6 research outputs found
Ovule transcriptome analysis discloses deregulation of genes and pathways in sexual and apomictic Limonium species (Plumbaginaceae)
The genus Limonium Mill. (sea lavenders) includes species with sexual and apomixis
reproductive strategies, although the genes involved in these processes are unknown. To explore the
mechanisms beyond these reproduction modes, transcriptome profiling of sexual, male sterile, and
facultative apomictic species was carried out using ovules from different developmental stages. In
total, 15,166 unigenes were found to be differentially expressed with apomictic vs. sexual reproduc-
tion, of which 4275 were uniquely annotated using an Arabidopsis thaliana database, with different
regulations according to each stage and/or species compared. Gene ontology (GO) enrichment analy-
sis indicated that genes related to tubulin, actin, the ubiquitin degradation process, reactive oxygen
species scavenging, hormone signaling such as the ethylene signaling pathway and gibberellic acid-
dependent signal, and transcription factors were found among differentially expressed genes (DEGs)
between apomictic and sexual plants. We found that 24% of uniquely annotated DEGs were likely to
be implicated in flower development, male sterility, pollen formation, pollen-stigma interactions, and
pollen tube formation. The present study identifies candidate genes that are highly associated with
distinct reproductive modes and sheds light on the molecular mechanisms of apomixis expression in
Limonium spinfo:eu-repo/semantics/publishedVersio
Unravelling the combined use of soil and microbial technologies to optimize cultivation of Halophyte Limonium algarvense (Plumbaginaceae) using saline soils and water
Salt-affected soils have detrimental effects on agriculture and ecosystems. However,
these soils can still be used for halophyte (salt-tolerant plants) cultivation using brackish and/or
saline water. In this study, we employed soil technologies and mutualistic microorganisms as a
sustainable strategy to improve the growth and reproduction of the halophyte Limonium algarvense
Erben’s growth and reproduction under saline conditions. A microcosm assay was conducted under
controlled greenhouse conditions to cultivate L. algarvense using a saline Fluvisol (FLU) amended—or
not—with a Technosol (TEC). Plants were inoculated with the arbuscular mycorrhizal fungus (AMF)
Rhizoglomus irregulare and/or a consortium of plant growth-promoting bacteria (PGPB), and they
were irrigated with estuarine water. Soil enzyme analysis and physicochemical characterisation of
the soils, collected at the beginning and at the end of the assay, were carried out. The physiological
status of non-inoculated and inoculated plants was monitored during the assay for 4 months, and
AMF root colonisation was evaluated. In FLU, only plants inoculated with the AMF survived. These
plants had lower number of leaves, and shoot and root dry biomass than the ones grown in the TEC
by the end of the assay. In the TEC, PGPB inoculation led to higher NDVI and PRI values, and AMF
inoculation promoted higher reproductive development but not pollen fertility. The findings show
that the combined use of soil and microbial technologies can be successfully applied to cultivate
L. algarvense, suggesting their generalized use for other Limonium species with economic interest,
while contributing to the sustainable use of marginal lands.Federation of European Microbiological Societies (FEMS) (FEMSGO-
2020-203), University of Sevilla (Spain; Plan Propio de Investigación y Tranferencia 2021 Ayuda
A1-I.3A1) for grants to support the stays at ISA-ULisboa (Portugal).info:eu-repo/semantics/publishedVersio
Habitat specificity of a threatened and endemic cliff-dwelling halophyte
Research ArticleCoastal areas and other saline environments are major contributors to regional and global biodiversity
patterns. In these environments, rapidly changing gradients require highly specialized plants like halophytes.
In European coastal cliff-tops, rocky and sandy seashores, and saltmarshes, typical halophytes from the genus
Limonium are commonly found. Among them, the aneuploid tetraploid (2n ¼ 4x ¼ 35, 36, 37) Limonium multiflorum,
endemic to the west coast of Portugal, is an interesting case study for investigating the ecology and conservation
of a halophyte agamospermic species. Although it is listed in the IUCN red list of threatened species,
information on its population size or rarity, as well as its ecology, in some respects is still unknown. Field surveys
in the largest known population were performed (Raso cape, Portugal) in order to determine habitat requirements
and conservation status. A total of 88 quadrats were monitored, 43 of which contained at least one L. multiflorum
individual. For each sampled quadrat, four abiotic and four biotic variables as well as two spatially derived variables
were recorded. Principal component analysis and cluster analysis showed narrow habitat specificity for this species
which appeared to be intolerant to competition with invasive alien plants. We conclude that in situ conservation
in a local ‘hotspot’ of this rare and vulnerable species emerges as a priority in order to ensure that biodiversity is not los
Phylogeography and modes of reproduction in diploid and tetraploid halophytes of Limonium species (Plumbaginaceae): evidence for a pattern of geographical parthenogenesis
Background and Aims The genus Limonium (Plumbaginaceae) has long been recognized to have sexual and
apomictic (asexual seed formation) modes of reproduction. This study aimed to elucidate phylogeographical patterns
and modes of reproduction in diploid and tetraploid Limonium species, namely three putative sexual diploid
species with morphological affinities (L. nydeggeri, L. ovalifolium, L. lanceolatum) and three related, probably apomict
tetraploid species (L. binervosum, L. dodartii, L. multiflorum).
