Light is a key environmental factor affecting anthocyanin biosynthesis. Our previous study demonstrated that “Lanshan Hexian” is a light‐sensitive eggplant cultivar, but its regulatory mechanism is ...unknown. Here, delphinidin‐3‐4‐(cis‐p‐coumaroyl)‐rhamnosyl‐glucopyranoside‐5‐glucopyranoside and delphinidin‐3‐4‐(trans‐p‐coumaroyl)‐rhamnosyl‐glucopyranoside‐5‐glucopyranoside were identified as the main anthocyanin components in Lanshan Hexian by ultra‐performance liquid chromatography‐tandem mass spectrometry. Three time points of anthocyanin accumulation, including the start point (0 day), fastest point (5 days), and highest point (12 day), were investigated by using ribonucleic acid sequencing and iTRAQ technology. The corresponding correlation coefficients of differentially expressed genes, and differentially expressed proteins were 0.6936, 0.2332, and 0.6672. Anthocyanin biosynthesis was a significantly enriched pathway, and CHI, F3H, 3GT, 5GT, and HY5 were regulated at both transcriptional and translational levels. Moreover, some transcription factors and photoreceptors may participate in light‐induced anthocyanin biosynthesis like the known transcription factors MYB113 and TT8. The transient expression assay indicated that SmMYB35, SmMYB44, and a SmMYB86 isoform might involve in the light‐induced anthocyanin biosynthesis pathway. Finally, a regulatory model for light‐induced anthocyanin biosynthesis in eggplant was constructed. Our work provides a new direction for the study of the molecular mechanisms of light‐induced anthocyanin biosynthesis in eggplant.
Eggplant (Solanum melongena L.) with purple peel is rich in anthocyanins, but the concentration is affected seriously by light in actual production. In this study, delphinidin‐3‐4‐(cis‐p‐coumaroyl)‐rhamnosyl‐glucopyranoside‐5‐glucopyranoside and delphinidin‐3‐4‐(trans‐p‐coumaroyl)‐rhamnosyl‐glucopyranoside‐5‐glucopyranoside were identified as the main intermediate products in Lanshan Hexian, and the underlying molecular mechanism of light‐induced anthocyanin biosynthesis in eggplant were analyzed using ribonucleic acid sequencing and iTRAQ technology. Strikingly, the transient expression assay indicated that SmMYB35, SmMYB44, and a SmMYB86 isoform might involve in light‐induced anthocyanin biosynthesis by directly or indirectly regulating the structural genes expression. These comprehensive dataset will be conducive to reducing the poor colour production under weak light conditions in the future.
The consistently increasing use of zinc oxide nanoparticles (ZnONPs) in crop optimization practices and their persistence in agro-environment necessitate expounding their influence on sustainable ...agro-environment. Attempts have been made to understand nanoparticle-plant beneficial bacteria (PBB)- plant interactions; the knowledge of toxic impact of nanomaterials on soil-PBB-vegetable systems and alleviating nanotoxicity using PBB is scarce and inconsistent. This study aims at bio-fabrication of ZnONPs from Rosa indica petal extracts and investigates the impact of PBB on growth and biochemical responses of biofertilized eggplants exposed to phyto-synthesized nano-ZnO. Microscopic and spectroscopic techniques revealed nanostructure, triangular shape, size 32.5 nm, and different functional groups of ZnONPs and petal extracts. Inoculation of Pseudomonas fluorescens and Azotobacter chroococcum improved germination efficiency by 22% and 18% and vegetative growth of eggplants by 14% and 15% under NPs stress. Bio-inoculation enhanced total chlorophyll content by 36% and 14 %, increasing further with higher ZnONP concentrations. Superoxide dismutase and catalase activity in nano-ZnO and P. fluorescens inoculated eggplant shoots reduced by 15–23% and 9–11%. Moreover, in situ experiment unveiled distortion and accumulation of NPs in roots revealed by scanning electron microscope and confocal laser microscope. The present study highlights the phytotoxicity of biosynthesized ZnONPs to eggplants and demonstrates that PBB improved agronomic traits of eggplants while declining phytochemicals and antioxidant levels. These findings suggest that P. fluorescens and A. chroococcum, with NPs ameliorative activity, can be cost-effective and environment-friendly strategy for alleviating NPs toxicity and promoting eggplant production under abiotic stress, fulfilling vegetable demands.
