Analysis of >3400 worldwide eggplant accessions reveals two independent domestication events and multiple migration-diversification routes.

Eggplant (Solanum melongena) is an important Solanaceous crop, widely cultivated and consumed in Asia, the Mediterranean basin, and Southeast Europe. Its domestication centers and migration and diversification routes are still a matter of debate. We report the largest georeferenced and genotyped collection to this date for eggplant and its wild relatives, consisting of 3499 accessions from seven worldwide genebanks, originating from 105 countries in five continents. The combination of genotypic and passport data points to the existence of at least two main centers of domestication, in Southeast Asia and the Indian subcontinent, with limited genetic exchange between them. The wild and weedy eggplant ancestor S. insanum shows admixture with domesticated S. melongena, similar to what was described for other fruit-bearing Solanaceous crops such as tomato and pepper and their wild ancestors. After domestication, migration and admixture of eggplant populations from different regions have been less conspicuous with respect to tomato and pepper, thus better preserving 'local' phenotypic characteristics. The data allowed the identification of misclassified and putatively duplicated accessions, facilitating genebank management. All the genetic, phenotypic, and passport data have been deposited in the Open Access G2P-SOL database, and constitute an invaluable resource for understanding the domestication, migration and diversification of this cosmopolitan vegetable.

Comparative physiology and transcriptome response patterns in cold-tolerant and cold-sensitive varieties of Solanum melongena.

BACKGROUND: Climate change has led to severe cold events, adversely impacting global crop production. Eggplant (Solanum melongena L.), a significant economic crop, is highly susceptible to cold damage, affecting both yield and quality. Unraveling the molecular mechanisms governing cold resistance, including the identification of key genes and comprehensive transcriptional regulatory pathways, is crucial for developing new varieties with enhanced tolerance. RESULTS: In this study, we conducted a comparative analysis of leaf physiological indices and transcriptome sequencing results. The orthogonal partial least squares discriminant analysis (OPLS-DA) highlighted peroxidase (POD) activity and soluble protein as crucial physiological indicators for both varieties. RNA-seq data analysis revealed that a total of 7024 and 6209 differentially expressed genes (DEGs) were identified from variety "A" and variety "B", respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment of DEGs demonstrated that the significant roles of starch and sucrose metabolism, glutathione metabolism, terpenoid synthesis, and energy metabolism (sucrose and starch metabolism) were the key pathways in eggplant. Weighted gene co-expression network analysis (WGCNA) shown that the enrichment of numerous cold-responsive genes, pathways, and soluble proteins in the MEgrep60 modules. Core hub genes identified in the co-expression network included POD, membrane transporter-related gene MDR1, abscisic acid-related genes, growth factor enrichment gene DELLA, core components of the biological clock PRR7, and five transcription factors. Among these, the core transcription factor MYB demonstrated co-expression with signal transduction, plant hormone, biosynthesis, and metabolism-related genes, suggesting a pivotal role in the cold response network. CONCLUSION: This study integrates physiological indicators and transcriptomics to unveil the molecular mechanisms responsible for the differences in cold tolerance between the eggplant cold-tolerant variety "A" and the cold-sensitive variety "B". These mechanisms include modulation of reactive oxygen species (ROS), elevation in osmotic carbohydrate and free proline content, and the expression of terpenoid synthesis genes. This comprehensive understanding contributes valuable insights into the molecular underpinnings of cold stress tolerance, ultimately aiding in the improvement of crop cold tolerance.

Genome-wide characterization of SmZHD gene family and the role of SmZHD12 in regulating anthocyanin biosynthesis in eggplant (Solanum melongena L.).