Methods cpDNA diversity and differentiation between natural populations of the species were investigated using
two chloroplast sequence regions (trnL intron and trnL–trnF intergenic spacer). Floral heteromorphies, ovule
cytoembryological analyses and pollination and crossing tests were performed in representative species of each
ploidy group, namely diploid L. ovalifolium and tetraploid L. multiflorum, using plants from greenhouse collections.
Key Results and Conclusions Genetic analyses showed that diploid species have a higher haplotype diversity
and a higher number of unique (endemic) haplotypes than tetraploid species. Network analysis revealed correlations
between cpDNA haplotype distribution and ploidy groups, species groups and geographical origin, and haplotype
sharing within and among species with distinct ploidy levels. Reproductive biology analyses showed that diploid
L. ovalifolium mainly forms meiotically reduced tetrasporic embryo sacs of Gagea ova, Adoxa and Drusa types.
Limonium multiflorum, however, has only unreduced, diplosporic (apomictic) embryo sacs of Rudbeckia type, and
autonomous apomictic development seems to occur. Taken together, the findings provide evidence of a pattern of
‘geographical parthenogenesis’ in which quaternary climatic oscillations appear to be involved in the geographical
patterns of coastal diploid and tetraploid Limonium speciesinfo:eu-repo/semantics/publishedVersio
Secretory structures in plants: lessons from the Plumbaginaceae on their origin, evolution and roles in stress tolerance
Special IssueThe Plumbaginaceae (non-core Caryophyllales) is a family well known for species
adapted to a wide range of arid and saline habitats. Of its salt-tolerant species, at
least 45 are in the genus Limonium; two in each of Aegialitis, Limoniastrum and
Myriolimon, and one each in Psylliostachys, Armeria, Ceratostigma, Goniolimon and
Plumbago. All the halophytic members of the family have salt glands, which are also
common in the closely related Tamaricaceae and Frankeniaceae. The halophytic species
of the three families can secrete a range of ions (Na+, K+, Ca2+, Mg2+, Cl−,
HCO3
−, SO4
2-) and other elements (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn). Salt glands
are, however, absent in salt-tolerant members of the sister family Polygonaceae. We
describe the structure of the salt glands in the three families and consider whether
glands might have arisen as a means to avoid the toxicity of Na+ and/or Cl− or to regulate
Ca2+ concentrations within the leaves. We conclude that the establishment of
lineages with salt glands took place after the split between the Polygonaceae and its
sister group the Plumbaginaceaeinfo:eu-repo/semantics/publishedVersio
Limonium mucronatum: plant communities and cytogenetic characterization of an endemic of the Moroccan Atlantic Coast
Limonium mucronatum (L.f.) Chaz. (Plumbaginaceae), a strict endemic of Morocco, has a restricted
range in the littoral zone between Rabat and Tan Tan (Draa valley). This coastal region at the junction
of Mediterranean, Canary and Saharan influences is of considerable biogeographical interest. However,
little information exists on L. mucronatum communities and its relationship with bioclimatology or
chromosome polymorphisms, which may have an impact in the context of plant conservation. In this
study, we analysed L. mucronatum communities and performed a cytometric and karyological characterization
of this rare species. Results showed two plant communities associated with this species
related to a latitudinal and bioclimatic gradient along the surveyed region. Our study provided for the
first time new data regarding nuclear DNA amount and about the numbers, positions and organization
of 45S rDNA loci in L. mucronatum. Remarkably, cytogenetic analyses revealed homogeneous ploidy
across all studied populations with all individuals with 2n¼12 chromosomes. The results obtained are
discussed in the context of the originality of flora and the threats to L. mucronatum communities, and
in the perspective of a conservation strategy for this endemic speciesinfo:eu-repo/semantics/publishedVersio