Project description:Brassinosteroids (BRs) are steroidal plant hormones essential for normal plant growth and development. Mutants in the biosynthesis or perception of BRs are usually dwarf. The tomato Dwarf gene (D), which was predicted to encode a cytochrome P450 enzyme (P450) with homology to other P450s involved in BR biosynthesis, was cloned previously. Here, we show that DWARF catalyses the C-6 oxidation of 6-deoxocastasterone (6-deoxoCS) to castasterone (CS), the immediate precursor of brassinolide. To do this, we first confirmed that the D cDNA complemented the mutant light- and dark-grown phenotypes of the extreme dwarf (dx) allele of tomato. To identify a substrate for the DWARF enzyme, exogenous application of BR intermediates to dx plants was carried out. C-6 oxoBR intermediates enhanced hypocotyl elongation whereas the C-6 deoxoBR, 6-deoxoCS, had little effect. Quantitative analysis of endogenous BR levels in tomato showed mainly the presence of 6-deoxoBRs. Furthermore, dx plants were found to lack CS and had a high level of 6-deoxoCS in comparison to D plants that had CS and a lower level of 6-deoxoCS. Confirmation that DWARF catalyzed the C-6 oxidation of 6-deoxoCS to CS was obtained by functional expression of DWARF in yeast. In these experiments, the intermediate 6alpha-hydroxycastasterone was identified, indicating that DWARF catalyzes two steps in BR biosynthesis. These data show that DWARF is involved in the C-6 oxidation in BR biosynthesis.
Project description:In the summer, the high temperatures, high humidity, frequent rainstorms, and typhoons in the East China region limit the growth of SAOPOLO tomato seedlings. By using a plant factory combined with an LED artificial light environment, the light environment can be effectively controlled to produce high-quality seedlings. This study investigates the growth and energy consumption of tomato seedlings in an artificial light plant factory. The experiment compared tomato seedlings cultivated in the artificial LED light environment of a plant factory with those grown in a semi-enclosed seedling greenhouse. The study meticulously examined the actual growth and development processes of the tomato seedlings, systematically tracking and recording the specific impacts of different cultivation environments on the seedlings' growth and development. Additionally, the experiment followed up on the fruiting conditions of the subsequent tomato plants. The experimental results show that compared to tomato seedlings grown in a greenhouse, those cultivated in the artificial light plant factory grew more slowly before grafting, characterized by slightly lower plant height, relatively smaller leaf area, and slightly thinner stems. However, after grafting, the growth rate of the tomato seedlings in the plant factory significantly accelerated, with increased plant height, leaf area, and stem diameter. On the 16th day after grafting, the cumulative leaf length and width fitting curves for the two cultivation methods coincided. Furthermore, it is noteworthy that the electricity consumption during the tomato seedling cultivation process, including that for controlling environmental temperature and humidity and the LED artificial supplemental lighting in the plant factory, was significantly lower. Over the two-month seedling cultivation period, the resource consumption in the greenhouse was 220% and 281% higher than in the plant factory, respectively. Statistical results also showed that the mortality rate of tomato seedlings cultivated in the artificial light plant factory was only 4.3%, much lower than the 6.5% mortality rate in the greenhouse. When the subsequent tomato plants were uniformly transplanted to the greenhouse for cultivation and their fruit weights were measured and recorded, the results indicated no significant difference in the fruit weights of tomatoes grown in the plant factory compared to those grown in the greenhouse. Therefore, experimental evidence confirms that cultivating tomato seedlings in an artificial light plant factory can significantly reduce cultivation costs, increase seedling survival rates, and not affect tomato quality.
Project description:Modern plant breeding heavily relies on the use of molecular markers. In recent years, next generation sequencing (NGS) emerged as a powerful technology to discover DNA sequence polymorphisms and generate molecular markers very rapidly and cost effectively, accelerating the plant breeding programmes. A single dominant locus, Frl, in tomato provides resistance to the fungal pathogen Fusarium oxysporum f. sp. radicis-lycopersici (FORL), causative agent of Fusarium crown and root rot. In this study, we describe the generation of molecular markers associated with the Frl locus. An F2 mapping population between an FORL resistant and a susceptible cultivar was generated. NGS technology was then used to sequence the genomes of a susceptible and a resistant parent as well the genomes of bulked resistant and susceptible F2 lines. We zoomed into the Frl locus and mapped the locus to a 900 kb interval on chromosome 9. Polymorphic single-nucleotide polymorphisms (SNPs) within the interval were identified and markers co-segregating with the resistant phenotype were generated. Some of these markers were tested successfully with commercial tomato varieties indicating that they can be used for marker-assisted selection in large-scale breeding programmes.
