Solanaceae Plants Research Articles

Molecular Characteristics of Subgenomic RNAs and the Cap-Dependent Translational Advantage Relative to Corresponding Genomic RNAs of Tomato spotted wilt virus

Tomato spotted wilt virus (TSWV) causes severe viral diseases on many economically important plants of Solanaceae. During the infection process of TSWV, a series of 3'-truncated subgenomic RNAs (sgRNAs) relative to corresponding genomic RNAs were synthesized, which were responsible for the expression of some viral proteins. However, corresponding genomic RNAs (gRNAs) seem to possess the basic elements for expression of these viral proteins. In this study, molecular characteristics of sgRNAs superior to genomic RNAs in viral protein expression were identified. The 3' ends of sgRNAs do not cover the entire intergenic region (IGR) of TSWV genomic RNAs and contain the remarkable A-rich characteristics. In addition, the 3' terminal nucleotides of sgRNAs are conserved among different TSWV isolates. Based on the eIF4E recruitment assay and subsequent northern blot, it is suggested that the TSWV sgRNA, but not gRNA, is capped in vivo; this is why sgRNA is competent for protein expression relative to gRNA. In addition, the 5' and 3' untranslated region (UTR) of sgRNA-Ns can synergistically enhance cap-dependent translation. This study further enriched the understanding of sgRNAs of ambisense RNA viruses.

The role of salivary proteins from Tetranychus evansi in the mite-plant interaction

Herbivores and plants have been engaged in a tight co-evolutionary arms race, and saliva played important roles in this process. Some herbivore-derived small molecules or proteins called herbivore-associated molecular patterns (HAMPs) can be recognized by plants and thus trigger plant immune responses. Another type of salivary proteins, called effectors, utilize various strategies to suppress plant defense responses to establish successful feeding. The tomato red spider mite Tetranychus evansi is a worldwide pest of Solanaceous crops and causes enormous economic damage in many regions of the world. During the feeding process, T. evansi secretes saliva into plant cells through cheliceral stylets. Secreted saliva plays crucial roles in modulating plant-mite interaction, such as effectors Te28 and Te84 (Villarroel et al., 2016). We previously identified 136 salivary proteins from T. evansi by transcriptome and LC-MS/MS analyses (Huang et al., 2018). However, the role of these salivary proteins in mite-plant interaction was unknown. Here, we identified a salivary protein involved in the mite-plant interaction (Cui et al., 2022). This protein encodes a protein disulfide isomerase (TePDI) and acts as a HAMP that triggers plant defenses by inducing ROS burst, callose deposition and plant defense-related genes in Nicotiana benthamiana. TePDI can be recognized by multiple Solanaceae plants such as tomato, pepper, and eggplant. TePDI-mediated cell death in N. benthamiana is dependent on the plant signaling molecules SGT1 (suppressor of the G2 allele of skp1) and HSP90 (heat shock protein 90). To better feed on plants, T. evansi inhibited TePDI-triggered cell death and plant defense responses by secreting effectors Te28 and Te84. Further analysis revealed that PDI from phylogenetically distinct herbivorous and non-herbivorous arthropods all triggered cell death and immune response in N. benthamiana. Moreover, silencing PDI gene in spider mites and whiteflies resulted in the reduced survival rate of both pests. Altogether, our study revealed that PDI is a double-edged sword. On the one hand, it is functionally conserved in herbivores and required for their survival; on the other hand, it is recognized by Solanaceae plants and enhances plant resistance against herbivores. Our findings indicate that plants utilize evolutionarily conserved HAMPs to activate plant defense and resist pest damage, providing a potential strategy for pest management.

