Search Results (16)

NAC (NAM, ATAF1/2, CUC1/2) is a plant-specific transcription factor (TF) family that plays important roles in various physiological and biochemical processes of plants. However, the NAC gene family in Lagerstroemia indica and its role in anthocyanin metabolism are still unexplored. In our study, a total of 167 NACs were identified in the L. indica genome via genome-wide analysis and bioinformatics techniques. Amino acid sequence analysis showed that all 167 NAC proteins contained a conserved NAM domain. This domain primarily comprised random coils, extended strands, and alpha helices. Most NACs were found on the nucleus and dispersed over 23 of the 24 plant chromosomes. Based on phylogenetic analysis, the NACs can be categorized into ten subgroups. Furthermore, the promoter homeotropic elements predicted the cis-acting elements in the promoters of these genes related to hormones, development, environmental stress response, and other related responses, demonstrating the diverse regulatory mechanisms underlying gene functions. In addition, a co-expression network was established through RNA sequencing. This network helped identify seven key LiNACs, genes related to anthocyanin expression (CHS) and transcription factors (MYB and bHLH). To identify potential anthocyanin regulatory factors present in L. indica petals, protein interaction prediction was performed, which revealed that LiNACs might participate in anthocyanin regulation by interacting with other proteins, such as MYB, ABF, ABI, bZIP, MYC, etc. Our results provided novel insights and could help in the functional identification of LiNACs in L. indica and the regulation of anthocyanin synthesis. Full article

This study explored the bioactive lipid compounds and assessed the nutritional potential of glyceride oils extracted from flower buds and fruits of Lagerstroemia indica L. cultivar ‘Hopi’ grown in Bulgaria. The study focused on chemical composition, fatty acid composition, and the content of biologically active compounds of the oils. The results indicated relatively higher levels of glyceride oil in fruits (F), 14.8%, compared to flower buds (FB), 3.3%. A similar trend was observed for protein content—15.7% (F) vs. 8.7% (FB). Total sterol and phospholipid content was higher in the FB than in the F. The primary components of sterol composition were β-sitosterol and campesterol. The main individual phospholipid classes were phosphatidylinositol and phosphatidylcholine in both oils. Linoleic acid was the predominant component (77.3% in the oil from the FB vs. 86.0% in the oil from the F), followed by comparable quantities of oleic acid. Palmitic acid was the main saturated fatty acid. To evaluate the therapeutic effect of isolated glyceride oils, the following indices were measured: index of atherogenicity, thrombogenicity, and hypocholesterolemic/hypercholesterolemic ratio. The study sought to compare the levels of glyceride oil, protein content, total sterol and phospholipid content, and to identify the main components of fatty acids, sterols, and phospholipids in the flower buds and fruits and their oils of L. indica cultivar ‘Hopi’. Full article

Crape myrtle (Lagerstroemia indica and its relatives) is an important summer-flowering plant in numerous countries worldwide. However, there are few reports on salt-tolerant (ST) crape myrtle germplasm resources and their morphological and molecular biological foundations for adaptation to salinized soil, one of the main abiotic stresses in plants. This study identified the salt tolerance characteristics of 19 crape myrtle varieties and created four salt-tolerant germplasms through hybridization. Morphological anatomy and transcriptome analyses clarified that the xylem of the ST variety possessed a high number of vessels with a small lumen. Transcriptome research has indicated that under salt stress conditions, Ca²⁺, abscisic acid (ABA), and reactive oxygen species (ROS) pathways are involved in salt stress responses. One of the candidate genes LiTIP1;1 (encoding a tonoplast intrinsic protein) was overexpressed in Arabidopsis and the resultant overexpression (OE) lines performed better under CK and 100 mmol∙L⁻¹ NaCl salt stress, but not under 200 mmol∙L⁻¹ NaCl salt stress. Corresponding to physiological traits, genes encoding tubulin and fasciclin-like arabinogalactan proteins (FLAs), which are related to the plasma membrane localization of the cellulose synthase complex, are maintained at higher levels and are induced more by salt. In summary, this research has revealed the morphological, physiological, and molecular bases of ST crape myrtle to a certain extent and has provided a theoretical basis for further screening and breeding of salt-tolerant crape myrtle varieties. Full article

