A single-base deletion mutation in <Emphasis Type="Italic">SlIAA9</Emphasis> gene causes tomato (<Emphasis Type="Italic">Solanum lycopersicum</Emphasis>) <Emphasis Type="Italic">entire</Emphasis> mutant

The entire (e) locus of tomato (Solanum lycopersicum L.) controls leaf morphology. Dominant E and recessive e allele of the locus produce pinnate compound and complex reduced leaves. Previous research had indicated that SlIAA9, an Aux/IAA gene, was involved in tomato leaf morphology. Down-regulation of SlIAA9 gene by antisense transgenic method decreased the leaf complex of tomato and converted tomato compound leaves to simple leaves. The leaf morphology of these transgenic lines was similar with leaf morphology of tomato entire mutant. In this paper, we report that a single-base deletion mutation in the coding region of SlIAA9 gene results in tomato entire mutant phenotypes.     

<Emphasis Type="Italic">Galleria</Emphasis><Emphasis Type="Italic">mellonella</Emphasis> are Resistant to <Emphasis Type="Italic">Pneumocystis</Emphasis><Emphasis Type="Italic">murina</Emphasis> Infection

Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner. The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate larvae Galleria mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host.     

Flight behavior and oviposition of <Emphasis Type="Italic">Tuta absoluta</Emphasis> on susceptible and resistant genotypes of <Emphasis Type="Italic">Solanum lycopersicum</Emphasis>

Plants produce volatile chemical compounds that can negatively affect the preference (antixenosis) or the performance (antibiosis) of herbivorous insects. It is thought that these volatile compounds are used as cues by herbivorous insects to determine the suitability of the plant for egg deposition and, hence, offspring performance. Here, we investigated whether volatiles produced by tomato plants play a role in modulating the flight and oviposition behavior of mated Tuta absoluta females. We found that the behavioral steps displayed by mated females did not differ when they flew toward resistant or susceptible tomato genotypes, but they reached the susceptible genotypes faster than the resistant ones. Moreover, females landed more often and laid more eggs on the most susceptible genotype, the Santa Clara variety. Because this variety is known to be of high quality for the development of T. absoluta larvae, the female’s decision to land and lay more eggs on this genotype seems to be mainly to maximize offspring performance. However, this is not so straightforward because the proportion of landings and eggs laid by T. absoluta on another susceptible genotype tested in this study was not significantly higher than on the resistant genotypes. Finally, although future studies are still needed, considering the antixenotic and antibiotic traits of the resistant genotypes studied here, they are likely to succeed if used in integrated pest management.     

Genetic Characterization of a New Growth Habit Mutant in Tomato (<Emphasis Type="Italic">Solanum lycopersicum</Emphasis>)

A mutant tomato cultivar (HT10-3-2) with indeterminate growth habit was obtained from a cultivar (T10-3-2) with determinate growth habit. The character of indeterminate growth habit in HT10-3-2 could be inherited stably. Unlike other normal growth habit cultivars, which are controlled by the SELF PRUNING gene, it was shown here that HT10-3-2 has no mutation in the sp gene. Two hundred random amplified polymorphic DNA (RAPD) primers were used to screen for polymorphism between the two genotypes from genomic DNA, and a polymorphic fragment (S168₁₄₅₈) was obtained and subsequently sequenced. However, Basic Local Alignment Search Tool searches indicated that the sequence of this RAPD fragment shares no significant homology with known sequences in GenBank. The RAPD marker (S168₁₄₅₈) was converted to a sequence characterized amplified region (SCAR) marker, SCA168₁₄₅₃. The SCAR marker was tested using an F₂ population derived from the cross of T10-3-2 and HT10-3-2 and the results showed that this marker was closely linked with the unknown factor influencing the growth habit in HT10-3-2.     

<Emphasis Type="Italic">Ty</Emphasis>1<Emphasis Type="Italic">/copia</Emphasis>- and <Emphasis Type="Italic">Ty</Emphasis>3<Emphasis Type="Italic">/gypsy</Emphasis>-like DNA sequences in <Emphasis Type="Italic">Helianthus </Emphasis>species

Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.     