Landscape and evolutionary dynamics of Helitron transposons in plant genomes as well as construction of online database HelDB

AbstractHelitron transposons play an important role in host genome evolution due to their ability to capture genes and regulatory elements. In this study, we developed a pipeline to identify and annotate Helitrons systematically from 358 plant and 178 animal high‐quality genomes. All these data were organized into HelDB, a database where Helitrons can be explored with a user‐friendly Web interface and related software. Based on these data, further analysis showed that the number or the cumulative length of Helitrons is positively correlated with genome size. Helitrons had experienced two expansion periods in plants, with the first occurring 20–30 Ma and peaking at approximately 24 Ma. The second expansion occurred in the last 4 million years. The expansions might be due to stimulation of paleogeographic environment. Detailed investigation of gene capture by Helitrons in Brassicaceae and Solanaceae plants showed that the captured genes showed diverse functions. Interestingly, metal ion binding function was enriched in these captured genes in most species. This phenomenon might be due to the need for binding of divalent metal ions to the Rep domain required for Helitron transposition. This study improves our knowledge of the landscape and evolution of Helitron transposons in plants and paves a way for further functional studies of this kind of transposable element.

Silencing of a mannitol transport gene in Phelipanche aegyptiaca by the tobacco rattle virus system reduces the parasite germination on the host root

ABSTRACT Root parasitic weed Phelipanche aegyptiaca is an obligate plant parasite that causes severe damage to host crops. Agriculture crops mainly belong to the Brassicaceae, Leguminosae, Cruciferae, and Solanaceae plant families affected by this parasitic weed, leading to the devastating loss of crop yield and economic growth. This root-specific parasitic plant is not able to complete its life cycle without a suitable host and is dependent on the host plant for nutrient uptake and germination. Therefore, selected parasitic genes of P. aegyptiaca which were known to be upregulated upon interaction with the host were chosen. These genes are essential for parasitism, and reduced activity of these genes could affect host-parasitic interaction and provide resistance to the host against these parasitic weeds. To check and examine the role of these parasitic genes which can affect the development of host resistance, we silenced selected genes in the P. aegyptiaca using the tobacco rattle virus (TRV) based virus-induced gene silencing (VIGS) method. Our results demonstrated that the total number of P. aegyptiaca parasite tubercles attached to the root of the host plant Nicotiana benthamiana was substantially decreased in all the silenced plants. However, silencing of the P. aegyptiaca MNT1 gene which encodes the mannitol transporter showed a significantly reduced number of germinated shoots and tubercles. Thus, our study indicates that the mannitol transport gene of P. aegyptiaca plays a crucial role in parasitic germination, and silencing of the PaMNT1 gene abolishes the germination of parasites on the host roots.

Gene expression analysis of the ATP-binding cassette transporter ABCD1 in petunia (Petunia hybrida) and tobacco (Nicotiana spp.)

Most plant metabolites are biosynthesized via organelles, including peroxisome. From the mutant analyses, Arabidopsis ATP-binding cassette (ABC) transporter ABCD1 is reported to be implicated in the peroxisomal import of β-oxidation substrates, which are biosynthetic intermediates for central and specialized metabolites. However, little was explored about ABCD1 in plants except for AtABCD1 and two barley homologs, HvABCD1 and 2. The present study investigated the expression profiles of ABCD1 genes of petunia and tobacco that produce various metabolites, including volatile benzenoid/phenylpropanoids (VBPs) and ubiquinone. PhABCD1 expression was ubiquitous and at particularly high levels (2.2- to 2.8-fold compared to roots) in leaves, limbs, and tubes. NsABCD1 was expressed in roots, stems, leaves, sepals, and flowers; specifically, a relatively high expression level (3.2-fold compared to roots) was observed in sepals. Yeast extract and methyl jasmonate induced the expression of the NtABCD1 gene significantly (1.3- and 2.5-fold, respectively) in N. tabacum BY-2 cells. These results suggest that the expression of ABCD1 would be related to the biosynthesis of metabolites beneficial for plant environmental adaptation in petunia and tobacco. The current study provides new insights into the mechanism of metabolite biosynthesis and ABC transporter function in Solanaceae plants.

A conserved protein disulfide isomerase enhances plant resistance against herbivores.

