A dual-omics approach for profiling plant responses to biostimulant applications under controlled and field conditions

A comprehensive approach using phenomics and global transcriptomics for dissecting plant response to biostimulants is illustrated with tomato (Solanum lycopersicum cv. Micro-Tom and Rio Grande) plants cultivated in the laboratory, greenhouse, and open field conditions. Biostimulant treatment based on an Ascophyllum nodosum extract (ANE) was applied as a foliar spray with two doses (1 or 2 l ha-1) at three different phenological stages (BBCH51, BBCH61, and BBCH65) during the flowering phase. Both ANE doses resulted in greater net photosynthesis rate, stomatal conductance, and fruit yield across all culture conditions. A global transcriptomic analysis of leaves from plants grown in the climate chamber, revealed a greater number of differentially expressed genes (DEGs) with the low ANE dose compared to the greater one. The second and third applications induced broader transcriptome changes compared to the first one, indicating a cumulative treatment effect. The functional enrichment analysis of DEGs highlighted pathways related to stimulus-response and photosynthesis, consistent with the morpho-physiological observations. This study is the first comprehensive dual-omics approach for profiling plant responses to biostimulants across three different culture conditions

Transcriptomic and physiological approaches to decipher cold stress mitigation exerted by brown-seaweed extract application in tomato

Chilling temperatures represent a challenge for crop species originating from warm geographical areas. In this situation, biostimulants serve as an eco-friendly resource to mitigate cold stress in crops. Tomato (Solanum lycopersicum L.) is an economically important vegetable crop, but quite sensitive to cold stress, which it encounters in both open field and greenhouse settings. In this study, the biostimulant effect of a brown-seaweed extract (BSE) has been evaluated in tomato exposed to low temperature. To assess the product effects, physiological and molecular characterizations were conducted. Under cold stress conditions, stomatal conductance, net photosynthesis, and yield were significantly (p ≤ 0.05) higher in BSE-treated plants compared to the untreated ones. A global transcriptomic survey after BSE application revealed the impact of the BSE treatment on genes leading to key responses to cold stress. This was highlighted by the significantly enriched GO categories relative to proline (GO:0006560), flavonoids (GO:0009812, GO:0009813), and chlorophyll (GO:0015994). Molecular data were integrated by biochemical analysis showing that the BSE treatment causes greater proline, polyphenols, flavonoids, tannins, and carotenoids contents.The study highlighted the role of antioxidant molecules to enhance tomato tolerance to low temperature mediated by BSE-based biostimulant

High-resolution radiation hybrid mapping in wheat: an essential tool for the construction of the wheat physical maps

ArtigoO poema épico da época moderna nasce na literatura portuguesa como oceânico logo a partir da sua gestação. Este estudo enquadra a sua génese num contexto europeu.Università di Roma, La Sapienz

Single Nucleotide Polymorphism Genotyping for Breeding and Genetics Applications in Chickpea and Pigeonpea using the BeadXpress Platform

Single nucleotide polymorphisms (SNPs) are ideal molecular markers due to their higher abundance. Although several types of genotyping platforms for assaying large number of SNPs are available, in cases such as marker-assisted selection, where few markers are required for genotyping a set of potential lines, high-throughput SNP genotyping platforms (e.g., iScan or Infinium) may not be cost effective. In this scenario, GoldenGate assays based on VeraCode technology using Illumina BeadXpress seems to be the most cost-effective platform. The objective of this study was to develop cost-effective SNP genotyping platforms in chickpea (Cicer arietinum L.) and pigeonpea (Cajanus cajan L.). Two sets of SNPs, one each for chickpea (96 SNPs) and pigeonpea (48 SNPs), were developed and tested by genotyping 288 diverse genotypes from respective reference sets. The SNPs selected for the oligo pool assays had high transferability to crop wild relative species. The mean polymorphism information content value of assayed SNP markers was 0.31 and 0.32 in chickpea and pigeonpea, respectively. No unique pattern was observed in the chickpea reference set whereas two major groups were observed in the case of the pigeonpea reference set. The Illumina BeadXpress platform assays developed for chickpea and pigeonpea are highly informative and cost effective for undertaking genetic studies in these legume species

In vitro induction and proliferation of protocorm-like bodies (PLBs) from leaf segments of Phalaenopsis bellina (Rchb.f.) Christenson