KEY MESSAGE: SmZHDs was highly expressed in anthocyanin-rich parts of eggplant. SmZHD12 can activate the expression of SmCHS, SmANS, SmDFR and SmF3H. Overexpression of SmZHD12 promotes anthocyanin biosynthesis in Arabidopsis. The Zinc finger-homeodomain (ZHD) proteins family genes are known to play a significant role in plant development and physiological processes. However, the evolutionary history and function of the ZHD gene family in eggplant remain largely unexplored. This study categorizes a total of 15 SmZHD genes into SmMIF and SmZHD subfamilies based on conserved domains. The phylogeny, gene structure, conserved motifs, promoter elements, and chromosomal locations of the SmZHD genes were comprehensively analyzed. Tissue expression profiles indicate that the majority of SmZHD genes are expressed in anthocyanin-rich areas. qRT-PCR assays revealed distinct expression patterns of SmZHD genes in response to various treatments, indicating their potential involvement in multiple signaling pathways. Analysis of transcriptomic data from light-treated eggplant peel identified SmZHD12 as the most light-responsive gene among the 15 SmZHD genes. Consequently, this study provides further evidence that SmZHD12 facilitates anthocyanin accumulation in Arabidopsis leaves by upregulating the expression of anthocyanin biosynthesis structural genes, as confirmed by dual-luciferase assays and Arabidopsis genetic transformation. Our study will lay a solid foundation for the in-depth study of the involvement of SmZHD genes in the regulation of anthocyanin biosynthesis.

Genetic and Biotechnological Approaches to Improve Fruit Bioactive Content: A Focus on Eggplant and Tomato Anthocyanins.

Anthocyanins are a large group of water-soluble flavonoid pigments. These specialized metabolites are ubiquitous in the plant kingdom and play an essential role not only in plant reproduction and dispersal but also in responses to biotic and abiotic stresses. Anthocyanins are recognized as important health-promoting and chronic-disease-preventing components in the human diet. Therefore, interest in developing food crops with improved levels and compositions of these important nutraceuticals is growing. This review focuses on work conducted to elucidate the genetic control of the anthocyanin pathway and modulate anthocyanin content in eggplant (Solanum melongena L.) and tomato (Solanum lycopersicum L.), two solanaceous fruit vegetables of worldwide relevance. While anthocyanin levels in eggplant fruit have always been an important quality trait, anthocyanin-based, purple-fruited tomato cultivars are currently a novelty. As detailed in this review, this difference in the anthocyanin content of the cultivated germplasm has largely influenced genetic studies as well as breeding and transgenic approaches to improve the anthocyanin content/profile of these two important solanaceous crops. The information provided should be of help to researchers and breeders in devising strategies to address the increasing consumer demand for nutraceutical foods.

Discovery of a DFR gene that controls anthocyanin accumulation in the spiny Solanum group: roles of a natural promoter variant and alternative splicing.

Anthocyanins are important pigments that impart color in plants. In Solanum, different species display various fruit or flower colors due to varying degrees of anthocyanin accumulation. Here we identified two anthocyanin-free mutants from an ethylmethane sulfonate-induced mutant library and naturally occurring mutants in Solanum melongena, with mutations in the 5' splicing site of the second intron of dihydroflavonol-4-reductase (DFR) - leading to altered splicing. Further study revealed that alternative splicing of the second intron was closely related to anthocyanin accumulation in 17 accessions from three cultivated species: S. melongena, Solanum macrocarpon and Solanum aethiopicum, and their wild related species. Analysis of natural variations of DFR, using an expanded population including 282 accessions belonging to the spiny Solanum group, identified a single-nucleotide polymorphism in the MYB recognition site in the promoter region, which causes differential expression of DFR and affects anthocyanin accumulation in fruits of the detected accessions. Our study suggests that, owing to years of domestication, the natural variation in the DFR promoter region and the alternative splicing of the DFR gene account for altered anthocyanin accumulation during spiny Solanum domestication.

Characteristics, Comparative Analysis, and Phylogenetic Relationships of Chloroplast Genomes of Cultivars and Wild Relatives of Eggplant (Solanum melongena).