Herbivore-associated molecular patterns (HAMPs) enable plants to recognize herbivores and may help plants adjust their defense responses. Here, we report on herbivore-induced changes in a protein disulfide isomerase (PDI) widely distributed across arthropods. PDI from the spider mite Tetranychus evansi (TePDI), a mesophyll-feeding agricultural pest worldwide, triggered immunity in multiple Solanaceae plants. TePDI-mediated cell death in Nicotiana benthamiana required the plant signaling proteins SGT1 (suppressor of the G2 allele of skp1) and HSP90 (heat shock protein 90), but was suppressed by spider mite effectors Te28 and Te84. Moreover, PDIs from phylogenetically distinct herbivorous and nonherbivorous arthropods triggered plant immunity. Finally, although PDI-induced plant defenses impaired the performance of spider mites on plants, RNAi experiments revealed that PDI genes are essential for the survival of mites and whiteflies. Our findings indicate that plants recognize evolutionarily conserved HAMPs to activate plant defense and resist pest damage, pointing to opportunities for broad-spectrum pest management.

Insights of ethyl acetate fraction from Vassobia breviflora in multidrug-resistant bacteria and cancer cells: from biological to therapeutic

ABSTRACT Cancer and infectious diseases are among the leading causes of death in the world. Despite the diverse array of treatments available, challenges posed by resistance, side effects, high costs, and inaccessibility persist. In the Solanaceae plant family, few studies with Vassobia breviflora species relating to biological activity are known, but promising results have emerged. The phytochemicals present in the ethyl acetate fraction were obtained using ESI-MS-QTOF, and the antioxidants assays 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radical capture (ABTS), plasma ferric reduction capacity (FRAP), and total antioxidant capacity (TAC). Cytotoxic activity was evaluated by MTT, Neutral Red, and lactate dehydrogenase (LDH) released. The production of reactive oxygen species, nitric oxide, and purinergic enzymes was also investigated. Antibacterial activity was measured through minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and antibiofilm activity, in addition to genotoxicity in plasmid DNA. Five major masses were identified D-glucopyranose II, allyl disulfide, γ-lactones, pharbilignoside, and one mass was not identified. V. breviflora exhibited relevant antioxidant and cytotoxic activity against the HeLa cell line and enhanced expression effect in modulation of purinergic signaling. Antibacterial activities in the assays in 7 ATCC strains and 8 multidrug-resistant clinical isolates were found. V. breviflora blocked biofilm formation in producing bacteria at the highest concentrations tested. However, there was no plasmid DNA cleavage at the concentrations tested. Data demonstrated that V. breviflora exhibited an antioxidant effect through several methods and proved to be a promising therapeutic alternative for use against tumor cells via purinergic signaling and multidrug-resistant microorganisms, presenting an anti-biofilm effect.

Glycoalkaloids of Plants in the Family Solanaceae (Nightshade) as Potential Drugs.

Worldwide interest in medicinal plants and related drugs is growing because of the increased spectrum of new synthetic drugs. In this context, secondary plant metabolites are most significant. This review analyzes data on the structures and biosyntheses of metabolites such as glycoalkaloids; methods for their extraction from plants of the family Solanaceae, particularly potato S. tuberosum; their qualitative and quantitative analysis; biological activity; and toxicity. This information could be useful in the selection of methods for sample preparation and extraction of glycoalkaloids during the search for new plant sources with prospects of creating effective and safe pharmacological agents.

THE DEVELOPMENTAL AND BIOCHEMICAL FEATURES OF LEISHMANIA DONOVANI PROMASTIGOTE AND THEIR REPRESSION BY DATURA STRAMONIUM PLANT EXTRACT

Leishmania is an intracellular digenetic obligate parasite spread by insects and poses grave health issues throughout the world. Extensive use of antimony compounds as drugs poses high toxicity and cost and therefore, a position has been identied for herbal medicine. This study has been carried out to explore the developmental biochemical characteristics of Leishmania donovani promastigote. In addition, the mode of action of Datura stramonium (Solanaceae) plant extract on promastigote form of leishmania have been examined. Friedman's repeated measures analysis showed that 96hr of development is the junction point in promastigotes ontogeny. Post 96hr, it grows with a long stationary phase with higher enzymatic activities viz., acid phosphatase, superoxide dismutase and glutathione (oxidized and reduced). Total protein estimated, showed a linear relationship (R2 = 0.999). Phytochemical screening of extracts showed the presence of alkaloid, avonoid, xed oil and fats, saponin, tannin and phenolic compounds etc, and showed an effectual free radical scavenging in the DPPH assay with an IC50 value of extract of D. stramonium (55.63 µg/ml). A concentration of 250 µg/mL of the plant extract completely inhibited the L. donovani promastigotes in vitro while concentrations of 50 µg/mL and 100 µg/mL decreased the survival level by 25-50%. Our ndings corroborate the ethnopharmacological use of this plant for the treatment of Leishmaniasis. Also, our results are promoters as potential sources to search antileishmanial bioactive agents.