Lagerstroemia indica is a widely used ornamental woody plant known for its summer flowering and significant ornamental and economic value. While L. indica boasts a variety of rich flower colors, the molecular mechanisms underlying this color formation remain unclear. In this study, we selected three different flower colors of L. indica—white (W), red (R), and purple (P)—for transcriptome and metabolome analysis. The metabolome analysis identified 538 flavonoids, with 22 anthocyanins highly accumulated in the red and purple flowers. RNA-seq analysis annotated a total of 35,505 genes. Furthermore, we identified 42 differentially expressed genes (DEGs) involved in anthocyanin biosynthesis, with their expression levels aligning with anthocyanin content. Correlation analysis revealed that 19 MYB and 11 bHLH transcription factors are likely involved in anthocyanin biosynthesis. Additionally, we identified 59 auxin biosynthesis and signaling-related genes that are positively correlated with anthocyanin-related genes and metabolites, suggesting that auxin may play a role in regulating anthocyanin biosynthesis in L. indica. This study provides valuable insights into the regulatory mechanisms underlying anthocyanin accumulation and color formation in L. indica petals and identifies several potential genes, laying the groundwork for further research on regulatory mechanisms and genetic improvement of L. indica. Full article

Male sterility is a common phenomenon in higher plants and often plays an important role in the selection of superior offspring. ‘Xiang Yun’ is a mutant of Lagerstroemia indica that does not bear fruit after flowering, and its flowering period is significantly longer than that of normal L. indica. To explore the timing and molecular mechanisms of sterility in ‘Xiang Yun’, this study determined the period of sterility through anatomical observation and compared the content of nutrients and the activity of antioxidative enzymes at different stages of flower development. Finally, sequence alignment and qPCR were used to analyze the differences in pollen development genes between ‘Xiang Yun’ and ‘Hong Ye’. The results showed that the anthers of ‘Xiang Yun’ dispersed pollen normally, but the pollen grains could not germinate normally. Observations with scanning electron microscopy revealed that the pollen grains were uneven in size and shriveled in shape. Further observation of anther sections found that abnormal development of the microspores began at the S2 stage, with the callose wall between microspores of ‘Xiang Yun’ being thicker than that of ‘Hong Ye’. In addition, during the flower development of ‘Xiang Yun’, the contents of soluble sugar, soluble protein, free proline, and triglycerides were deficient to varying degrees, and the activities of POD, SOD, and MDA were lower. Sequence alignment and qPCR showed that there were several mutations in EFD1, TPD1, and DEX1 of ‘Xiang Yun’ compared with ‘Hong Ye’, and the expression levels of these genes were abnormally elevated in the later stages of development. Our results clarified the timing and phenotype of male sterility in ‘Xiang Yun’. This provides solid and valuable information for further research on the molecular mechanism of sterility in ‘Xiang Yun’ and the genetic breeding of crape myrtle. Full article

Weed control in cutting propagation is limited to manual hand weeding, which is time-consuming and labor-intensive. Preemergence herbicides and mulches may be viable weed control methods for cutting propagation, but crop safety and weed control efficacy must be better understood. Four preemergence herbicides (indaziflam, isoxaben, isoxaben + dithiopyr, and oxyfluorfen + oxadiazon) and two mulches (pine pellets and rice hulls) were assessed in cutting propagation for their impact on rooting and subsequent liner growth (butterfly bush [Buddleja davidii Franch.] and crape myrtle [Lagerstroemia indica L.]) and control of four common weed species. Butterfly bush cuttings had lower rooting percentage and root dry weight with isoxaben and isoxaben + dithiopyr, but no damage was observed for all other treatments during propagation or after transplant. Crape myrtle cutting root development and liner growth were statistically similar for all treatments compared to the non-treated control. Isoxaben, isoxaben + dithiopyr, oxyfluorfen + oxadiazon, and pine pellets provided excellent control (87 to 100%) of all four weed species tested. Overall, several preemergence herbicides and mulches were safe for use in cutting propagation and effective weed control varied by product and weed species. Full article

