Project description:Transcript profiling of leaves from Quercus ilex seedlings subjected to well-watering and drought-stress (irrigation withdrawal) conditions
Project description:Proteases and protease inhibitors have been analyzed in the non-orthodox Quercus ilex forest tree by using in silico and wet approaches. The in silico analysis showed that the species-specific transcriptome database included 2240 and 97 transcripts annotated as, respectively, proteases and protease inhibitors, with members of the different families according to the MEROPS protease database (http://www.merops.ac.uk) classification, mostly of serine- and metallo-type. Data for Q. ilex are compared with those previously published for other Quercus species, namely, Q. suber, Q. lobata, and Q. robur. A second approach was performed to assess the evolution of proteases and protease inhibitors along with seed germination in cotyledon and embryo tissues by determining changes at proteomics and activity levels, the last by mean of in vitro and in gel assays. Shotgun (LC-MSMS) analysis of acorn embryos and cotyledons of three developmental stages (NV, non-viable; T1, mature; and T3 germinated) allowed the identification of a total of 177 proteases and 12 protease inhibitors. In vitro protease activity was determined by using azocasein as substrate; the total activity was higher in cotyledons than embryos, showing the latter significant differences throughout germination. Gel protease activity assays showed common and differential bands between tissues and developmental stages. Shotgun analysis of 10 differential activity bands supported the results obtained from the whole proteome analysis, with some proteins highly represented in the same tissues and stages by both strategies. In overall, the combination of shotgun proteomics and protease activity approaches allowed the identification of tissue-specific (such as cysteine protease inhibitors), and stage-specific proteins (such as those related to storage proteins mobilization), with others being present in all the analyzed organs. Some of the proteases and protease inhibitors differentially identified between tissues and stages in this study could be used as indicators of seed quality and viability.
Project description:Applying a gel-based proteomic approach, the dynamic changes in root proteins of drought treated Quercus ilex subsp. Ballota [Desf.] Samp. seedlings were followed. Water stress was applied on 20 day-old holm oak plantlets by water limitation for a period of 10 and 20 days, each followed by 10 days of recovery. Root proteins were extracted using trichloroacetate/acetone/phenol protocol and subjected to two-dimensional electrophoresis. Coomassie colloidal stained gel images were analysed and spot intensity data subjected to multivariate statistical analysis. Selected consistent spots in the three biological replicas, presenting significant changes under stress, were subjected to MALDI-TOF mass spectrometry (peptide mass fingerprinting and MS/MS). For protein identification, combined search was performed with MASCOT search engine over NCBInr Viridiplantae and Uniprot databases. Taxonomy Holm oak (Quercus ilex subsp. Ballota [Desf.] Samp.). Dentro de Q. ilex hay dos subespecies, ilex ilex e ilex Ballota.