The Differential Effects of Tuta absoluta Infestations on the Physiological Processes and Growth of Tomato, Potato, and Eggplant.

Simple SummaryOur study aimed to assess how Tuta absoluta affects different Solanaceae plant species. It was observed that susceptible plants experience diminished growth and reproduction rates, which may be a result of a physiological malfunction. Infestation by T. absoluta caused 100% crop loss to tomato plants, whereas significant yield reduction was observed for potato plants, and no significant feeding effect was observed for eggplant. The affected plants also experienced physiological impairments. This study is essential in that it demonstrates the differential risk of T. absoluta infestations on the production of the tested Solanaceae plant species.Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae) is a destructive insect pest toward crops and belongs to the Solanaceae family. Since it was first recorded in South Africa in 2016, the pest has spread extensively and caused tremendous damage to field and tunnel-grown tomato crops. This study aimed to investigate how T. absoluta affects the growth and physiology of three Solanaceae plant species: tomato, potato, and eggplant. These three crops were infested with L1 instar larvae, and their growth and physiology were assessed during insect feeding. The damage to the infested tomato host plant was severe, with T. absoluta destroying 100% of the plants. The tomato plants were distorted 15 days after infestation, that is, before the fruit set. For potato, the defoliation was moderate, but the infested plants produced fewer tubers compared to the uninfested host plants. Eggplant had fewer visible signs of feeding, resulting in no significant difference between the infested and uninfested host plants in terms of growth and physiological functions. Infested tomato and potato plants had stagnant growth, fewer and damaged leaves, a reduced chlorophyll content, a reduced photosynthesis rate, a poor transpiration rate, poor water conductance, and poor intercellular carbon dioxide concentrations. This study closes the knowledge gap on the morphological (growth) and physiological responses of different Solanaceae species to T. absoluta infestation, and it also demonstrates the differential risk of T. absoluta infestations in the production of tomato, potato, and eggplant.

Two different domain architectures generate structural and functional diversity among bZIP genes in the Solanaceae family.

The bZIP gene family is one of the largest transcription factor families and has important roles in plant growth, development, and stress responses. However, bZIP genes in the Solanaceae family have not been extensively investigated. Here, we conducted genome-wide re-annotation in nine Solanaceae species and Arabidopsis thaliana. We annotated 935 bZIP genes, including 107 (11%) that were newly identified. Structural analyses of bZIP genes in the Solanaceae family revealed that the bZIP domain displayed two types of architectures depending on the presence of an additional domain, suggesting that these architectures generate diversified structures and functions. Motif analyses indicated that the two types of bZIP genes had distinct sequences adjacent to the bZIP domain. Phylogenetic analyses suggested that the two types of bZIP genes distinctly evolved and ultimately adapted in different lineages. Transcriptome analyses in pepper (Capsicum annuum) and tomato (Solanum lycopersicum) revealed putative functional diversity between the two types of bZIP genes in response to various abiotic stresses. This study extensively updated bZIP gene family annotations and provided novel evolutionary and functional evidence for the role of bZIP genes in Solanaceae plants. Our findings provide evolutionary and functional characteristics of bZIP genes for a better understanding of their roles in Solanaceae plants.

Two divergent immune receptors of the allopolyploid Nicotiana benthamiana reinforce the recognition of a fungal microbe-associated molecular pattern VdEIX3.