24-Epibrassinolide reduces stress in nematode-infected tomato (<Emphasis Type="Italic">Solanum lycopersicum</Emphasis> L.) plants cultured <Emphasis Type="Italic">in vitro</Emphasis>

24-Epibrassinolide (EBL) is considered the most probable brassinosteroid (BR) candidate that could be used for practical application in agriculture. EBL-induced stress-protective properties were evaluated in in vitro-grown tomato (Solanum lycopersicum L.) varieties Pusa Ruby (susceptible to nematodes) and PNR-7 (resistant to nematodes) during nematode pathogenesis. Sterilized tomato seeds treated with 10^?11, 10^?9, or 10^?7 M EBL and germinated in vitro were inoculated with second-stage juveniles of Meloidogyne incognita [(Kofoid and White) Chitwood]. Whole plant analyses of morphological and biochemical parameters 7 d after inoculation showed significant improvements in plant growth and development for both varieties and a highly significant reduction in the number of galls in the susceptible variety. Increased specific activities of antioxidative enzymes (catalase, ascorbate peroxidase, glutathione reductase, glutathione peroxidase, guaiacol peroxidase, and superoxide dismutase) were observed in EBL-treated seedlings of both varieties, but increases were higher in the resistant variety. A highly significant increase in antioxidants (ascorbic acid content, total flavonoid content, total glutathione content, and total phenolic content) was observed in EBL-treated Pusa Ruby seedlings, whereas in PNR-7, significant increases were found except for total flavonoid content, which increased non-significantly. Confocal microscopic images showed amelioration of stress in roots of EBL-treated seedlings as indicated by the decrease in level of green fluorescence in them as compared to untreated and nematode-inoculated roots.     

<Emphasis Type="Italic">Dunaliella salina</Emphasis> exopolysaccharides: a promising biostimulant for salt stress tolerance in tomato (<Emphasis Type="Italic">Solanum lycopersicum</Emphasis>)

Microalgal exopolysaccharides represent a potential sustainable alternative for the enhancement and protection of agricultural crops including management of both biotic and abiotic stress. In the present study, we investigated the potential of Dunaliella salina exopolysaccharides (PS) to attenuate the effect of salt stress on growth of Solanum lycopersicum, which was grown under different salinity levels (3 and 6 g L^?1 NaCl). The effects of PS treatment on plant growth, osmoprotectant molecules, protein content, and antioxidant enzymes activities of tomato plants under salt stress were analyzed. A metabolomics study showed that the exopolysaccharides released by D. salina contained sulfated moiety along with carbohydrates and uronic acids. The application of sulfated exopolysaccharides on tomato plants alleviated the salt stress and mitigated the decrease in length and dry weight of the plant’s shoot and root systems, as well as that of potassium (K⁺), and K⁺/Na⁺ ratio. Furthermore, the increase in proline, phenolic compounds, Na⁺, and antioxidant enzymes (CAT, POD, SOD) activities caused by salt stress were attenuated after the exopolysaccharide treatment. GC-MS metabolomics analysis showed that PS treatment allowed the activation and/or inhibition of various metabolic pathways involved in the plant’s tolerance to stress such as jasmonic acid-dependent pathways. This study shows the potential of microalgal exopolysaccharides for enhancing tomato tolerance to salt stress and highlights the possibility of their use as plant growth biostimulants under harsh environmental conditions.     

Reactive oxygen species (ROS) and antioxidative enzyme status in <Emphasis Type="Italic">Solanum lycopersicum</Emphasis> on priming with fluorescent <Emphasis Type="Italic">Pseudomonas</Emphasis> spp. against <Emphasis Type="Italic">Fusarium oxysporum</Emphasis>