Project description:Tomato Genomic Resources Database (TGRD) allows interactive browsing of tomato genes, micro RNAs, simple sequence repeats (SSRs), important quantitative trait loci and Tomato-EXPEN 2000 genetic map altogether or separately along twelve chromosomes of tomato in a single window. The database is created using sequence of the cultivar Heinz 1706. High quality single nucleotide polymorphic (SNP) sites between the genes of Heinz 1706 and the wild tomato S. pimpinellifolium LA1589 are also included. Genes are classified into different families. 5'-upstream sequences (5'-US) of all the genes and their tissue-specific expression profiles are provided. Sequences of the microRNA loci and their putative target genes are catalogued. Genes and 5'-US show presence of SSRs and SNPs. SSRs located in the genomic, genic and 5'-US can be analysed separately for the presence of any particular motif. Primer sequences for all the SSRs and flanking sequences for all the genic SNPs have been provided. TGRD is a user-friendly web-accessible relational database and uses CMAP viewer for graphical scanning of all the features. Integration and graphical presentation of important genomic information will facilitate better and easier use of tomato genome. TGRD can be accessed as an open source repository at http://59.163.192.91/tomato2/.
Project description:Studies have shown that dwarf plants have the potential for use in obtaining hybrids. The aim of this study was to evaluate the agronomic potential and genetic dissimilarity of saladette type dwarf tomato plant populations through the use of artificial neural networks (ANNs). The following traits were analyzed: mean fruit weight, transverse and longitudinal fruit diameter, fruit shape, pulp thickness, locule number, internode length, soluble solids content, and β-carotene, lycopene, and leaf zingiberene contents. A dendrogram obtained by the unweighted pair-group method with arithmetic mean (UPGMA) and Kohonen self-organizing maps (SOM) agreed in the distinction of the BC1F3 populations from the dwarf donor parent. SOM was more consistent in identifying the genetic similarities among the BC1F3 dwarf tomato plant populations and allowed for the determination of weights of each variable in the cluster formation. The UFU SDi 13-1 BC1F3 population was revealed to be a promising option for obtaining saladette type dwarf tomato plant lines.
Project description:The effect of carrageenans on tomato chlorotic dwarf viroid (TCDVd) replication and symptom expression was studied. Three-week-old tomato plants were spray-treated with iota(ɩ)-, lambda(λ)-, and kappa(κ)-carrageenan at 1 g·L-1 and inoculated with TCDVd after 48 h. The λ-carrageenan significantly suppressed viroid symptom expression after eight weeks of inoculation, only 28% plants showed distinctive bunchy-top symptoms as compared to the 82% in the control group. Viroid concentration was reduced in the infected shoot cuttings incubated in λ-carrageenan amended growth medium. Proteome analysis revealed that 16 tomato proteins were differentially expressed in the λ-carrageenan treated plants. Jasmonic acid related genes, allene oxide synthase (AOS) and lipoxygenase (LOX), were up-regulated in λ-carrageenan treatment during viroid infection. Taken together, our results suggest that λ-carrageenan induced tomato defense against TCDVd, which was partly jasmonic acid (JA) dependent, and that it could be explored in plant protection against viroid infection.
Project description:Brassinosteroids (BRs) play a critical role in plant growth, development and stress response; however, genetic evidence for the BR-mediated integrated regulation of plant growth still remains elusive in crop species. Here, we clarified the function of DWARF (DWF), the key BR biosynthetic gene in tomato, in the regulation of plant growth and architecture, phytohormone homeostasis and fruit development by comparing wild type, d^(im), a weak allele mutant impaired in DWF, and DWF-overexpressing plants in tomato. Results showed that increases in DWF transcripts and endogenous BR level resulted in improved germination, lateral root development, CO2 assimilation and eventually plant growth as characterized by slender and compact plant architecture. However, an increase in DWF transcript down-regulated the accumulation of gibberellin, which was associated with decreases in leaf size and thickness. BRs positively regulated lateral bud outgrowth, which was associated with decreased transcript of Aux/IAA3, and the ethylene-dependent petiole bending and fruit ripening. Notably, overexpression of DWF did not significantly alter fruit yield per plant; however, increases by 57.4% and 95.3% might be estimated in fruit yield per square metre in two transgenic lines due to their compact architecture. Significantly, BR level was positively related with the carotenoid accumulation in the fruits. Taken together, our results demonstrate that BRs are actively involved in the regulation of multiple developmental processes relating to agronomical important traits.
