<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Almeida, Tânia</style></author><author><style face="normal" font="default" size="100%">Pinto, Glória</style></author><author><style face="normal" font="default" size="100%">Correia, Barbara</style></author><author><style face="normal" font="default" size="100%">Santos, Conceição</style></author><author><style face="normal" font="default" size="100%">Gonçalves, Sónia</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">QsMYB1 expression is modulated in response to heat and drought stresses and during plant recovery in Quercus suber</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Physiology and Biochemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Abiotic stress</style></keyword><keyword><style  face="normal" font="default" size="100%">Adaptation</style></keyword><keyword><style  face="normal" font="default" size="100%">Cork oak</style></keyword><keyword><style  face="normal" font="default" size="100%">Droughts</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene expression</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes</style></keyword><keyword><style  face="normal" font="default" size="100%">Hot Temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">Physiological</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Bark</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Proteins: genetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Proteins: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: genetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">R2R3-MYB</style></keyword><keyword><style  face="normal" font="default" size="100%">Recovery</style></keyword><keyword><style  face="normal" font="default" size="100%">RNA Splicing</style></keyword><keyword><style  face="normal" font="default" size="100%">Stress</style></keyword><keyword><style  face="normal" font="default" size="100%">Transcription Factors</style></keyword><keyword><style  face="normal" font="default" size="100%">Transcription Factors: genetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Transcription Factors: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">water</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2013///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/24161757http://www.sciencedirect.com/science/article/pii/S0981942813003537</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">73</style></volume><pages><style face="normal" font="default" size="100%">274 - 281</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Abstract Cork oak is an economically important forest species showing a great tolerance to high temperatures and shortage of water. However, the mechanisms underlying this plasticity are still poorly understood. Among the stress regulators, transcription factors (TFs) are especially important since they can control a wide range of stress-inducible genes, which make them powerful targets for genetic engineering of stress tolerance. Here we evaluated the influence of increasing temperatures (up to 55 °C) or drought (18% field capacity, FC) on the expression profile of an R2R3-MYB transcription factor of cork oak, the QsMYB1. QsMYB1 was previously identified as being preferentially expressed in cork tissues and as having an associated alternative splicing mechanism, which results in two different transcripts (QsMYB1.1 and QsMYB1.2). Expression analysis by reverse transcription quantitative PCR (RT-qPCR) revealed that increasing temperatures led to a gradual down-regulation of QsMYB1 transcripts with more effect on QsMYB1.1 abundance. On the other hand, under drought condition, expression of QsMYB1 variants, mainly the QsMYB1.2, was transiently up-regulated shortly after the stress imposition. Recovery from each stress has also resulted in a differential response by both QsMYB1 transcripts. Several physiological and biochemical parameters (plant water status, chlorophyll fluorescence, lipid peroxidation and proline content) were determined in order to monitor the plant performance under stress and recovery. In conclusion, this report provides the first evidence that QsMYB1 TF may have a putative function in the regulatory network of cork oak response to heat and drought stresses and during plant recovery.</style></abstract><notes><style face="normal" font="default" size="100%">From Duplicate 1 (QsMYB1 expression is modulated in response to heat and drought stresses and during plant recovery in Quercus suber - Almeida, Tânia; Pinto, Glória; Correia, Barbara; Santos, Conceição; Gonçalves, Sónia)From Duplicate 1 (QsMYB1 expression is modulated in response to heat and drought stresses and during plant recovery in Quercus suber - Almeida, Tânia; Pinto, Glória; Correia, Barbara; Santos, Conceição; Gonçalves, Sónia)The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Elsevier Masson SAS&lt;br/&gt;accession-num: 24161757</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Almeida, Tânia</style></author><author><style face="normal" font="default" size="100%">Menéndez, Esther</style></author><author><style face="normal" font="default" size="100%">Capote, Tiago</style></author><author><style face="normal" font="default" size="100%">Ribeiro, Teresa</style></author><author><style face="normal" font="default" size="100%">Santos, Conceição</style></author><author><style face="normal" font="default" size="100%">Gonçalves, Sónia</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Molecular characterization of Quercus suber MYB1, a transcription factor up-regulated in cork tissues</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Plant Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Alternative