In plants, ROS signaling and increase in activities of antioxidants are among defense responses. The present study describes the oxidative stress profiling in model host plant tomato (Solanum lycopersicum L.), during an invasion of the wilt pathogen Fusarium oxysporum f. sp. lycopersici with or without seed priming with Pseudomonas isolates M80, M96 and T109. Tomato seeds were primed with known Pseudomonas isolates M80, M96 and T109 and the forty-day- old plants were challenged with spores of F. oxysporum under greenhouse conditions. Leaf samples were collected at 0, 24, 48 72 and 96 h post fungal challenge and analysed for systemic level of oxidative stress parameters including total phenolics, proline, hydrogen peroxide, lipid peroxidation and enzymatic antioxidants. Disease incidence in the plants under greenhouse conditions was also calculated. Results revealed that priming with Pseudomonas isolates resulted in reduced oxidative stress in the host, during pathogen invasion. M80-priming showed highest antioxidative protection to the host plants during F. oxysporum invasion. The observed reduction in hydrogen peroxide and lipid peroxidation in primed plants was in agreement with the increased activities of the corresponding antioxidant enzymes. Greenhouse results showed that the highest wilt disease symptoms were with M80-priming followed by M96 and T109. The present study gives substantial evidences on the oxidative stress mitigation in response to Pseudomonas-priming on the model tomato-Fusarium interaction system.     

Revision of the <Emphasis Type="Italic">Serrulati</Emphasis> species of <Emphasis Type="Italic">Penstemon</Emphasis> section <Emphasis Type="Italic">Saccanthera</Emphasis> subsection <Emphasis Type="Italic">Serrulati</Emphasis>

A revision of Penstemon sect. Saccanthera subsect. Serrulati includes a new species (P. salmonensis), a new variety (P. triphyllus var. infernalis), and the elevation of a subspecies to species (P. curtiflorus), bringing the total number of species to eight, which are keyed and described, complete with nomenclature and type citations.     

<Emphasis Type="Italic">Agrobacterium</Emphasis><Emphasis Type="Italic">tumefaciens</Emphasis>-mediated transformation of callus cells of <Emphasis Type="Italic">Crataegus</Emphasis><Emphasis Type="Italic">aronia</Emphasis>

A genetic transformation system has been developed for callus cells of Crataegus aronia using Agrobacterium tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with 5 mg l⁻¹ Indole-3-butyric acid (IBA) and 0.5 mg l⁻¹ 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red colored callus was obtained on MS medium supplemented with 2 mg l⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l⁻¹ kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l⁻¹ hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this is the first time to report an Agrobacterium-mediated transformation system in Crataegus aronia.     

Electrofusion of protoplasts from <Emphasis Type="Italic">Solanum tuberosum</Emphasis>, <Emphasis Type="Italic">S. bulbocastanum</Emphasis> and <Emphasis Type="Italic">S. pinnatisectum</Emphasis>

This paper discusses a number of experiments performed, involving the fusion by an electric field of mesophyll protoplasts from Solanum tuberosum cv. Bintje, S. tuberosum dihaploid clones 243, 299 and the wild tuberous disease-resistant species S. bulbocastanum and S. pinnatisectum. Three fusion experiments (S. bulbocastanum + S. tuberosum dihaploid 243, S. pinnatisectum + S. tuberosum cv. Bintje and S. pinnatisectum + S. tuberosum dihaploid 299) yielded 542 calli, the 52 ones of which produced shoots. Obtained regenerants were estimated by the flow-cytometry (FC) and RAPD analysis to determine hybrid plants.The utilisation of the FC as a useful method for detecting somatic hybrids is also discussed in this paper. The combination S. bulbocastanum + S. tuberosum dihaploid 243 led to the creation of eight somatic hybrids, the combination S. pinnatisectum + S. tuberosum cv. Bintje yielded four somatic hybrids and the combination S. pinnatisectum + S. tuberosum dihaploid 299 resulted in no hybrid regenerants. Morphology in vitro, growth vigour and production of tuber-like structures were evaluated in hybrid plants. Plants were transferred in vivo for further estimation (acclimatization, habitus evaluation and tuberization ability).     