The allotetraploid Solanaceae plant Nicotiana benthamiana contains two closely related receptor-like proteins (RLPs), NbEIX2 and NbRXEG1, which regulate the recognition of VdEIX3 and PsXEG1, respectively. VdEIX3, PsXEG1, and their homologs represent two types of microbe-associated molecular patterns (MAMPs) that are widespread in diverse pathogens. Here, we report that NbRXEG1 also participates in VdEIX3 recognition. Both eix2 and rxeg1 single mutants exhibited significantly impaired but not abolished ability to mediate VdEIX3-triggered immune responses, which are nearly abolished in eix2 rxeg1 double mutants. Moreover, a dominant negative mutant of eix2 that contains a 60 bp deletion failed to respond to VdEIX3 and could suppress VdEIX3-induced cell death in the wild-type N. benthamiana. Further phylogenetic analyses showed that NbEIX2 and NbRXEG1 are obtained from different diploid ancestors by hybridization. These results demonstrate that the allotetraploid N. benthamiana recognizes two types of MAMPs by two homologous but diverged RLPs, which provides a model in which an allopolyploid plant probably exhibits defense hybrid vigor by acquiring divergent immune receptors from different ancestors.

GRP genes in potato genome and their expression response to phytohormone and Ralstonia solanacearum

AbstractCell wall glycine‐rich proteins (GRPs) play important roles in plant growth and development, as well as in the effective prevention of plant diseases. Although members of the GRP family have been identified in several plants, a comprehensive analysis of GRPs has not been reported in Solanaceae plants. In this study, 43 GRPs were identified from Solanum tuberosum (named StGRPs), Solanum lycopersicum, Capsicum annuum and Nicotiana attenuata. The comparative study of these GRPs showed that they were conservative in physical properties, structures of genes and motifs. The expression patterns of Solanum tuberosum StGRPs under biotic and abiotic stress were analysed and presented very diverse profiles in responding to ABA, IAA, GA3, high salinity, pathogen and heat stress. Some StGRPs were preferentially and specifically expressed during the development of petioles and tubers, in which the expression of StGRPs was more sensitive to ABA confirmed by qRT‐PCR analysis. The strongly up‐regulated expression of StGRP1 induced by Ralstonia solanacearum indicated the positive role involved in the resistance against the bacterial wilt pathogen. Tissue localization analyses by Digoxin/fluorescence in situ hybridization indicated that the expression of StGRP1 was vascular‐specific and associated with cell wall thickening in vascular bundles and interfascicular fibres after R. solanacearum inoculation. These findings may provide a new insight into the roles of GRPs in adaptation to diverse stresses and in resistance to R. solanacearum in potatoes.

Habitat-adapted heterologous symbiont Salinispora arenicola promotes growth and alleviates salt stress in tomato crop plants.

To ensure food security given the current scenario of climate change and the accompanying ecological repercussions, it is essential to search for new technologies and tools for agricultural production. Microorganism-based biostimulants are recognized as sustainable alternatives to traditional agrochemicals to enhance and protect agricultural production. Marine actinobacteria are a well-known source of novel compounds for biotechnological uses. In addition, former studies have suggested that coral symbiont actinobacteria may support co-symbiotic photosynthetic growth and tolerance and increase the probability of corals surviving abiotic stress. We have previously shown that this activity may also hold in terrestrial plants, at least for the actinobacteria Salinispora arenicola during induced heterologous symbiosis with a wild Solanaceae plant Nicotiana attenuata under in vitro conditions. Here, we further explore the heterologous symbiotic association, germination, growth promotion, and stress relieving activity of S. arenicola in tomato plants under agricultural conditions and dig into the possible associated mechanisms. Tomato plants were grown under normal and saline conditions, and germination, bacteria-root system interactions, plant growth, photosynthetic performance, and the expression of salt stress response genes were analyzed. We found an endophytic interaction between S. arenicola and tomato plants, which promotes germination and shoot and root growth under saline or non-saline conditions. Accordingly, photosynthetic and respective photoprotective performance was enhanced in line with the induced increase in photosynthetic pigments. This was further supported by the overexpression of thermal energy dissipation, which fine-tunes energy use efficiency and may prevent the formation of reactive oxygen species in the chloroplast. Furthermore, gene expression analyses suggested that a selective transport channel gene, SlHKT1,2, induced by S. arenicola may assist in relieving salt stress in tomato plants. The fine regulation of photosynthetic and photoprotective responses, as well as the inhibition of the formation of ROS molecules, seems to be related to the induced down-regulation of other salt stress response genes, such as SlDR1A-related genes or SlAOX1b. Our results demonstrate that the marine microbial symbiont S. arenicola establishes heterologous symbiosis in crop plants, promotes growth, and confers saline stress tolerance. Thus, these results open opportunities to further explore the vast array of marine microbes to enhance crop tolerance and food production under the current climate change scenario.