Splicing</style></keyword><keyword><style  face="normal" font="default" size="100%">Amino Acid Sequence</style></keyword><keyword><style  face="normal" font="default" size="100%">Cork biosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Cork oak</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes</style></keyword><keyword><style  face="normal" font="default" size="100%">Lipids</style></keyword><keyword><style  face="normal" font="default" size="100%">Lipids: biosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Molecular Sequence Data</style></keyword><keyword><style  face="normal" font="default" size="100%">phellogen</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Bark</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Bark: genetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Bark: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Growth Regulators</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Growth Regulators: biosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Proteins: chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Proteins: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: genetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">R2R3-MYB</style></keyword><keyword><style  face="normal" font="default" size="100%">RNA</style></keyword><keyword><style  face="normal" font="default" size="100%">Transcription Factors</style></keyword><keyword><style  face="normal" font="default" size="100%">Transcription Factors: chemistry</style></keyword><keyword><style  face="normal" font="default" size="100%">Transcription Factors: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Up-Regulation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/23218545http://linkinghub.elsevier.com/retrieve/pii/S0176161712004828</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">170</style></volume><pages><style face="normal" font="default" size="100%">1 - 7</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The molecular processes associated with cork development in Quercus suber L. are poorly understood. A previous molecular approach identiﬁed a list of genes potentially important for cork formation and differentiation, providing a new basis for further molecular studies. This report is the ﬁrst molecular characterization of one of these candidate genes, QsMYB1, coding for an R2R3-MYB transcription factor. The R2R3-MYB gene sub-family has been described as being involved in the phenylpropanoid and lignin pathways, both involved in cork biosynthesis. The results showed that the expression of QsMYB1 is putatively mediated by an alternative splicing (AS) mechanism that originates two different transcripts (QsMYB1.1 and QsMYB1.2), differing only in the 5 -untranslated region, due to retention of the ﬁrst intron in one of the variants. Moreover, within the retained intron, a simple sequence repeat (SSR) was identiﬁed. The upstream regulatory region of QsMYB1 was extended by a genome walking approach, which allowed the identiﬁcation of the putative gene promoter region. The relative expression pattern of QsMYB1 transcripts determined by reverse transcription quantitative polymerase chain reaction (RTqPCR) revealed that both transcripts were up-regulated in cork tissues; the detected expression was several times higher in newly formed cork harvested from trees producing virgin, second or reproduction cork when compared with wood. Moreover, the expression analysis of QsMYB1 in several Q. suber organs showed very low expression in young branches and roots, whereas in leaves, immature acorns or male ﬂowers, no expression was detected. These preliminary results suggest that QsMYB1 may be related to secondary growth and, in particular, with the cork biosynthesis process with a possible alternative splicing mechanism associated with its regulatory function.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;accession-num: 23218545</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Attia Al Hagrey, Said</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Geophysical imaging of root-zone, trunk, and moisture heterogeneity</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Experimental Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Electric Impedance</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrical resistivity techniques</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrodes</style></keyword><keyword><style  face="normal" font="default" size="100%">Geological Phenomena</style></keyword><keyword><style  face="normal" font="default" size="100%">Geology</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Roots</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Roots: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Populus</style></keyword><keyword><style  face="normal" font="default" size="100%">Populus: physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Portugal</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: anatomy &amp; histology</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Radar</style></keyword><keyword><style  face="normal" font="default" size="100%">radar imaging</style></keyword><keyword><style  face="normal" font="default" size="100%">ring electrode array</style></keyword><keyword><style  face="normal" font="default" size="100%">root-zone</style></keyword><keyword><style  face="normal" font="default" size="100%">sap flow</style></keyword><keyword><style  face="normal" font="default" size="100%">seismic tomography</style></keyword><keyword><style  face="normal" font="default" size="100%">trunk ring structure</style></keyword><keyword><style  face="normal" font="default" size="100%">vadose zone</style></keyword><keyword><style  