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•Zinc oxide nanoparticles phyto-fabricated from R. indica petals decline growth and alter biochemical responses of eggplants.•Scanning electron microscopy and confocal laser microscopy revealed cellular damage in NPs-treated eggplants.•Plant-beneficial bacteria, P. fluorescens and A. chroococcum, enhance eggplant defense against NPs toxicity.•Plant-beneficial bacteria caused metabolic shifts in proline, malonaldehyde, and antioxidants and alleviated abiotic stress.•NPs alleviation potential of P. fluorescens and A. chroococcum can magnify eggplants production even under abiotic stress.
Eggplant (Solanum melongena L.) is an edible fruit vegetable cultivated and consumed worldwide. The purple eggplant is more eye-catching and popular for the health-promoting anthocyanins contained in ...the fruit skin. Two kinds of anthocyanin were separated and identified from purple cultivar (Zi Chang) by high-performance liquid chromatography–electrospray ionization tandem mass spectrometry. To investigate the molecular mechanisms of anthocyanin accumulation in eggplant, the transcripts of anthocyanin biosynthetic and regulatory genes were analyzed in the fruit skin and the flesh of the purple cultivar and the white cultivar (Bai Xue). Compared with the other tissues, SmMYB1 and all anthocyanin biosynthetic genes except PAL were dramatically upregulated in the fruit skin of the purple cultivar. Overexpression of SmMYB1 activated abundant anthocyanin accumulation in the regenerating shoots of eggplant. These results prove that transcriptional activation of SmMYB1 accounts for constitutive upregulation of most anthocyanin biosynthetic genes and the onset of anthocyanin biosynthesis in the purple cultivar.
The continuous deterioration of arable lands by metal pollution compels finding suitable strategies to increase plant tolerance under contaminated regimes. Current study was designed to examine the ...synergistic role of Bacillus subtilis FBL-10 and silicon (Si) with respect to mitigation of lead (Pb) induced phytotoxicity in Solanum melongena L. Lead stress (75 mg kg−1) reduced chlorophyll (Chl) content, photosynthetic rate and gas exchange characteristics of S. melongena plants. The Si and B. subtilis FBL-10 individually upgraded all the above-mentioned growth attributes. However, co-application of Si (50 mg kg−1) and B. subtilis FBL-10 significantly improved biochemical and growth attributes of Pb challenged plants. The abridged levels of oxidative markers including hydrogen peroxide (H2O2), and malondialdehyde (MDA) besides reduced Pb accumulation in foliage tissues, were recorded in Si and microbe assisted plants. Furthermore, plants inoculated with B. subtilis FBL-10 alone or in combination with Si showed increment in total soluble proteins, photosynthetic rate and gas exchange attributes. The inoculated plants treated with Si exhibited higher level of auxins and improved activity of antioxidant enzymes under Pb stress. Present research elucidates interactive role of B. subtilis FBL-10 and Si in reduction of Pb toxicity in S. melongena plants. Alone application of Si or B. subtilis FBL-10 was less effective for attenuation of Pb stress; however, synergism between both phyto-protectants demonstrated fabulous ability for Pb stress assuagement. Consequently, executions of field studies become indispensable to comprehend the efficacy of Si applied alone or in combination with plant growth promoting bacteria (PGPB) like B. subtilis FBL-10. From current research, it is concluded that the interaction of Si and PGPB seems an auspicious technique and eco-friendly approach to enhance metal tolerance in crop plants.
•B. subtilis FBL-10 and Si alleviate Pb stress in S. Melongena.•B. subtilis FBL-10 and Si improve plant growth and activate antioxidant system of plants.•B. subtilis FBL-10 and Si decrease levels of H2O2 and MDA besides Pb accumulation in plants.
With approximately 450 species, spiny Solanum species constitute the largest monophyletic group in the Solanaceae family, but a high-quality genome assembly from this group is presently missing. We ...obtained a chromosome-anchored genome assembly of eggplant (Solanum melongena), containing 34,916 genes, confirming that the diploid gene number in the Solanaceae is around 35,000. Comparative genomic studies with tomato (S. lycopersicum), potato (S. tuberosum) and pepper (Capsicum annuum) highlighted the rapid evolution of miRNA:mRNA regulatory pairs and R-type defense genes in the Solanaceae, and provided a genomic basis for the lack of steroidal glycoalkaloid compounds in the Capsicum genus. Using parsimony methods, we reconstructed the putative chromosomal complements of the key founders of the main Solanaceae clades and the rearrangements that led to the karyotypes of extant species and their ancestors. From 10% to 15% of the genes present in the four genomes were syntenic paralogs (ohnologs) generated by the pre-γ, γ and T paleopolyploidy events, and were enriched in transcription factors. Our data suggest that the basic gene network controlling fruit ripening is conserved in different Solanaceae clades, and that climacteric fruit ripening involves a differential regulation of relatively few components of this network, including CNR and ethylene biosynthetic genes.