The eggplant (Solanum melongena) is a popular vegetable around the world. However, the origin and evolution of eggplant has long been considered complex and unclear, which has become the barrier to improvements in eggplant breeding. Sequencing and comparative analyses of 13 complete chloroplast (cp) genomes of seven Solanum species were performed. Genome sizes were between 154,942 and 156,004 bp, the smallest genome was from S. torvum and the largest from S. macrocapon. Thirteen cp genomes showed highly conserved sequences and GC contents, particularly at the subgenus level. All genes in the 13 genomes were annotated. The cp genomes in this study comprised 130 genes (i.e., 80 protein-coding genes, 8 rRNA genes, and 42 tRNA genes), apart from S. sisymbriifolium, which had 129 (79 protein-coding genes, 8 rRNA genes, and 42 tRNA genes.). The rps16 was absent from the cp genome of S. sisymbriifolium, resulting in a nonsense mutation. Twelve hotspot regions of the cp genome were identified, which showed a series of sequence variations and differed significantly in the inverted repeat/single-copy boundary regions. Furthermore, phylogenetic analysis was conducted using 46 cp genomic sequences to determine interspecific genetic and phylogenetic relationships in Solanum species. All species formed two branches, one of which contained all cultivars of the subgenus Leptostemonum. The cp genome data and phylogenetic analysis provides molecular evidence revealing the origin and evolutionary relationships of S. melongena and its wild relatives. Our findings suggest precise intra- and interspecies relatedness within the subgenus Leptostemonum, which has positive implications for work on improvements in eggplant breeding, particularly in producing heterosis, expanding the source of species variation, and breeding new varieties.

Transcriptomics reveals the molecular mechanisms of flesh colour differences in eggplant (Solanum melongena).

BACKGROUND: Fruit flesh colour is not only an important commodity attribute of eggplant but is also closely related to maturity. However, very little is known about its formation mechanism in eggplant. RESULTS: Two inbred lines of eggplant, green 'NC7' and white 'BL', were used in this study to explain the differences in flesh colour. Transcriptome sequencing results revealed a total of 3304 differentially expressed genes (DEGs) in NC7 vs. BL. Of the DEGs obtained, 2050 were higher and 1254 were lower in BL. These DEGs were annotated to 126 pathways, where porphyrin and chlorophyll metabolism, flavonoid biosynthesis, and photosynthesis-antenna proteins play vital roles in the colour formation of eggplant flesh. At the same time, Gene Ontology (GO) enrichment significance analysis showed that a large number of unigenes involved in the formation of chloroplast structure were lower in BL, which indicated that the formation of chloroplasts in white-fleshed eggplant was blocked. This was confirmed by transmission electron microscopy (TEM), which found only leucoplasts but no chloroplasts in the flesh cells of white-fleshed eggplant. Several genes encoding ERF and bHLH transcription factors were predicted to participate in the regulation of chlorophyll biosynthetic genes. CONCLUSIONS: The results of this study indicated that differences in the gene expression of the chlorophyll metabolic pathway were the main cause of the different flesh colour formations. These findings will increase our understanding of the genetic basis in eggplant flesh colors formation mechanism.

Chemical ecology of Himalayan eggplant variety's antixenosis: identification of geraniol as an oviposition deterrent against the eggplant shoot and fruit borer.

Eggplant (Solanum melongena) suffers severe losses due to a multi-insecticide-resistant lepidopteran pest, shoot and fruit borer (SFB, Leucinodes orbonalis). Heavy and combinatorial application of pesticides for SFB control renders eggplant risky for human consumption. We observed that gravid SFB females do not oviposit on Himalayan eggplant variety RC-RL-22 (RL22). We hypothesized that RL22 contained an antixenosis factor. Females' behavior indicated that the RL22 cue they perceived was olfactory. To identify it, leaf volatile blends of seven eggplant varieties were profiled using solid phase microextraction and gas chromatography mass spectrometry. Seven RL22-specific compounds were detected in the plant headspace. In choice assays, oviposition deterrence efficacies of these candidate compounds were independently tested by their foliar application on SFB-susceptible varieties. Complementation of geraniol, which was exclusively found in RL22, reduced oviposition (> 90%). To validate geraniol's role in RL22's SFB-deterrence, we characterized RL22's geraniol synthase and silenced its gene in planta, using virus-induced gene silencing. Geraniol biosynthesis suppression rendered RL22 SFB-susceptible; foliar geraniol application on the geraniol synthase-silenced plants restored oviposition deterrence. We infer that geraniol is RL22's SFB oviposition deterrent. The use of natural compounds like geraniol, which influence the chemical ecology of oviposition, can reduce the load of hazardous synthetic larvicides.