Prevalence of <Emphasis Type="Italic">Wolbachia</Emphasis> Infection in <Emphasis Type="Italic">Bemisia tabaci</Emphasis>

Wolbachia are obligate intracellular bacteria present in reproductive tissues of many arthropod species. It has been reported that few silverleafing populations of Bemisia tabaci were positive for Wolbachia, whereas non-silverleafing populations were more likely infected with Wolbachia and all that infect B. tabaci are Wolbachia belonging to supergroup B. However, current detection methods were shown to be not sensitive enough to uncover all infections. Herein, a protocol based on polymerase chain reaction–restriction fragment length polymorphism analysis of Wolbachia 16S ribosomal DNA is presented. A systematic survey for the prevalence of Wolbachia infection in natural populations of B. tabaci using this method revealed that (1) all populations of B. tabaci tested positive for Wolbachia and the overall infection rate reached 80.5% (293 positives in 364 tests); (2) both single infection and superinfection existed within individual whiteflies tested; and (3) silverleafing populations of B. tabaci most likely harbored A Wolbachia as single infection, whereas non-silverleafing populations tend to carry B Wolbachia as superinfection. It is clear that the Wolbachia infection pattern is closely related to the genetic races of B. tabaci, and the infection frequencies are apparently much higher than those described previously. This study shows that detection methods can significantly influence estimation of Wolbachia infection. It is supposed that Wolbachia may be acting as a biotic agent promoting rapid differentiation and speciation of B. tabaci. This is the most systematic survey of Wolbachia infection within B. tabaci.     

Fine mapping of the nematode resistance gene <Emphasis Type="Italic">Mi-3</Emphasis> in <Emphasis Type="Italic">Solanum peruvianum</Emphasis> and construction of a <Emphasis Type="Italic">S. lycopersicum</Emphasis> DNA contig spanning the locus

Currently, the only genetic resistance against root-knot nematodes in the cultivated tomato Solanum lycopersicum (Lycopersicon esculentum) is due to the gene Mi-1. Another resistance gene, Mi-3, identified in the related wild species Solanum peruvianum (Lycopersicon peruvianum) confers resistance to nematodes that are virulent on tomato lines that carry Mi-1, and is effective at temperatures at which Mi-1 is not effective (above 30°C). Two S. peruvianum populations segregating for Mi-3 were used to develop a high-resolution map of the Mi-3 region of chromosome 12. S. lycopersicum BACs carrying flanking markers were identified and used to construct a contig spanning the Mi-3 region. Markers generated from BAC-end sequences were mapped in S. peruvianum plants in which recombination events had occurred near Mi-3. Comparison of the S. peruvianum genetic map with the physical map of S. lycopersicum indicated that marker order is conserved between S. lycopersicum and S. peruvianum. The 600 kb contig between Mi-3-flanking markers TG180 and NR18 corresponds to a genetic distance of about 7.2 cM in S. peruvianum. We have identified a marker that completely cosegregates with Mi-3, as well as flanking markers within 0.25 cM of the gene. These markers can be used to introduce Mi-3 into cultivated tomato, either by conventional breeding or cloning strategies.     

Identification of novel small RNAs in tomato (<Emphasis Type="Italic">Solanum lycopersicum</Emphasis>)

To date, the majority of plant small RNAs (sRNA) have been identified in rice, poplar and Arabidopsis. To identify novel tomato sRNAs potentially involved in tomato specific processes such as fruit development and/or ripening, we cloned 4,018 sRNAs from tomato fruit tissue at the mature green stage. From this pool of sRNAs, we detected tomato homologues of nine known miRNAs, including miR482; a poplar miRNA not conserved in Arabidopsis or rice. We identified three novel putative miRNAs with flanking sequence that could be folded into a stem-loop precursor structure and which accumulated as 19-24nt RNA. One of these putative miRNAs (Put-miRNA3) exhibited significantly higher expression in fruit compared with leaf tissues, indicating a specific role in fruit development processes. We also identified nine sRNAs that accumulated as 19–24nt RNA species in tomato but genome sequence was not available for these loci. None of the nine sRNAs or three putative miRNAs possessed a homologue in Arabidopsis that had a precursor with a predicted stem-loop structure or that accumulated as a sRNA species, suggesting that the 12 sRNAs we have identified in tomato may have a species specific role in this model fruit species. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.