Requirement of Myoglianin for metamorphosis in the beetle Henosepilachna vigintioctopunctata.

Henosepilachna vigintioctopunctata is a serious defoliating beetle attacking Solanaceae and Cucurbitaceae plants in many Asian countries. In the present paper, we identified a putative myoglianin (myo) gene. Hvmyo was actively transcribed throughout development, from embryo to adult. RNA interference (RNAi)-aided knockdown of Hvmyo delayed larval development by more than 2 days, reduced larval body size, inhibited the growth of antennae, wings and legs and disturbed gut purge. Knockdown of Hvmyo impaired the larval-pupal transition. All the Hvmyo RNAi larvae arrested at the larval stage or formed misshapen pupae or adults. The deformed pupae and adults were partially wrapped with exuviae, bearing separated wings. Moreover, the expression levels of five ecdysteroidogenesis genes (Hvspo, Hvphm, Hvdib, Hvsad and Hvshd), a prothocicotropic hormone (PTTH)/Torso pathway gene (Hvtorso), two 20E receptor genes (HvEcR and HvUSP), and two 20E signalling genes (HvE93 and HvFTZ-F1) were as a result of HvMyo RNAi significantly lowered. Conversely, the expression of a JH biosynthesis gene (Hvjhamt), a JH receptor gene HvMet and a JH signalling gene HvKr-h1 was greatly enhanced. Although ingestion of 20E and Hal rescued the 20E signal, it could not alleviate larval performance and defective phenotypes. Our results suggest that Myo exerts four distinctive roles in ecdysteroidogenesis, JH production, organ growth and larva-pupa-adult transformation in H. vigintioctopunctata.

MLO Proteins from Tomato (Solanum lycopersicum L.) and Related Species in the Broad Phylogenetic Context.

MLO proteins are a family of transmembrane proteins in land plants that play an important role in plant immunity and host–pathogen interactions, as well as a wide range of development processes. Understanding the evolutionary history of MLO proteins is important for understanding plant physiology and health. In the present work, we conducted a phylogenetic analysis on a large set of MLO protein sequences from publicly available databases, specifically emphasising MLOs from the tomato plant and related species. As a result, 4886 protein sequences were identified and used to construct a phylogenetic tree. In comparison to previous findings, we identified nine phylogenetic clades, revealed the internal structure of clades I and II as additional clades and showed the presence of monocotyledon species in all MLO clades. We identified a set of 19 protein motifs that allowed for the identification of particular clades. Sixteen SlMLO proteins from tomato were located in the phylogenetic tree and identified in relation to homologous sequences from other Solanaceae species. The obtained results could be useful for further work on the use of MLO proteins in the study of mildew resistance in Solanaceae and other plant families.

The complete chloroplast genome of the Egyptian henbane (Hyoscyamus muticus L., Solanaceae)

Egyptian henbane (Hyoscyamus muticus L. Mant. Pl. 1767) is an important medicinal plant of the family Solanaceae. Its complete chloroplast (cp) genome was assembled using Illumina high-throughput sequencing technology to contribute to its conservation genetics studies. Here, we report the complete sequence of the chloroplast genome of H. muticus. The cp genome was 156,271 bp in length with an asymmetric base composition (30.9% A, 18.9% C, 18.6% G and 31.6% T). It encodes 132 genes comprising 87 protein-coding genes, 29 tRNA genes, and 8 rRNA genes. The overall GC content of the H. muticus chloroplast genome was 37.5%, and the corresponding values in the large single-copy (LSC), the small single-copy (SSC), and the inverted repeat (IR) regions were 35.5%, 31.5%, and 43.0%, respectively. The complete chloroplast genome sequence was deposited to the GenBank (NCBI, Accession number: MZ450974). The maximum likelihood phylogenetic analysis showed that the H. muticus and H. niger were clustered into one clade with strong support values, indicating their closer relationship.