Conventional and new genetic resources for an eggplant breeding revolution.

Eggplant (Solanum melongena) is a major vegetable crop with great potential for genetic improvement owing to its large and mostly untapped genetic diversity. It is closely related to over 500 species of Solanum subgenus Leptostemonum that belong to its primary, secondary, and tertiary genepools and exhibit a wide range of characteristics useful for eggplant breeding, including traits adaptive to climate change. Germplasm banks worldwide hold more than 19 000 accessions of eggplant and related species, most of which have yet to be evaluated. Nonetheless, eggplant breeding using the cultivated S. melongena genepool has yielded significantly improved varieties. To overcome current breeding challenges and for adaptation to climate change, a qualitative leap forward in eggplant breeding is necessary. The initial findings from introgression breeding in eggplant indicate that unleashing the diversity present in its relatives can greatly contribute to eggplant breeding. The recent creation of new genetic resources such as mutant libraries, core collections, recombinant inbred lines, and sets of introgression lines will be another crucial element and will require the support of new genomics tools and biotechnological developments. The systematic utilization of eggplant genetic resources supported by international initiatives will be critical for a much-needed eggplant breeding revolution to address the challenges posed by climate change.

Pseudomonas solani sp. nov. isolated from the rhizosphere of eggplant in Japan.

The search for bacteria that can be used as biocontrol agents to control crop diseases yielded a promising candidate, Sm006T, which was isolated from the rhizosphere of eggplant (Solanum melongena) growing in a field in Aichi Prefecture, Japan, in 2006. The cells were Gram-stain-negative, aerobic, non-spore-forming, rod-shaped and motile with one polar flagellum. The results of homology searches and phylogenetic analyses based on the 16S rRNA gene sequence indicated that Sm006T represents a member of the genus Pseudomonas. The genomic DNA G+C content was 66.3 mol% and the major cellular fatty acids (more than 5 % of the total fatty acids) were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C12 : 0. Phylogenetic analyses using the rpoD gene sequence and phylogenomic analysis of the whole genome sequence revealed that Sm006T represents a member of the Pseudomonas resinovorans group; however, its phylogenetic position does not match that of any known species of the genus Pseudomonas. The average nucleotide identity and digital DNA-DNA hybridisation values between the strain and closely related species were lower than the thresholds for prokaryotic species delineation (95-96 and 70 %, respectively), with the highest values observed for Pseudomonas tohonis TUM18999T (92.05 and 46.3 %, respectively). Phenotypic characteristics, cellular fatty acid composition and possession of 2,4-diacetylphloroglucinol biosynthetic gene cluster could be used to differentiate the strain from its closest relatives. The phenotypic, chemotaxonomic and genotypic data obtained during this study indicated that Sm006T represents a novel species of the genus Pseudomonas, for which we propose the name Pseudomonas solani sp. nov., with Sm006T (= MAFF 212523T = ICMP 24689T) as the type strain.

Comparative transcriptomic analysis of early fruit development in eggplant (Solanum melongena L.) and functional characterization of SmOVATE5.

KEY MESSAGE: Comparative transcriptome analysis of early fruits of long and round eggplants, SmOVATE5, is involved in regulating fruit development. Eggplant, a solanaceous crop that has undergone a long period of domestication, is one of the most important vegetables worldwide. The shape of its fruit is an important agronomic trait and consumers in different regions have different preferences. However, a limited understanding of the molecular mechanisms regulating fruit development and shape has hindered eggplant breeding. In this study, we performed morphological observations and transcriptome analysis of long- and round-fruited eggplant genotypes to understand the molecular regulation during the early development of different fruit shapes. Morphological studies revealed that the two varieties already exhibited distinctly different phenotypes at the initial stage of fruit development before flowering, with rapid fruit enlargement beginning on the sixth day after flowering. Comparative transcriptome analysis identified phytohormone-related genes that were significantly upregulated on the day of flowering, indicating they may be involved in regulating the initial stages of fruit development. Notably, SmARF1 showed a sustained upregulation pattern in both varieties, suggesting that it may promote eggplant fruit growth. In addition, several differentially expressed genes of the SUN, YABBY, and OVATE families are potentially involved in the regulation of fruit development or fruit shape. We demonstrated that the SmOVATE5 gene has a negative regulatory function suppressing plant growth and development. In conclusion, this study provides new insights into the molecular regulatory mechanisms of eggplant fruit development, and the genes identified may provide valuable references for different fruit shape breeding programs.