face="normal" font="default" size="100%">water</style></keyword><keyword><style  face="normal" font="default" size="100%">water content</style></keyword><keyword><style  face="normal" font="default" size="100%">water flow</style></keyword><keyword><style  face="normal" font="default" size="100%">Water: analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Water: metabolism</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://jxb.oxfordjournals.org/content/58/4/839.abstracthttp://www.ncbi.nlm.nih.gov/pubmed/17229759</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">58</style></volume><pages><style face="normal" font="default" size="100%">839 - 854</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The most significant biotic and abiotic stress agents of water extremity, salinity, and infection lead to wood decay and modifications of moisture and ion content, and density. This strongly influences the (di-)electrical and mechanical properties and justifies the application of geophysical imaging techniques. These are less invasive and have high resolution in contrast to classical methods of destructive, single-point measurements for inspecting stresses in trees and soils. This review presents some in situ and in vivo applications of electric, radar, and seismic methods for studying water status and movement in soils, roots, and tree trunks. The electrical properties of a root-zone are a consequence of their moisture content. Electrical imaging discriminates resistive, woody roots from conductive, soft roots. Both types are recognized by low radar velocities and high attenuation. Single roots can generate diffraction hyperbolas in radargrams. Pedophysical relationships of water content to electrical resistivity and radar velocity are established by diverse infiltration experiments in the field, laboratory, and in the full-scale ‘GeoModel’ at Kiel University. Subsurface moisture distributions are derived from geophysical attribute models. The ring electrode technique around trunks images the growth ring structure of concentric resistivity, which is inversely proportional to the fluid content. Healthy trees show a central high resistivity within the dry heartwood that strongly decreases towards the peripheral wet sapwood. Observed structural deviations are caused by infection, decay, shooting, or predominant light and/or wind directions. Seismic trunk tomography also differentiates between decayed and healthy woods.</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><notes><style face="normal" font="default" size="100%">10.1093/jxb/erl23710.1093/jxb/erl237The following values have no corresponding Zotero field:&lt;br/&gt;accession-num: 17229759</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Filella, Iolanda</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author><author><style face="normal" font="default" size="100%">Llusia, Joan</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Dynamics of the enhanced emissions of monoterpenes and methyl salicylate, and decreased uptake of formaldehyde, by Quercus ilex leaves after application of jasmonic acid</style></title><secondary-title><style face="normal" font="default" size="100%">New Phytologist</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Carbon dioxide</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon Dioxide: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Cyclopentanes</style></keyword><keyword><style  face="normal" font="default" size="100%">Cyclopentanes: pharmacology</style></keyword><keyword><style  face="normal" font="default" size="100%">Dehydration</style></keyword><keyword><style  face="normal" font="default" size="100%">Formaldehyde</style></keyword><keyword><style  face="normal" font="default" size="100%">Formaldehyde: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">jasmonic acid (JA)</style></keyword><keyword><style  face="normal" font="default" size="100%">light</style></keyword><keyword><style  face="normal" font="default" size="100%">methyl salicylate</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpenes: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">net photosynthetic rates</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxylipins</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves: drug effects</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex (holm oak)</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: drug effects</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Salicylates</style></keyword><keyword><style  face="normal" font="default" size="100%">Salicylates: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">Temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">VOC (volatile organic compound)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2006///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/16390425http://dx.doi.org/10.1111/j.1469-8137.2005.01570.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">169</style></volume><pages><style face="normal" font="default" size="100%">135 - 144</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">* • Jasmonic acid (JA) is a signalling compound with a key role in both stress and development in plants, and is reported to elicit the emission of volatile organic compounds (VOCs). Here we studied the dynamics of such emissions and the linkage with photosynthetic rates and stomatal conductance. * • We sprayed JA on leaves of the Mediterranean tree species Quercus ilex and measured the photosynthetic rates, stomatal conductances, and emissions and uptake of VOCs using proton transfer reaction mass spectrometry and gas chromatography after a dark–light transition. * • Jasmonic acid treatment delayed the induction of photosynthesis and stomatal conductance by approx. 