Identification of BAHD acyltransferases associated with acylinositol biosynthesis in Solanum quitoense (naranjilla).

Plants make a variety of specialized metabolites that can mediate interactions with animals, microbes, and competitor plants. Understanding how plants synthesize these compounds enables studies of their biological roles by manipulating their synthesis in vivo as well as producing them in vitro. Acylsugars are a group of protective metabolites that accumulate in the trichomes of many Solanaceae family plants. Acylinositol biosynthesis is of interest because it appears to be restricted to a subgroup of species within the Solanum genus. Previous work characterized a triacylinositol acetyltransferase involved in acylinositol biosynthesis in the Andean fruit plant Solanum quitoense (lulo or naranjilla). We characterized three additional S. quitoense trichome expressed enzymes and found that virus‐induced gene silencing of each caused changes in acylinositol accumulation. pH was shown to influence the stability and rearrangement of the product of ASAT1H and could potentially play a role in acylinositol biosynthesis. Surprisingly, the in vitro triacylinositol products of these enzymes are distinct from those that accumulate in planta. This suggests that additional enzymes are required in acylinositol biosynthesis. These characterized S. quitoense enzymes, nonetheless, provide opportunities to test the biological impact and properties of these triacylinositols in vitro.

Advances in S gene targeted genome-editing and its applicability to disease resistance breeding in selected Solanaceae crop plants

ABSTRACT Genome-editing tools for the development of traits to tolerate abiotic and biotic adversaries are the recently devised breeding techniques revolutionizing molecular breeding by addressing the issues of rapidness and precision. To that end, disease resistance development by disrupting disease susceptibility genes (S genes) to intervene in the biological mechanism of pathogenicity has significantly improved the techniques of molecular breeding. Despite the achievements in genome-editing aimed at the intervention of the function of susceptibility determinants or gene regulatory elements, off-target effects associated with yield-related traits are still the main setbacks. The challenges are attributed to the complexity of the inheritance of traits controlled by pleiotropic genes. Therefore, a more rigorous genome-editing tool with ultra-precision and efficiency for the development of broad-spectrum and durable disease resistance applied to staple crop plants is of critical importance in molecular breeding programs. The main objective of this article is to review the most impressive progresses achieved in resistance breeding against the main diseases of three Solanaceae crops (potato, Solanum tuberosum; tomato, Solanum lycopersicum and pepper, Capsicum annuum) using genome-editing by disrupting the sequences of S genes, their promoters, or pathogen genes. In this paper, we discussed the complexity and applicability of genome-editing tools, summarized the main disease of Solanaceae crops, and compiled the recent reports on disease resistance developed by S-gene silencing and their off-target effects. Moreover, GO count and gene annotation were made for pooled S-genes from biological databases. Achievements and prospects of S-gene-based next-generation breeding technologies are also discussed.

Not Only Systemin: Prosystemin Harbors Other Active Regions Able to Protect Tomato Plants

Prosystemin is a 200-amino acid precursor expressed in Solanaceae plants which releases at the C-terminal part a peptidic hormone called Systemin in response to wounding and herbivore attack. We recently showed that Prosystemin is not only a mere scaffold of Systemin but, even when deprived of Systemin, is biologically active. These results, combined with recent discoveries that Prosystemin is an intrinsically disordered protein containing disordered regions within its sequence, prompted us to investigate the N-terminal portions of the precursor, which contribute to the greatest disorder within the sequence. To this aim, PS1-70 and PS1-120 were designed, produced, and structurally and functionally characterized. Both the fragments, which maintained their intrinsic disorder, were able to induce defense-related genes and to protect tomato plants against Botrytis cinerea and Spodoptera littoralis larvae. Intriguingly, the biological activity of each of the two N-terminal fragments and of Systemin is similar but not quite the same and does not show any toxicity on experimental non-targets considered. These regions account for different anti-stress activities conferred to tomato plants by their overexpression. The two N-terminal fragments identified in this study may represent new promising tools for sustainable crop protection.