Brinjal (Solanum melongena) stalk waste as an effective scavenger for Eriochrome Black-T from water and wastewater: an approach towards waste to best.

Stalks of brinjal (Solanum melongena), hereinafter SM, have been exercised as an efficient and sustainable adsorbent material for the elimination of Eriochrome Black-T (EBT) from an aqueous solution. The material was characterized by FTIR, FESEM, BET surface area, pHpzc, and proximate analysis. FTIR spectrum suggests the presence of polyphenolic moieties, responsible for successful dye binding. FESEM images show an unprecedented octopus-like texture containing micropores. The central head transforms the architecture of a flower. The evaluated BET surface area of 10.042 m2/g and pore volume 1.055 × 10-2 cm3/g suggest a porous material. The pHpzc of the material was evaluated to be 7.05, and under optimized conditions, the maximum adsorption capacity was found 52.631 mg/g at pH 7. The operational parameters were studied concerning contact time (0-90 min), pH (5-11), initial concentration (10-40 mg/L), and interfering ions (PO4-3, AsO4-3, Hg+2, Pb+2). Adsorption follows Langmuir isotherm best (R2 = 0.996), and pseudo-second-order kinetics (R2 = 0.991) indicate a monolayer and homogeneous adsorption. 83% regeneration was successful with 0.1(M) sodium hydroxide solution. The material can be reused for up to three cycles with 90% efficiency retention. Analysis of EBT containing industrial effluent indicates that 52.62% of EBT can be removed.

Brinjal (Solanum melongena), being one of the most cultivated vegetables around the globe, generates voluminous waste as stalks which warrant proper management. With this aim, such stalks were converted to a phytosorbent and selected for removal of Eriochrome black-T (EBT), a dye that is used by industry persons and science students in their laboratory experiments. The prepared material is highly porous, water-stable, regenerable, and reusable. The protocol is economically viable, easy, and efficient for industrial effluent treatment as well. With a notable maximum adsorption capacity of 52.631 mg/g, the material could offer an ideal choice for dye decontamination.

Genome-Wide Identification of Catalase Gene Family and the Function of SmCAT4 in Eggplant Response to Salt Stress.

Salinity is an important abiotic stress, damaging plant tissues by causing a burst of reactive oxygen species (ROS). Catalase (CAT) enzyme coded by Catalase (CAT) genes are potent in reducing harmful ROS and hydrogen peroxide (H2O2) produced. Herein, we performed bioinformatics and functional characterization of four SmCAT genes, retrieved from the eggplant genome database. Evolutionary analysis CAT genes revealed that they are divided into subgroups I and II. The RT-qPCR analysis of SmCAT displayed a differential expression pattern in response to abiotic stresses. All the CAT proteins of eggplant were localized in the peroxisome, except for SmCAT4, which localized in the cytomembrane and nucleus. Silencing of SmCAT4 compromised the tolerance of eggplant to salt stress. Suppressed expression levels of salt stress defense related genes SmTAS14 and SmDHN1, as well as increase of H2O2 content and decrease of CAT enzyme activity was observed in the SmCAT4 silenced eggplants. Our data provided insightful knowledge of CAT gene family in eggplant. Positive regulation of eggplant response to salinity by SmCAT4 provides resource for future breeding programs.

Improved genome assembly and pan-genome provide key insights into eggplant domestication and breeding.