L. (eggplant) bacterial wilt is a severe soil borne disease. Here, this study aimed to explore the regulation mechanism of eggplant bacterial wilt-resistance by transcriptomics with weighted gene ...co-expression analysis network (WGCNA). The different expression genes (DEGs) of roots and stems were divided into 21 modules. The module of interest (root: indianred4, stem: coral3) with the highest correlation with the target traits was selected to elucidate resistance genes and pathways. The selected module of roots and stems co-enriched the pathways of MAPK signalling pathway, plant pathogen interaction, and glutathione metabolism. Each top 30 hub genes of the roots and stems co-enriched a large number of receptor kinase genes. A total of 14 interesting resistance-related genes were selected and verified with quantitative polymerase chain reaction (qPCR). The qPCR results were consistent with those of WGCNA. The hub gene of
(namely
) was further functionally verified;
positively regulated the resistance of eggplant to bacterial wilt by qPCR and virus-induced gene silencing (VIGS). Our study provides a reference for the interaction between eggplants and bacterial wilt and the breeding of broad-spectrum and specific eggplant varieties that are bacterial wilt-resistant.
DNA methylation through the activity of cytosine-5-methyltransferases (C5-MTases) and DNA demethylases plays important roles in genome protection as well as in regulating gene expression during plant ...development and plant response to environmental stresses. In this study, we report on a genome-wide identification of six C5-MTases (SmelMET1, SmelCMT2, SmelCMT3a, SmelCMT3b, SmelDRM2, SmelDRM3) and five demethylases (SmelDemethylase_1, SmelDemethylase_2, SmelDemethylase_3, SmelDemethylase_4, SmelDemethylase_5) in eggplant. Gene structural characteristics, chromosomal localization and phylogenetic analyses are also described. The transcript profiling of both C5-MTases and demethylases was assessed at three stages of fruit development in three eggplant commercial F1 hybrids: i.e. 'Clara', 'Nite Lady' and 'Bella Roma', representative of the eggplant berry phenotypic variation. The trend of activation of C5-MTases and demethylase genes varied in function of the stage of fruit development and was genotype dependent. The transcription pattern of C5MTAses and demethylases was also assessed in leaves of the F1 hybrid 'Nite Lady' subjected to salt and drought stresses. A marked up-regulation and down-regulation of some C5-MTases and demethylases was detected, while others did not vary in their expression profile. Our results suggest a role for both C5-MTases and demethylases during fruit development, as well as in response to abiotic stresses in eggplant, and provide a starting framework for supporting future epigenetic studies in the species.
Anthocyanin synthesis is affected by many factors, among which temperature is an important environmental factor. Eggplant is usually exposed to high temperatures during the cultivation season in ...Shanghai, China. Therefore,RNA -seq analysis was used to determine the effects of high-temperature stress on gene expression in the anthocyanin biosynthetic pathway of eggplant (Solanum melongena L.).
We tested the heat-resistant cultivar 'Tewangda'. The plants were incubated at 38 °C and 45 °C, and the suitable temperature for eggplant growth was used as a control. The treatment times were 3 h and 6 h. The skin of the eggplant was taken for transcriptome sequencing, qRT-PCR assays and bioinformatic analysis. The results showed that 770 genes were differentially expressed between different treatments. Gene Ontology (GO) database and Kyoto Encyclopedia of Genes and Genomes (KEGG) database analyses identified 16 genes related to anthocyanin biosynthesis, among which CHSB was upregulated. Other genes, including BHLH62, MYB380, CHI3, CHI, CCOAOMT, AN3, ACT-2, HST, 5MA-T1, CYP75A2, ANT17, RT, PAL2, and anthocyanin 5-aromatic acyltransferase were downregulated. In addition, the Myb family transcription factor PHL11 was upregulated in the CK 3 h vs 45 °C 3 h, CK 3 h vs 38 °C 3 h, and CK 6 h vs 38 °C 6 h comparisons, and the transcription factor bHLH35 was upregulated in the CK 3 h vs 38 °C 3 h and CK 6 h vs 38 °C 6 h comparisons.