Project description:Plant factories are an advanced form of facility agriculture that enable efficient plant cultivation through controllable environmental conditions, making them highly suitable for the automation and intelligent application of machinery. Tomato cultivation in plant factories has significant economic and agricultural value and can be utilized for various applications such as seedling cultivation, breeding, and genetic engineering. However, manual completion is still required for operations such as detection, counting, and classification of tomato fruits, and the application of machine detection is currently inefficient. Furthermore, research on the automation of tomato harvesting in plant factory environments is limited due to the lack of a suitable dataset. To address this issue, a tomato fruit dataset was constructed for plant factory environments, named as TomatoPlantfactoryDataset, which can be quickly applied to multiple tasks, including the detection of control systems, harvesting robots, yield estimation, and rapid classification and statistics. This dataset features a micro tomato variety and was captured under different artificial lighting conditions, including changes in tomato fruit, complex lighting environment changes, distance changes, occlusion, and blurring. By facilitating the intelligent application of plant factories and the widespread adoption of tomato planting machinery, this dataset can contribute to the detection of intelligent control systems, operation robots, and fruit maturity and yield estimation. The dataset is publicly available for free and can be utilized for research and communication purposes.
Project description:Tomato brown rugose fruit virus (ToBRFV) is an emerging and rapidly spreading RNA virus that infects tomato and pepper, with tomato as the primary host. The virus causes severe crop losses and threatens tomato production worldwide. ToBRFV was discovered in greenhouse tomato plants grown in Jordan in spring 2015 and its first outbreak was traced back to 2014 in Israel. To date, the virus has been reported in at least 35 countries across four continents in the world. ToBRFV is transmitted mainly via contaminated seeds and mechanical contact (such as through standard horticultural practices). Given the global nature of the seed production and distribution chain, and ToBRFV's seed transmissibility, the extent of its spread is probably more severe than has been disclosed. ToBRFV can break down genetic resistance to tobamoviruses conferred by R genes Tm-1, Tm-2, and Tm-22 in tomato and L1 and L2 alleles in pepper. Currently, no commercial ToBRFV-resistant tomato cultivars are available. Integrated pest management-based measures such as rotation, eradication of infected plants, disinfection of seeds, and chemical treatment of contaminated greenhouses have achieved very limited success. The generation and application of attenuated variants may be a fast and effective approach to protect greenhouse tomato against ToBRFV. Long-term sustainable control will rely on the development of novel genetic resistance and resistant cultivars, which represents the most effective and environment-friendly strategy for pathogen control.TaxonomyTomato brown rugose fruit virus belongs to the genus Tobamovirus, in the family Virgaviridae. The genus also includes several economically important viruses such as Tobacco mosaic virus and Tomato mosaic virus.Genome and virionThe ToBRFV genome is a single-stranded, positive-sense RNA of approximately 6.4 kb, encoding four open reading frames. The viral genomic RNA is encapsidated into virions that are rod-shaped and about 300 nm long and 18 nm in diameter. Tobamovirus virions are considered extremely stable and can survive in plant debris or on seed surfaces for long periods of time.Disease symptomsLeaves, particularly young leaves, of tomato plants infected by ToBRFV exhibit mild to severe mosaic symptoms with dark green bulges, narrowness, and deformation. The peduncles and calyces often become necrotic and fail to produce fruit. Yellow blotches, brown or black spots, and rugose wrinkles appear on tomato fruits. In pepper plants, ToBRFV infection results in puckering and yellow mottling on leaves with stunted growth of young seedlings and small yellow to brown rugose dots and necrotic blotches on fruits.
Project description:The breeding improvement of triticale is tightly associated with the introgression of dwarfing genes, in particular, gibberellin (GA)-insensitive Ddw1 from rye. Despite the increase in harvest index and resistance to lodging, this gene adversely affects grain weight and size. Growth regulation factor (GRF) genes are plant-specific transcription factors that play an important role in plant growth, including GA-induced stem elongation. This study presents the results of a two-year field experiment to assess the effect of alleles of the TaGRF3-2A gene in interaction with DDW1 on economically valuable traits of spring triticale plants grown in the Non-Chernozem zone. Our results show that, depending on the allelic state, the TaGRF3-2A gene in semi-dwarf spring triticale plants influences the thousand grain weight and the grain weight of the main spike in spring triticale, which makes it possible to use it to compensate for the negative effects of the dwarfing allele Ddw1. The identified allelic variants of the TaGRF3-2A gene can be included in marker-assisted breeding for triticale to improve traits.