20 min, and decreased them 24 h after spraying. Indications were found of both stomatal and nonstomatal limitations of photosynthesis. Monoterpene emissions were enhanced (20–30%) after JA spraying. Jasmonic acid also increased methyl salicylate (MeSa) emissions (more than twofold) 1 h after treatment, although after 24 h this effect had disappeared. Formaldehyde foliar uptake decreased significantly 24 h after JA treatment. * • Both biotic and abiotic stresses can thus affect plant VOC emissions through their strong impact on JA levels. Jasmonic acid-mediated increases in monoterpene and MeSa emissions might have a protective role when confronting biotic and abiotic stresses.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Blackwell Publishing Ltd&lt;br/&gt;accession-num: 16390425</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ramírez, Carmen</style></author><author><style face="normal" font="default" size="100%">Testillano, Pilar S.</style></author><author><style face="normal" font="default" size="100%">Pintos, Beatriz</style></author><author><style face="normal" font="default" size="100%">Moreno-Risueño, Miguel a</style></author><author><style face="normal" font="default" size="100%">Bueno, María a</style></author><author><style face="normal" font="default" size="100%">Risueño, María C.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Changes in pectins and MAPKs related to cell development during early microspore embryogenesis in Quercus suber L.</style></title><secondary-title><style face="normal" font="default" size="100%">European journal of cell biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cell Differentiation</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Differentiation: physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron</style></keyword><keyword><style  face="normal" font="default" size="100%">MAPKs</style></keyword><keyword><style  face="normal" font="default" size="100%">Microscopy</style></keyword><keyword><style  face="normal" font="default" size="100%">microspore embryogenesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Mitogen-Activated Protein Kinase 1</style></keyword><keyword><style  face="normal" font="default" size="100%">Mitogen-Activated Protein Kinase 1: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Mitogen-Activated Protein Kinase 3</style></keyword><keyword><style  face="normal" font="default" size="100%">Mitogen-Activated Protein Kinase 3: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Mitogen-Activated Protein Kinases</style></keyword><keyword><style  face="normal" font="default" size="100%">Mitogen-Activated Protein Kinases: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Pectins</style></keyword><keyword><style  face="normal" font="default" size="100%">Pectins: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Proliferation</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: embryology</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: enzymology</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Seeds</style></keyword><keyword><style  face="normal" font="default" size="100%">Seeds: cytology</style></keyword><keyword><style  face="normal" font="default" size="100%">Seeds: ultrastructure</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/15346811</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">83</style></volume><pages><style face="normal" font="default" size="100%">213 - 225</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The occurrence and significance of changes in cell wall components and signalling molecules has been investigated during early microspore embryogenesis in cork oak (Quercus suber L.) in relation to cell proliferation and cell differentiation. Microspore embryogenesis has been induced in in vitro anther cultures of Q. suber by the application of a stress treatment of 33 degrees C. After the treatment, microspores at the responsive developmental stage of vacuolate microspore switched towards proliferation and the embryogenesis pathway to further produce haploid plantlets. Ultrastructural and immunocytochemical analysis revealed changes in cell organisation after induction at different developmental stages, the cellular features displayed being in relation to the activation of proliferative activity and the beginning of differentiation in young and late proembryos. Immunogold labelling with JIM5 and JIM7 antibodies showed a different presence of pectin and level of its esterification in cell walls at different developmental stages. Non-esterified pectins were found in higher proportions in cells of late proembryos, suggesting that pectin de-esterification could be related to the beginning of differentiation. The presence and subcellular distribution of Erk 1/2 MAPK homologues have been investigated by immunoblotting, immunofluorescence and immunogold labelling. The results showed an increase in the expression of these proteins with a high presence in the nucleus, during early microspore proembryos development. The reported changes during early microspore embryogenesis are modulated in relation to proliferation and differentiation events. These findings provided new evidences for a role of MAPK signalling pathways in early microspore embryogenesis, specifically in proliferation, and would confer information for the cell fate and the direction of the cell development.</style></abstract><issue><style face="normal" font="default" size="100%">5</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;accession-num: 15346811</style></notes></record></records></xml>