MADS-box is a key transcription factor regulating the transition to flowering and flower development. Lagerstroemia indica ‘Xiang Yun’ is a new cultivar of crape myrtle characterized by its non-fruiting nature. To study the molecular mechanism underlying the non-fruiting characteristics of ‘Xiang Yun’, 82 MADS-box genes were identified from the genome of L. indica. The physicochemical properties of these genes were examined using bioinformatics methods, and their expression as well as endogenous hormone levels at various stages of flower development were analyzed. The results showed that LiMADS genes were primarily classified into two types: type I and type II, with the majority being type II that contained an abundance of cis-acting elements in their promoters. By screening nine core proteins by predicted protein interactions and performing qRT-PCR analysis as well as in combination with transcriptome data, we found that the expression levels of most MADS genes involved in flower development were significantly lower in ‘Xiang Yun’ than in the wild type ‘Hong Ye’. Hormonal analysis indicated that ‘Xiang Yun’ had higher levels of iP, IPR, TZR, and zeatin during its early stages of flower development than ‘Hong Ye’, whereas the MeJA content was substantially lower at the late stage of flower development of ‘Hong Ye’. Finally, correlation analysis showed that JA, IAA, SA, and TZR were positively correlated with the expression levels of most type II genes. Based on these analyses, a working model for the non-fruiting ‘Xiang Yun’ was proposed. During the course of flower development, plant hormone response pathways may affect the expression of MADS genes, resulting in their low expression in flower development, which led to the abnormal development of the stamen and embryo sac and ultimately affected the fruiting process of ‘Xiang Yun’. Full article

Background: The yellow-leaf gl1 mutant of Lagerstroemia indica exhibits an altered phenylpropanoid metabolism pathway compared to wild-type (WT). However, details on the metabolites associated with leaf color variation, including color-specific metabolites with bioactive constituents, are not fully understood. Methods: Chemical and metabolomics approaches were used to compare metabolite composition and antioxidant capacity between the gl1 mutant and WT leaves. Results: The mutant exhibited an irregular xylem structure with a significantly lower phenolic polymer lignin content and higher soluble phenolic compounds. Untargeted metabolomics analysis identified phenolic compounds, particularly lignans, as key differential metabolites between gl1 and WT, with a significant increase in the mutant. The neolignan derivative balanophonin-4-O-D-glu was identified as a characteristic metabolite in the gl1 mutant. The soluble phenolic compounds of the gl1 mutant exhibited higher FRAP, ABTS, DPPH, and hydroxyl radical scavenging activity than in WT. Correlation analysis showed a positive relationship between antioxidant capacity and phenolic compounds in L. indica. Conclusions: Metabolites associated with leaf color variation in the L. indica yellow-leaf gl1 mutant demonstrated high antioxidant capacity, particularly in scavenging hydroxyl radicals. Full article

Lagerstroemia indica is an important woody ornamental plant worldwide. However, the application of many technologies, such as transgenic breeding and genome editing, has been severely hampered due to the lack of efficient calli induction and regeneration technology. Here, we discussed a reliable and efficient calli induction and regeneration protocol using whole-leaf explants. This protocol’s effectiveness for the calli induction and regeneration systems in crape myrtle were up to 70.33% and 44.33%, respectively. Next, an efficient and stable Agrobacterium-mediated genetic transformation system was created from leaf calli, and the green fluorescent protein (GFP) was able to detect up to 90% of its positive frequency. Meanwhile, two positive lines’ transfer DNA insertion sites and directions were identified using whole genome sequencing. LiMYB75, a novel R2R3-MYB transcription factor, was identified and transferred to the L. indica genome to enhance the leaf calli regeneration frequency. Surprisingly, overexpressing LiMYB75 increased the frequency of calli regeneration in the leaf by 1.27 times and the number of regenerated plantlets per callus by 4.00 times compared to the wild type, by regulating the expression levels of genes involved in callus formation, such as SHOOT MERISTEMLESS (STM). Overall, our findings revealed a simple, reliable, and highly efficient transformation approach and identified the desirable candidate gene LiMYB75, which improves L. indica’s calli regeneration efficiency. Full article