Eggplant (Solanum melongena L.) is an important horticultural crop and one of the most widely grown vegetables from the Solanaceae family. It was domesticated from a wild, prickly progenitor carrying small, round, non-anthocyanic fruits. We obtained a novel, highly contiguous genome assembly of the eggplant '67/3' reference line, by Hi-C retrofitting of a previously released short read- and optical mapping-based assembly. The sizes of the 12 chromosomes and the fraction of anchored genes in the improved assembly were comparable to those of a chromosome-level assembly. We resequenced 23 accessions of S. melongena representative of the worldwide phenotypic, geographic, and genetic diversity of the species, and one each from the closely related species Solanum insanum and Solanum incanum. The eggplant pan-genome contained approximately 51.5 additional megabases and 816 additional genes compared with the reference genome, while the pan-plastome showed little genetic variation. We identified 53 selective sweeps related to fruit color, prickliness, and fruit shape in the nuclear genome, highlighting selection leading to the emergence of present-day S. melongena cultivars from its wild ancestors. Candidate genes underlying the selective sweeps included a MYBL1 repressor and CHALCONE ISOMERASE (for fruit color), homologs of Arabidopsis GLABRA1 and GLABROUS INFLORESCENCE STEMS2 (for prickliness), and orthologs of tomato FW2.2, OVATE, LOCULE NUMBER/WUSCHEL, SUPPRESSOR OF OVATE, and CELL SIZE REGULATOR (for fruit size/shape), further suggesting that selection for the latter trait relied on a common set of orthologous genes in tomato and eggplant.

Genetic mapping of simply inherited categorical traits, including anthocyanin accumulation profiles and fruit appearance, in eggplant (Solanum melongena).

BACKGROUND: The appearance quality of the eggplant (Solanum melongena L.) fruit is an important trait that influences its commercial value. It is known that quality traits such as anthocyanin composition and fruit surface pattern are categorical and are inherited simply. However, research examples of gene mapping for the composition (anthocyanin accumulation profile) and the surface pattern in eggplant fruit are limited. METHODS AND RESULTS: To map loci for these traits including the accumulation profiles of two anthocyanins, a widely spreading anthocyanin, delphinidin 3-(p-coumaroyl) rutinoside-5-glucoside (nasunin), and the relatively rare delphinidin 3-glucoside (D3G), we used two F2 intracrossed populations (LWF2 and N28F2). For the LWF2 population, mapping was achieved by reconstructing the linkage map created by Fukuoka et al. [1]. In the case of the N28F2 population, we constructed a linkage map consisting of 13 linkage groups using 238 simple sequence repeats, 75 single-nucleotide polymorphisms. Using the two F2 populations, the nasunin accumulating profile, the striped pattern on the fruit surface, the colors of flowers, fruit, and calyxes, and the D3G accumulating profile were genetically mapped. Furthermore, by utilizing the eggplant reference genome information, mutations in the causative candidate genes for those loci were identified. CONCLUSION: Overall, the results of this study suggest that inactivation of key enzymes of anthocyanin metabolism and the gene orthologous to the tomato u gene are potential causes of observed variety in eggplant appearance traits.

Potential of biosynthesized zinc oxide nanoparticles to control Fusarium wilt disease in eggplant (Solanum melongena) and promote plant growth.

In this study, a novel, non-toxic, eco-friendly zinc oxide nanoparticles (ZnO-NPs) was used instead of the synthetic fungicides widely used to control the destructive phytopathogenic fungus Fusarium oxysporum, the causative agent of wilt disease in Solanum melongena L. Herein, the biosynthesized ZnO-NPs was carried out by Penicillium expansum ATCC 7861. In vitro, mycosynthesized ZnO-NPs exhibited antifungal activity against Fusarium oxysporum. In vivo, ZnO-NPs suppressed Fusarium wilt disease in cultivated Solanum melongena L. by decreasing the disease severity with 75% of plant protection. Moreover, ZnO-NPs stimulated the recovery of eggplant as an indicated by improving of morphological and metabolic indicators including plant height(152.5%), root length(106.6%), plant fresh biomass (146%), chlorophyll a (102.8%), chlorophyll b (67.86%), total soluble carbohydrates (48.5%), total soluble protein (81.8%), phenol (10.5%), antioxidant activity and isozymes compared with infected control. Therefore, this study suggests using mycosynthesized ZnO-NPs as an alternative to synthetic fungicides not only to eradicate the Fusarium wilt disease in cultivated eggplant (Solanum melongena) but also to promote the growth parameters and metabolic aspects.