These results indicated that high temperature will downregulate most of the genes in the anthocyanin biosynthetic pathway of eggplant. Our data have a reference value for the heat resistance mechanism of eggplant and can provide directions for molecular breeding of heat-resistant germplasm with anthocyanin content in eggplant.
Hydroponic experiments were conducted to investigate an effect of exogenous application of proline (Pro; 25µM) in alleviating arsenate (AsV; 5 and 25µM) toxicity in Solanum melongena L. (eggplant) ...seedlings. Exposure of AsV declined growth of eggplant, which was coincided with an enhanced accumulation of As. However, exogenous Pro application alleviated AsV toxicity in eggplant seedlings by reducing the accumulation of As. The fluorescence characteristics (JIP-test): φP0, Ψ0, φE0, PIABS, ABS/RC, TR0/RC, ET0/RC, DI0/RC, NPQ and qP were also affected by AsV. However, the effects of AsV were more prominent on PIABS DI0/RC and NPQ. In Pro treated seedlings, following parameters viz. φP0, Ψ0, φE0 and PIABS were stimulated, while, energy flux parameters (ABS/RC, TR0/RC, ET0/RC and DI0/RC) were inhibited. Toxic effects of AsV on photochemistry of photosystem II (PS II) were ameliorated by an exogenous application of Pro. Oxidative stress markers: superoxide radical, hydrogen peroxide and malondialdehyde (lipid peroxidation) were enhanced by AsV exposure, however, their levels were significantly diminished by an exogenous application of Pro. Treatment of AsV stimulated the activities of superoxide dismutase, peroxidase and catalase except that of glutathione-S-transferase. Exogenous Pro application improved the activities of enzymatic antioxidants. The level of endogenous Pro was higher in AsV treated as well as in Pro fed seedlings. The activity of a key enzyme of Pro biosynthesis: Δ1-pyrroline-5-carboxylate synthetase was higher in Pro fed seedlings. The activity of Pro dehydrogenase was inhibited under AsV stress, and its activity was minimum in case of Pro+AsV combination. These results indicate that Pro metabolism could play a key role in regulating the accumulation of As and levels of antioxidants, which concomitantly result into a better growth of eggplant seedlings when compared to the AsV treatments alone.
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•AsV exerts toxic effects on Sonalum melongena L. seedlings.•This occurred due to enhanced uptake of AsV ultimately leading to oxidative stress.•Exogenous Pro protects S. melongena against AsV toxicity.•Pro-mediated amelioration of As toxicity is due to decline in AsV uptake, and up-regulation of defense system of S. melongena.•Pro metabolism could play a role in AsV tolerance.
Increasing the content in bioactive phenolics in the eggplant (Solanum melongena) fruit is of interest, but may result in enhanced browning. We evaluated six varieties of S. melongena, 22 accessions ...of wild related species and 42 interspecific hybrids between cultivated eggplant and wild relatives for phenolics content, fruit flesh colour, polyphenol oxidase (PPO) activity, and fruit flesh browning. Wild relatives generally had a higher content in phenolics and a broader range of variation than cultivated eggplant. Chlorogenic acid was the predominant (>65.0%) phenolic acid in cultivated eggplant and its primary genepool wild ancestor S. insanum, while for the other wild species on average represented <50% of the chromatogram peak area. Fruit flesh colour was lighter in S. melongena than in the wild species, while PPO activity and browning was much higher in wild species of the secondary and tertiary genepools. Interspecific hybrids between S. melongena and S. insanum were intermediate in their characteristics, while those with secondary and tertiary genepool species were more similar to the wild species. No significant correlations were found between total phenolics or chlorogenic acid contents and fruit flesh browning, but PPO activity was correlated to both the degree of browning (r=0.404) and colour difference (r=0.458). The results indicate that wild species can contribute to improving the bioactive properties of eggplant without affecting negatively fruit flesh colour and browning.
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•Phenolics content and browning are variable in eggplant, wild relatives and hybrids.•Most wild relatives had high phenolics content, PPO activity and browning.•Interspecific hybrid characteristics were intermediate or closer to the wild parent.•PPO activity, but not phenolics, was correlated to fruit flesh browning.•Wild species can contribute to breeding for phenolics concentration in eggplant.
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