The Tripartite Lichen : Involvement of Cyanobacteria and Bacteria in Its Morphogenesis.

is an epiphytic lichen-forming fungus mainly distributed in Western Europe and Macaronesia in well-structured forests with ecological continuity that lack eutrophication. It is considered to be threatened or extinct in many territories in Europe (IUCN). Despite its biological and ecological relevance, studies on this taxon are scarce.

Gibberellic acid in Citrus spp. flowering and fruiting: A systematic review.

Background: In Citrus spp., gibberellic acid (GA) has been proposed to improve different processes related to crop cycle and yield. Accordingly, many studies have been published about how GA affects flowering and fruiting.

Inhibition of NO Biosynthetic Activities during Rehydration of Lichen Thalli Provokes Increases in Lipid Peroxidation.

Lichens are poikilohydrous symbiotic associations between a fungus, photosynthetic partners, and bacteria. They are tolerant to repeated desiccation/rehydration cycles and adapted to anhydrobiosis. Nitric oxide (NO) is a keystone for stress tolerance of lichens; during lichen rehydration, NO limits free radicals and lipid peroxidation but no data on the mechanisms of its synthesis exist.

Forced Flowering in Mandarin Trees under Phytotron Conditions.

Phytotron has been widely used to assess the effect of numerous parameters on the development of many species. However, less information is available on how to achieve fast profuse flowering in young fruit trees with this plant growth chamber. This study aimed to outline the design and performance of a fast clear methodology to force flowering in young mandarin trees (cv.

Characterization of the responses to saline stress in the symbiotic green microalga Trebouxia sp. TR9.

For the first time we provide a study on the physiological, ultrastructural and molecular effects of salt stress on a terrestrial symbiotic green microalga, Trebouxia sp. TR9. Although tolerance to saline conditions has been thoroughly studied in plants and, to an extent, free-living microalgae, scientific data regarding salt stress on symbiotic lichen microalgae is scarce to non-existent.

Molecular and morphological diversity of Trebouxia microalgae in sphaerothallioid Circinaria spp. lichens.

Three vagrant (Circinaria hispida, Circinaria gyrosa, and Circinaria sp. 'paramerae') and one crustose (semi-vagrant, Circinaria sp. 'oromediterranea') lichens growing in very continental areas in the Iberian Peninsula were selected to study the phycobiont diversity.

De novo assembly of Phlomis purpurea after challenging with Phytophthora cinnamomi.

Background: Phlomis plants are a source of biological active substances with potential applications in the control of phytopathogens. Phlomis purpurea (Lamiaceae) is autochthonous of southern Iberian Peninsula and Morocco and was found to be resistant to Phytophthora cinnamomi. Phlomis purpurea has revealed antagonistic effect in the rhizosphere of Quercus suber and Q.

Coordinated ultrastructural and phylogenomic analyses shed light on the hidden phycobiont diversity of Trebouxia microalgae in Ramalina fraxinea.

The precise boundary delineations between taxa in symbiotic associations are very important for evolutionary and ecophysiological studies. Growing evidence indicates that in many cases, the use of either morphological characters or molecular markers results in diversity underestimation. In lichen symbioses, Trebouxia is the most common genus of lichen phycobionts, however, the diversity within this genus has been poorly studied and as such there is no clear species concept.

Molecular phylogeny and ultrastructure of the lichen microalga Asterochloris mediterranea sp. nov. from Mediterranean and Canary Islands ecosystems.

The microalgae of the genus Asterochloris are the preferential phycobionts in Cladonia, Lepraria and Stereocaulon lichens. Recent studies have highlighted the hidden diversity of the genus, even though phycobionts hosting species of the genus Cladonia in Mediterranean and Canarian ecosystems have been poorly explored. Phylogenetic analyses were made by concatenation of the sequences obtained with a plastid - LSU rDNA - and two nuclear - internal transcribed spacer (ITS) rDNA and actin - molecular markers of the phycobionts living in several populations of the Cladonia convoluta-Cladonia foliacea complex, Cladonia rangiformis and Cladonia cervicornis s.

Ultrastructural and histochemical analysis reveals ethylene-induced responses underlying reduced peel collapse in detached citrus fruit.

Fruits from many citrus cultivars develop depressed areas in the flavedo (outer part of the peel) and albedo (inner part) following detachment. Although ultrastructural analysis may provide important information about multiple plant responses to stresses and external stimuli at the cell and tissue levels, and despite the proved efficacy of ethylene in reducing peel damage in citrus fruit, cytological responses of this horticultural crop to protective ethylene concentrations have not yet been reported. We show that applying high ethylene levels (2 μL L(-1) for 14 days) causes sublethal stress as it favored the alteration of cuticle, vacuole, middle lamella and primary wall, especially in the albedo cells, but reduced peel collapse in detached mature "Navelate" oranges (C.

Physiological, anatomical and biomass partitioning responses to ozone in the Mediterranean endemic plant Lamottea dianae.

Ozone effects on the perennial forb Lamottea dianae were studied in an open-top chamber experiment. Ozone was found to induce reductions in CO₂ assimilation and water use efficiency in the leaves of this species. These reductions were mainly related to a decline in the in vivo CO₂ fixation capacity of Rubisco (V(c,max)), rather than to stomatal limitations or photoinhibitory damage (F(v):F(m)).

Two Trebouxia algae with different physiological performances are ever-present in lichen thalli of Ramalina farinacea. Coexistence versus competition?

Ramalina farinacea is an epiphytic fruticose lichen that is relatively abundant in areas with Mediterranean, subtropical or temperate climates. Little is known about photobiont diversity in different lichen populations. The present study examines the phycobiont composition of several geographically distant populations of R.

Ozone-induced reductions in below-ground biomass: an anatomical approach in potato.

Potato plants were grown in open-top chambers under three ozone concentrations during two complete cropping seasons (93 and 77 d in 2004 and 2005, respectively). The effects of chronic exposure to ozone on leaf anatomy, cell ultrastructure and crop yield were studied. Severe cell damage was found, even at ambient ozone levels, mainly affecting the spongy parenchyma and areas near the stomata.