Lagerstroemia indica L. is a well-known ornamental plant with large pyramidal racemes, long flower duration, and diverse colors and cultivars. It has been cultivated for nearly 1600 years and is essential for investigating the germplasm and assessing genetic variation to support international cultivar identification and breeding programs. In this study, 20 common Lagerstroemia indica cultivars from different varietal groups and flower morphologies, as well as multiple wild relative species, were analyzed to investigate the maternal donor of Lagerstroemia indica cultivars and to discover the genetic variation and relationships among cultivars based on plastome and nuclear ribosomal DNA (nrDNA) sequences. A total of 47 single nucleotide polymorphisms (SNPs) and 24 insertion/deletions (indels) were identified in the 20 L. indica cultivars’ plastome and 25 SNPs were identified in the nrDNA. Phylogenetic analysis based on the plastome sequences showed that all the cultivars formed a clade with the species of L. indica, indicating that L. indica was the maternal donor of the cultivars. Population structure and PCA analyses supported two clades of cultivars, which exhibited significant genetic differences according to the plastome dataset. The results of the nrDNA supported that all 20 cultivars were divided into three clades and most of the cultivars had at least two genetic backgrounds and higher gene flow. Our results suggest that the plastome and nrDNA sequences can be used as molecular markers for assessing the genetic variation and relationships of L. indica cultivars. Full article

Objectives: In the “dual evaluation” of land space, the evaluation of the importance of ecosystem service functions and residential areas is important, playing a significant role in plants acting as carbon sinks and thereby achieving the transformation of low-carbon settlements. Methods: The paper compares and analyzes five models for quantifying carbon sink benefits and focuses on the national tree benefit calculator (NTBC) model, which is suitable for the carbon sequestration benefits of plants in residential areas, to (i) estimate and compare the economic benefits brought by trees and shrubs in residential areas, (ii) analyze the reasons for the differences between the current data and data for the next 20 years, and (iii) comprehensively evaluate the technical points related to the plant landscape in residential areas to assess whether they comply with the “Green Settlement Standard.” The index system was scored according to the standard. Result: The current data collected for existing trees and shrubs include the following: When the trees are in good condition, the order of the trees according to their economic benefits in the current year is Zelkova serrata > Cedrus deodara > Sapindus saponaria > Sophora japonica > Cinnamomum camphora > Prunus cerasifera > Magnolia grandiflora > Ulmus pumila > Acer L. > Lagerstroemia indica L. > Sapium sebiferum > Sabina > Punica granatum L. > Acer palmatum > Sapium sebiferum > Celtis sinensis Pers > Bambusa multiplex > Cycas > Melia azedarach L. > Pinus parviflora, and that of the trees in the next 20 years is Zelkova serrata > Cinnamomum camphora > Sophora japonica > Sapindus saponaria > Ulmus pumila > Cedrus deodara > Prunus cerasifera > Magnolia grandiflora > Acer L. > Sapium sebiferum > Cycas > Punica granatum L. > Lagerstroemia indica L. > Acer palmatum Thunb > Sabina > Bambusa multiplex > Broussonetia papyrifera > Celtis sinensis Pers > Melia azedarach L. > Pinus parviflora. The order of shrubs according to their economic gain in the current year is Photinia beauverdiana > Pittosporum tobira > Ligustrum lucidum > Viburnum odoratissimum > Buxus cephalantha, and that of the shrubs in the next 20 years is Ligustrum lucidum > Photinia beauverdiana > Pittosporum tobira > Buxus cephalantha > Viburnum odoratissimum. Conclusion: Using plants, the construction ideas, community structure and landscape maintenance of the carbon sink estimation system of residential areas should be updated according to three aspects to promote the quantification of the carbon sink benefits of green areas in urban settlements and the development of low-carbon settlements in China. Full article

Lagerstroemia indica is a widely used ornamental plant in summer gardens because of its desirable plant shape. The weeping traits of plants are related to secondary cell wall thickness and hormone signaling. NAC (NAM-ATAF1/2-CUC2), as one of the plant-specific transcription factors, is a switch for the secondary cell wall and also involved in leaf senescence, phytohormone signaling, and other growth processes. We identified a total of 21 LiNAC genes from the transcriptome data, which we divided into 14 subgroups and 2 groups. The physicochemical characteristics of amino acids, subcellular localization, transmembrane structure, GO and KEGG enrichment, and expression patterns were also examined. The qRT-PCR analysis showed that the expressions of LiNAC8 and LiNAC13 in upright L. indica ‘Shaoguifei’ and weeping L. indica ‘Xiariwuniang’ were significantly higher from the beginning to the end of growth stage (S1–S3), and the expressions of ‘Shaoguifei’ were always higher than those of ‘Xiariwuniang’. However, LiNAC2 showed a downward trend in S1–S3 and the relative expression level of ‘Shaoguifei’ was lower than that of ‘Xiariwuniang’. It is hypothesized that these LiNAC genes may be involved in the regulation of weeping traits in L. indica. The results of this study provide a basis for analyzing the functions of LiNAC genes and help to explore the molecular regulatory mechanisms related to the weeping traits in L. indica. Full article

