expression of genes encoding enzymes responsible for cell wall modifications but starch degradation and high levels of flavonoids can also contribute to texture change. Some fleshy fruit undergo lignification during development and post-harvest, which negatively affects eating quality. Excessive softening can also lead to physical damage and infection, particularly during transport and storage which causes severe supply chain losses. Many transcription factors (TFs) that regulate fruit texture by controlling the expression of genes involved in cell wall and starch metabolism have been characterized. Some TFs directly regulate cell wall targets, while others act as part of a broader regulatory program governing several aspects of the ripening process. In this review, we focus on advances in our understanding of the transcriptional regulatory mechanisms governing fruit textural change during fruit development, ripening and post-harvest. Potential targets for breeding and future research directions for the control of texture and quality improvement are discussed.

TCP Transcription Factors Involved in Shoot Development of Ma Bamboo (Dendrocalamus latiflorus Munro)

Ma bamboo (Dendrocalamus latiflorus Munro) is the most widely cultivated clumping bamboo in Southern China and is valuable for both consumption and wood production. The development of bamboo shoots involving the occurrence of lateral buds is unique, and it affects both shoot yield and the resulting timber. Plant-specific TCP transcription factors are involved in plant growth and development, particularly in lateral bud outgrowth and morphogenesis. However, the comprehensive information of the TCP genes in Ma bamboo remains poorly understood. In this study, 66 TCP transcription factors were identified in Ma bamboo at the genome-wide level. Members of the same subfamily had conservative gene structures and conserved motifs. The collinear analysis demonstrated that segmental duplication occurred widely in the TCP transcription factors of Ma bamboo, which mainly led to the expansion of a gene family. Cis-acting elements related to growth and development and stress response were found in the promoter regions of DlTCPs. Expression patterns revealed that DlTCPs have tissue expression specificity, which is usually highly expressed in shoots and leaves. Subcellular localization and transcriptional self-activation experiments demonstrated that the five candidate TCP proteins were typical self-activating nuclear-localized transcription factors. Additionally, the transcriptome analysis of the bamboo shoot buds at different developmental stages helped to clarify the underlying functions of the TCP members during the growth of bamboo shoots. DlTCP12-C, significantly downregulated as the bamboo shoots developed, was selected to further verify its molecular function in Arabidopsis. The DlTCP12-C overexpressing lines exhibited a marked reduction in the number of rosettes and branches compared with the wild type in Arabidopsis, suggesting that DlTCP12-C conservatively inhibits lateral bud outgrowth and branching in plants. This study provides useful insights into the evolutionary patterns and molecular functions of the TCP transcription factors in Ma bamboo and provides a valuable reference for further research on the regulatory mechanism of bamboo shoot development and lateral bud growth.