Comparative genomic investigation of TCP gene family in eggplant (Solanum melongena L.) and expression analysis under divergent treatments.

KEY MESSAGE: The putative TCP genes and their responses to abiotic stress in eggplant were comprehensively characterized, and SmTCP genes (Smechr0202855.1 and Smechr0602431.1) may be involved in anthocyanin synthesis. The Teosinte branched1/Cycloidea/Proliferating cell factors (TCPs), a family of plant-specific transcription factors, plays paramount roles in a plethora of developmental and physiological processes. We here systematically characterized putative TCP genes and their response to abiotic stress in eggplant. In total, 30 SmTCP genes were categorized into two subfamilies based on the classical TCP conserved domains. Chromosomal location analysis illustrated the random distribution of putative SmTCP genes along 12 eggplant chromosomes. Cis-acting elements and miRNA target prediction suggested that versatile and complicated regulatory mechanisms that control SmTCPs gene expression, and 3 miRNAs (miR319a, miR319b, and miR319c-3p) might act as major regulators targeting SmTCPs. Tissue expression profiles indicated divergent spatiotemporal expression patterns of SmTCPs. qRT-PCR assays demonstrated different expression profiles of SmTCP under 4 °C, drought and ABA treatment conditions, suggesting the possible participation of SmTCP genes in multiple signaling pathways. Furthermore, RNA-seq data of eggplant anthocyanin synthesis coupled with yeast one-hybrid and dual-luciferase assays suggested the involvement of SmTCP genes (Smechr0202855.1 and Smechr0602431.1) in the mediation of anthocyanin synthesis. Our study will facilitate further investigation on the putative functional characterization of eggplant TCP genes and lay a solid foundation for the in-depth study of the involvement of SmTCP genes in the regulation of anthocyanin synthesis.

Comparative proteomic analysis reveals insights into the response of Cryptolaemus montrouzieri to bottom-up transfer of cadmium and lead across a multi-trophic food chain.

Contamination of agro-ecosystems with heavy metals can affect the development and reproduction of insect natural enemies. This study reports a detailed Tandem Mass Tag based quantitative proteomic analysis of underlying mechanisms responsible for stress response of Cryptolaemus montrouzieri against heavy metals (cadmium (Cd) and lead (Pb)) transported across a multi-trophic food chain. A total of 6639 proteins were detected under Cd as well as Pb stress. In Pb versus the control cluster, 69 proteins (28 up-regulated and 41 down-regulated) were differentially expressed whereas 268 proteins were differentially expressed under Cd versus the control cluster, having 198 proteins up-regulated and 70 down-regulated proteins. The analysis of differentially expressed proteins showed that 27 proteins overlapped in both clusters representing the core proteome to Pb and Cd stress. The bioinformatics analysis demonstrated that these proteins were mapped to 57 and 99 pathways in Pb versus control and Cd versus control clusters, respectively. The functional classification by COG, GO and KEGG databases showed significant changes in protein expression by C. montrouzieri under Pb and Cd stress. The heavy metal stress (Pb and Cd) induced significant changes in expression of proteins like hexokinase (HK), succinyl-CoA, trypsin like proteins, cysteine proteases, cell division cycle proteins, and yellow gene proteins. The results provide detailed information on the protein expression levels of C. montrouzieri and will serve as basic information for future proteomic studies on heavy metal responses of insect predators within a multi-trophic food chain.

First report of Anthracnose on 'Purple Dream' Solanum melongena in Malaysia Caused by Colletotrichum siamense.

