Seed Priming with Silicon as a Potential to Increase Salt Stress Tolerance in Lathyrus odoratus

Water shortage is a major problem limiting the expansion of green areas and landscapes. Using seawater as an alternative source of potable water is not a novel idea, but the issue of salt stress needs to be resolved. Salinity has a negative impact on growth and the aesthetic value of ornamental plants. In order to overcome these challenges, Lathyrus odoratus seeds were hydro-primed and halo-primed with silicon (Si) and silicon nanoparticles (SiNPs), and exposed to seawater levels. Seawater markedly reduced seed germination and growth of Lathyrus seedlings, but halo-priming was shown to significantly alleviate its negative effects. Broadly, SiNPs increased the germination percentage, reduced photosynthetic pigments and carbohydrates decrease, and enhanced water relations, despite having a negative effect on germination speed. Halo-priming significantly increased the proline content and the activities of certain enzymatic (SOD, APX and CAT) and nonenzymatic (phenolic and flavonoids) compounds, that positively influenced oxidative stress (lower MDA and H2O2 accumulation), resulting in seedlings with more salt stress tolerance. Halo-priming with Si or SiNPs enhanced the Si and K+ contents, and K+/Na+ ratio, associated with a reduction in Na+ accumulation. Generally, halo-priming with Si or SiNPs increased Lathyrus seedlings salt stress tolerance, which was confirmed using seawater treatments via improving germination percentage, seedlings growth and activation of the antioxidant machinery, which detoxifies reactive oxygen species (ROS).

Lathyrus odoratus (sweet pea).

Lathyrus odoratus is a fast-growing, annual herb native only to southwest Italy and Sicily, but widely introduced as an ornamental. The ability of this species to tolerate a wide range of habitats, including disturbed areas, roadsides, secondary forests, as well as natural forests, means that it has the potential to spread much further than it has to date. This species has a climbing or sprawling habit, and consequently, has the capability to displace native species. Currently it is considered invasive in New Zealand and 'possibly invasive' in the Dominican Republic. However, in its native range it is listed as Near Threatened, as it is subject to wild collection threat due to its commercial value.

Ribosomal DNA localization on Lathyrus species chromosomes by FISH

Background Fluorescence In Situ Hybridization (FISH) played an essential role to locate the ribosomal RNA genes on the chromosomes that offered a new tool to study the chromosome structure and evolution in plant. The 45S and 5S rRNA genes are independent and localized at one or more loci per the chromosome complement, their positions along chromosomes offer useful markers for chromosome discriminations. In the current study FISH has been performed to locate 45S and 5S rRNA genes on the chromosomes of nine Lathyrus species belong to five different sections, all have chromosome number 2n=14, Lathyrus gorgoni Parl, Lathyrus hirsutus L., Lathyrus amphicarpos L., Lathyrus odoratus L., Lathyrus sphaericus Retz, Lathyrus incospicuus L, Lathyrus paranensis Burkart, Lathyrus nissolia L., and Lathyrus articulates L. Results The revealed loci of 45S and 5S rDNA by FISH on metaphase chromosomes of the examined species were as follow: all of the studied species have one 45S rDNA locus and one 5S rDNA locus except L. odoratus L., L. amphicarpos L. and L. sphaericus Retz L. have two loci of 5S rDNA. Three out of the nine examined species have the loci of 45S and 5S rRNA genes on the opposite arms of the same chromosome (L. nissolia L., L. amphicarpos L., and L. incospicuus L.), while L. hirsutus L. has both loci on the same chromosome arm. The other five species showed the loci of the two types of rDNA on different chromosomes. Conclusion The detected 5S and 45S rDNA loci in Lathyrus could be used as chromosomal markers to discriminate the chromosome pairs of the examined species. FISH could discriminate only one chromosome pair out of the seven pairs in three species, in L. hirsutus L., L. nissolia L. and L. incospicuus L., and two chromosome pairs in five species, in L. paranensis Burkart, L. odoratus L., L. amphicarpos L., L. gorgoni Parl. and L. articulatus L., while it could discriminate three chromosome pairs in L. sphaericus Retz. these results could contribute into the physical genome mapping of Lathyrus species and the evolution of rDNA patterns by FISH in the coming studies in future.

Análisis taxonómico molecular de individuos del genero Lathyrus hallados en el extremo norte de Chile, mediante DNA barcoding

Introducción y objetivos: La presente investigación corresponde a un análisis taxonómico molecular de muestras florales obtenidas de plantas establecidas naturalmente en una zona recóndita del Desierto de Atacama, Región de Arica-Parinacota, Chile. En primera instancia, las muestras morfológicamente se atribuyeron al género Lathyrus, sin embargo, conforme a la literatura actual, no se han registrado individuos de este género en la región, dado esto, se ha generado confusión en la identificación de las muestras colectadas. Por lo cual, la presente investigación tiene por objetivo identificar genéticamente las especies presuntamente de Lathyrus, mediante DNA Barcoding. M&M: En el presente estudio se evaluaron estos individuos mediante un análisis filogenético para determinar su identidad taxonómica a partir de secuencias ITS (nuclear) y secuencias psbA, matK y rpoC1 (plastídicas). Resultados: Los resultados demostraron que los individuos están relacionados a la especie Lathyrus odoratus. Conclusiones: Los cuatro loci de DNA barcoding, permitieron identificar genéticamente las muestras como L. odoratus, el cual se encuentra creciendo de manera natural en Chile.