An in vitro culture procedure was established to induce protocorm-like bodies (PLBs) from leaf segments of the Phalaenopsis bellina (Rchb.f.) Christenson directly from epidermal cells without intervening callus on ½ strength modified Murashige and Skoog (MS) (in Physiol Plant 15:473–497, 1962) medium supplemented with 1-Naphthaleneacetic acid (NAA; 0, 0.1, 1 mg/l) and Thidiazuron (TDZ; 0, 0.1, 1, 3 mg/l). The best response was established at 3 mg/l TDZ which induced 78% of leaf segments to form a mean number of 14 PLBs per explant after 16 weeks of culture. No PLBs were found when leaf segments were cultured on ½ strength modified MS media supplemented with 0.1 and 1 mg/l NAA. The best induction percentage for auxin: cytokinin combination was at the combination of NAA and TDZ at 1.0 and 3.0 mg/l which gave 72% induction with 9 PLBs per explant. Semi-solid ½ strength MS and liquid Vacin and Went (VW) (in Bot Gaz 110:605–613, 1949) medium were used in order to find the highest survival and number of PLBs proliferation after 3 months in culture. Half strength MS showed an average of 9 PLBs in comparison with VW with an average of 5.3 PLBs per explants. Histological observations revealed that the regenerated PLBs were generally formed from the epidermal layers of the posterior regions of the leaf segments. Scanning electron micrograph of PLBs showed the origin of newly formed PLB from the peripheral region of leaf segments

Macro-Climatic Distribution Limits Show Both Niche Expansion and Niche Specialization among C4 Panicoids

Grasses are ancestrally tropical understory species whose current dominance in warm open habitats is linked to the evolution of C4 photosynthesis. C4 grasses maintain high rates of photosynthesis in warm and water stressed environments, and the syndrome is considered to induce niche shifts into these habitats while adaptation to cold ones may be compromised. Global biogeographic analyses of C4 grasses have, however, concentrated on diversity patterns, while paying little attention to distributional limits. Using phylogenetic contrast analyses, we compared macro-climatic distribution limits among ~1300 grasses from the subfamily Panicoideae, which includes 4/5 of the known photosynthetic transitions in grasses. We explored whether evolution of C4 photosynthesis correlates with niche expansions, niche changes, or stasis at subfamily level and within the two tribes Paniceae and Paspaleae. We compared the climatic extremes of growing season temperatures, aridity, and mean temperatures of the coldest months. We found support for all the known biogeographic distribution patterns of C4 species, these patterns were, however, formed both by niche expansion and niche changes. The only ubiquitous response to a change in the photosynthetic pathway within Panicoideae was a niche expansion of the C4 species into regions with higher growing season temperatures, but without a withdrawal from the inherited climate niche. Other patterns varied among the tribes, as macro-climatic niche evolution in the American tribe Paspaleae differed from the pattern supported in the globally distributed tribe Paniceae and at family level.Fil: Aagesen, Lone. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Biganzoli, Fernando. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bena, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Godoy Bürki, Ana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Reinheimer, Renata. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Zuloaga, Fernando Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentin

Development of a Set of Chromosome Segment Substitution Lines in Pearl Millet [Pennisetum glaucum (L.) R. Br.]

The detection of minor quantitative trait loci (QTL) with conventional mapping populations can be complicated by the overshadowing effect of major QTL as well as by interactions between QTL. To overcome these constraints, we developed a set of chromosome segment substitution lines (CSSLs) by introgression of overlapping chromosome segments from 863B into ICMB 841 background for use in QTL detection, fine mapping, and trait mechanism studies, especially for complex traits. Since each CSSL carries one or a few donor segments in the genetic background of the recurrent genotype, the QTL interaction is confined to genes present on small homozygous substituted segments. Advanced generation backcross progenies (1492), expected to provide coverage across the mapped length of each of the seven pearl millet linkage groups (LGs), were genotyped at 74 marker loci [(48 simple sequence repeats (SSRs), 21 single strand conformation polymorphism-single nucleotide polymorphism (SSCP-SNP), and 5 sequence tagged sites (STSs)] identifying 124 segment introgression homozygotes (13 for LG1, 9 for LG2, 10 for LG3, 41 for LG4, 23 for LG5, 11 for LG6, and 17 for LG7). These CSSLs consisted of 1–3 homozygous introgression segments substituted from 863B in the genetic background of the recurrent parent ICMB 841 and among them, 54 represent unique lines with the donor chromosome segment averaging 100.69 cM. These CSSLs developed here provide a nearly ideal set of genetic stocks for mapping and fine mapping the multitude of traits for which their parents differ

A neural oscillations perspective on phonological development and phonological processing in developmental dyslexia

Children’s ability to reflect upon and manipulate the sounds in words (’phonological awareness’) develops as part of natural language acquisition, supports reading acquisition, and develops further as reading and spelling are learned. Children with developmental dyslexia typically have impairments in phonological awareness. Many developmental factors contribute to individual differences in phonological development. One important source of individual differences may be the child’s sensory/neural processing of the speech signal from an amplitude modulation (~ energy or intensity variation) perspective, which may affect the quality of the sensory/neural representations (’phonological representations’) that support phonological awareness. During speech encoding, brain electrical rhythms (oscillations, rhythmic variations in neural excitability) re-calibrate their temporal activity to be in time with rhythmic energy variations in the speech signal. The accuracy of this neural alignment or ’entrainment’ process is related to speech intelligibility. Recent neural studies demonstrate atypical oscillatory function at slower rates in children with developmental dyslexia. Potential relations with the development of phonological awareness by children with dyslexia are discussed.Medical Research Council, G0400574 and G090237