'Purple Dream' eggplant (Solanum melongena) is widely grown for its edible fruits in Malaysia. In July 2021, anthracnose symptoms were observed on fruit with a disease severity of approximately 80% and an incidence of 10% in a field (14.6 m2) (5°56'50.9"N, 116°04'31.9"E) located in the Penampang district of Sabah province. The symptoms initially appeared as irregular light brown spots. As the disease progressed, the spots enlarged and merged into extensive lesion patches that appeared in concentric circles. The symptomatic fruit tissues (5 x 5 mm) were surface sterilized based on Khoo et al. (2022), and plated onto potato dextrose agar (PDA), and incubated at 25°C in the dark. Colonies with gray-white fluffy mycelia developed after 7 days, and the reverse of the colonies was dark brown. A representative isolate named Penampang was characterized morphologically and molecularly. The conidia were one-celled, cylindrical, blunt at the ends, hyaline, smooth, and measured 13.3 to 16.1 x 3.9 to 6.0 µm (n= 20). Appressoria ranged in size from 7.6 to 9.3 m x 5.5 to 6.6 µm (n= 20) and were spherical to irregular in shape and dark brown in colour. Genomic DNA was extracted from fresh mycelia of isolate Penampang based on Khoo et al. (2021) and Khoo et al. (2022). ITS1/ITS4, CL1C/CL2C, ACT-512F/ACT-783R, CHS-79F/CHS-354R, and GDF1/GDR1 primer pairs were used to amplify the isolate's internal transcribed spacer region (ITS), and partial calmodulin (CAL), actin (ACT), chitin synthase (CHS-1), and glyceraldehyde-3-phosphate dehydrogenase genes (GAPDH) (Weir et al. 2012). PCR products were sequenced by Apical Scientific Sdn. Bhd. (Selangor, Malaysia). Sequences were deposited in GenBank under the accession numbers OL957466 (ITS), OL953035 (CAL), OL953032 (ACT), OL953038 (CHS-1), and OL953041 (GAPDH). They were 99% to 100% identical to the Colletotrichum ti ITS (NR_120143) (515 bp out of 519 bp), and C. siamense CAL (JX009714) (729 bp out of 731 bp), ACT (JX009518) (282 bp out of 282 bp), CHS-1 (JX009865) (299 bp out of 299 bp), and GAPDH (JX009924) (276 bp out of 277 bp) sequences. ITS sequences do not reliably resolve relationships within the C. gloeosporioides complex (Weir et al. 2012). The phylogenetic maximum likelihood analysis using the combined ITS, CAL, ACT, CHS-1, and GAPDH sequences indicated that the isolate was part of the C. siamense clade (100% bootstrap value) that also contained the type isolate ICMP 18578 of this species. Morphological and molecular characterization matched the description of C. siamense (Huang et al. 2021; Ismail et al. 2021). Koch's postulates were performed similarly as described by Chai et al. (2017) but using spray-inoculation (108 spores/ml) of three healthy 'Purple Dream' eggplant fruit with isolate Penampang. Water was sprayed on three additional fruits that served as controls. All the fruits were incubated at 25°C and less than 90% relative humidity. Symptoms similar to those observed in the field developed 5 days after inoculation. No symptoms occurred on controls. The experiment was repeated two more times. The reisolated fungi were identical to the pathogen morphologically and molecularly. To our knowledge, this is the first report of C. siamense causing anthracnose on fruit of 'Purple Dream' S. melongena in Malaysia as well as worldwide. Our findings expand the host range of C. siamense and indicate that the pathogen could potentially limit 'Purple Dream' eggplant production in Malaysia.

Comparative transcriptome analysis provides insight into the molecular mechanisms of anther dehiscence in eggplant (Solanum melongena L.).

Anther dehiscence releases pollen and therefore is a key event in plant sexual reproduction. Although anther dehiscence has been intensively studied in some plants, such as Arabidopsis thaliana and rice (Oryza sativa), the molecular mechanism of anther dehiscence in eggplant (Solanum melongena) is largely unknown. To provide insight into this mechanism, we used RNA-sequencing (RNA-seq) to analyze the transcriptomic profiles of one natural male-fertile line (F142) and two male-sterile lines (S12 and S13). We assembled 88,414 unigenes and identified 3446 differentially expressed genes (DEGs). GO and KEGG analysis indicated that these DEGs were mainly involved in "metabolic process", "catalytic activity", "biosynthesis of amino acids", and "carbon metabolism". The present study provides comprehensive transcriptomic profiles of eggplants that do and do not undergo anther dehiscence, and identifies a number of genes and pathways associated with anther dehiscence. The information deepens our understanding of the molecular mechanisms of anther dehiscence in eggplant.