Functional Characterization of Terpene Synthases Accounting for the Volatilized-Terpene Heterogeneity in Lathyrus odoratus Cultivar Flowers

Lathyrus odoratus (sweet pea) is an ornamental plant with exceptional floral scent, previously used as an experimental organism in the early development of Mendelian genetics. However, its terpene synthases (TPSs), which act as metabolic gatekeepers in the biosynthesis of volatile terpenoids, remain to be characterized. Auto-Headspace Solid-phase Microextraction/Gas chromatography–mass spectrometry analysis of floral volatile terpene constituents from seven sweet pea cultivars identified α-bergamotene, linalool, (−)-α-cubebene, geraniol, β-caryophyllene and β-sesquiphellandrene as the dominant compounds. RNA sequencing was performed to profile the transcriptome of L. odoratus flowers. Bioinformatic analysis identified eight TPS genes (acronymed as LoTPS) that were successfully cloned, heterologously expressed and functionally analyzed. LoTPS4 and LoTPS7, belonging to the TPS-b clade, biochemically catalyzed the formation of monoterpenes and sesquiterpenes. LoTPS3 and LoTPS8, placed in the TPS-a clade, also generated monoterpenes and sesquiterpenes, while LoTPS12 belonging to the TPS-g clade showed linalool/nerolidol synthase activity. Notably, biochemical assays of the recombinant LoTPS proteins revealed their catalytic promiscuity, and the enzymatic products were basically consistent with major volatile compounds released from sweet pea flowers. The data from our study lay the foundation for the chemical ecology, molecular genetics and biotechnological improvement of sweet pea and other legumes (Fabaceae).

Pollen Grains Morphology of Angiosperms

Pollen morphology of fourteen species of angiosperms from Kathmandu valley was investigated using aceto-carmine and palynological characters such as pollen size, shape, aperture numbers and exine sculpture were evaluated. The results indicate that various types of pollen grains are in angiosperms. In this investigation Pollen grains of Linum usitatissimum L. from the family Linaceae, Lathyrus odoratus L. from Fabaceae, Magnolia grandiflora L. from Magnoliaceae, Malva alcea L. and Malva sida L. from Malvaceae, Murraya koenigii Spreng from Rutaceae, Nerium oleander L. from Apocynaceae studied. Likewise, Ocimum tenuiflorum L., Salvia coccinea Buchz ex Etl. Salvia splendens Sellow ex J.A. Schultes from Lamiaceae, Oenothera rosea L. from Onagraceae, Prunus persica (L.) Batsch. from Rosaceae, Solanum nigrum L. from Solanaceae and Zinnia elegans L. from Asteraceae were studied in this investigation. Shape of the pollen grains found to be spheroidal, sub-spheroidal, elongate, oval, circular, ellipsoidal and triangular type. Ornamentation of exine wall found to be echinate, smooth, coarse, wrinkle and tected type. Aperture of the pollen grains found to be triporate to periporate. Sizes of the pollen grains encountered in this study were large, medium and small. The high diversity of exine ornamentation type in pollen grains of angiosperms has been associated to diversity in pollination systems. Echinate pollen grains train the bees to restrict to nectar collection and help the flowers to save more pollen grains for pollination. Smooth walled pollen grains are linked with wind or water pollination. Int. J. Appl. Sci. Biotechnol. Vol 8(2): 205-210

PHARMACOLOGICAL STUDIES ON PLANTS BELONGING TO THE FAMILY LEGUMINOSAE

Objective: The study is an attempt to quantitatively measure the presence of Anti-Parkinsons drug Levodopa in members of the family Leguminosae. Methods: Reverse phase HPLC, Phytochemical analysis carried out using Bioinformatic tools (ChemMine and Cytoscape). The dried seed samples of Mucuna pruriens (Linn.), Cassia fistula (Linn.), Lathyrus odoratus (Linn.), Glycine max (L. Merr.), and Mimosa pudica (L) were selected for the study of Levodopa, and compared with Tecoma stans from the family Bignoniaceae., and antimicrobial activity was conducted on selected bacteria. Results: Mucuna pruriens showed the presence of Levodopa in quantifiable higher quantity i.e., 705.5985 ????g/20 ml, whereas other plant samples contained very less quantity. The antimicrobial activity of the selected plants on E. coli and Bacillus showed positive results. Conclusion: The study proves the presence of Anti-Parkinsons drug Levodopa in Mucuna pruriens, whereas absent in the other plants. The selected plants prove the anti-bacterial activity on the selected bacteria.