One approach for solving the problem of antibiotic resistance and bacterial persistence in biofilms is treatment with metals, including silver in the form of silver nanoparticles (AgNPs). Green synthesis is an environmentally friendly method to synthesize nanoparticles with a broad spectrum of unique properties that depend on the plant extracts used. AgNPs with antibacterial and antibiofilm effects were obtained using green synthesis from plant extracts of Lagerstroemia indica (AgNPs_LI), Alstonia scholaris (AgNPs_AS), and Aglaonema multifolium (AgNPs_AM). Nanoparticles were characterized by transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) analysis. The ability to quench free radicals and total phenolic content in solution were also evaluated. The antibacterial activity of AgNPs was studied by growth curves as well as using a diffusion test on agar medium plates to determine minimal inhibitory concentrations (MICs). The effect of AgNPs on bacterial biofilms was evaluated by crystal violet (CV) staining. Average minimum inhibitory concentrations of AgNPs_LI, AgNPs_AS, AgNPs_AM were 15 ± 5, 20 + 5, 20 + 5 μg/mL and 20 ± 5, 15 + 5, 15 + 5 μg/mL against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, respectively. The E. coli strain formed biofilms in the presence of AgNPs, a less dense biofilm than the S. aureus strain. The highest inhibitory and destructive effect on biofilms was exhibited by AgNPs prepared using an extract from L. indica. Full article

Crapemyrtle bark scale (CMBS, Acanthococcus lagerstroemiae), an invasive polyphagous sap-sucking hemipteran, has spread across 14 states of the United States since 2004. The infestation of CMBS has negatively impacted the flowering of ornamental plants and even the fruiting of some crops. Host identification is critical for determining potential risks in ecosystems and industries and helps develop strategic management. A host confirmation test was performed over 25 weeks using six Lagerstroemia species (L. caudata, L. fauriei ‘Kiowa’, L. indica ‘Dynamite’, L. limii, L. speciosa, and L. subcostata) and California loosestrife (Lythrum californicum). The 25-week observations confirmed all tested plants as the hosts. The repeated measures of analysis of variance (ANOVA; Tukey’s HSD, $\alpha$ = 0.05) indicated that the average number of CMBS females differed significantly between L. limii and L. speciosa. The highest number of the females observed on L. limii was 576 ± 25 (mean ± SE) at 17 weeks after inoculation (WAI), while the highest number was 57 ± 15 on L. speciosa at 19 WAI. In addition, L. subcostata and L. speciosa had significantly high and low numbers of males, respectively, among the Lagerstroemia species. Our results suggest that L. speciosa could be incorporated in developing new cultivars with low CMBS suitability. Full article

Lagerstroemia indica is an important ornamental tree worldwide. The development of cultivars with colorful leaves and increased ornamental value represents one of the current main research topics. We investigated the anthocyanin profiles in two contrasting cultivars for leaf color phenotypes and explored the underlying molecular basis. Both cultivars display purple-red young leaves (Stage 1), and when the leaves mature (Stage 2), they turn green in HD (Lagerstroemia Dynamite) but remain unchanged in ZD (Lagerstroemia Ebony Embers). Seven different anthocyanins were detected, and globally, the leaves of ZD contained higher levels of anthocyanins than those of HD at the two stages with the most pronounced difference observed at Stage 2. Transcriptome sequencing revealed that in contrast to HD, ZD tends to keep a higher activity level of key genes involved in the flavonoid–anthocyanin biosynthesis pathways throughout the leaf developmental stages in order to maintain the synthesis, accumulation, and modification of anthocyanins. By applying gene co-expression analysis, we detected 19 key MYB regulators were co-expressed with the flavonoid–anthocyanin biosynthetic genes and were found strongly down-regulated in HD. This study lays the foundation for the artificial manipulation of the anthocyanin biosynthesis in order to create new L. indica cultivars with colorful leaves and increased ornamental value. Full article