Bioresources 4 Sustainability

Funder

Organizational Unit

Publications

Characterization of the cork oak transcriptome dynamics during acorn development

Publication . Miguel, Andreia; de Vega-Bartol, José; Marum, Liliana; Chaves, Inês; Santo, Tatiana; Leitão, J. M.; Varela, Maria C.; Miguel, Célia M.

Background: Cork oak (Quercus suber L.) has a natural distribution across western Mediterranean regions and is a keystone forest tree species in these ecosystems. The fruiting phase is especially critical for its regeneration but the molecular mechanisms underlying the biochemical and physiological changes during cork oak acorn development are poorly understood. In this study, the transcriptome of the cork oak acorn, including the seed, was characterized in five stages of development, from early development to acorn maturation, to identify the dominant processes in each stage and reveal transcripts with important functions in gene expression regulation and response to water. Results: A total of 80,357 expressed sequence tags (ESTs) were de novo assembled from RNA-Seq libraries representative of the several acorn developmental stages. Approximately 7.6 % of the total number of transcripts present in Q. suber transcriptome was identified as acorn specific. The analysis of expression profiles during development returned 2,285 differentially expressed (DE) transcripts, which were clustered into six groups. The stage of development corresponding to the mature acorn exhibited an expression profile markedly different from other stages. Approximately 22 % of the DE transcripts putatively code for transcription factors (TF) or transcriptional regulators, and were found almost equally distributed among the several expression profile clusters, highlighting their major roles in controlling the whole developmental process. On the other hand, carbohydrate metabolism, the biological pathway most represented during acorn development, was especially prevalent in mid to late stages as evidenced by enrichment analysis. We further show that genes related to response to water, water deprivation and transport were mostly represented during the early (S2) and the last stage (S8) of acorn development, when tolerance to water desiccation is possibly critical for acorn viability. Conclusions: To our knowledge this work represents the first report of acorn development transcriptomics in oaks. The obtained results provide novel insights into the developmental biology of cork oak acorns, highlighting transcripts putatively involved in the regulation of the gene expression program and in specific processes likely essential for adaptation. It is expected that this knowledge can be transferred to other oak species of great ecological value.

2015-06-25Journal article

Open Access

Microeconomic and environmental sustainability of Portuguese greenhouse horticulture: a critical assessment

Publication . Costa, J. M.; Reis, Mário; Passarinho, J. A.; Ferreira, M. E.; Almeida, D. P. F.

Estimated total greenhouse production area in Portugal is 3,000 ha. The potential for expansion of the sector exists, but it must minimize undesirable environmental impacts, while taking advantage of related economic benefits. In 2013, greenhouse production represented only 6% of the total commercial vegetable production area but it accounted for about 16% of total production. Moreover, total production value per greenhouse farm is about 91,200 euro, almost twice that of open-air production. However, the sector misses a detailed quantitative analysis of sustainability, considering its environmental impact, resource use efficiency and economic performance. In this study we provide a preliminary comprehensive analysis of the major inputs and outputs of greenhouse horticulture, focusing on the tomato crop. A simplified life cycle analysis was implemented. Irrigation water needs by the tomato crop vary between 20 and 39 L kg-1 (fresh weight), whereas the estimated output in terms of plastic film residues (covering films), is about 2,060 t per year. In addition, an amount of 56,000 to 70,000 t is calculated for organic residues. The quantity and quality of the produced effluents remain uncharacterized, but drainage (20 to 40% of irrigation in soilless systems) will be the main contributor. Stricter EU legislation and more demanding consumers impose a more efficient greenhouse management to minimize pollution risks. Greenhouse cultivation in Portugal is productive and profitable and it has room for expansion, but input use efficiencies need improvement to reduce its environmental impact and increase sustainability of this sector.

2017Journal article

Restricted