scispace - formally typeset
Search or ask a question
Institution

Instituto Superior de Agronomia

About: Instituto Superior de Agronomia is a based out in . It is known for research contribution in the topics: Population & Quercus suber. The organization has 1560 authors who have published 3358 publications receiving 113235 citations.
Topics: Population, Quercus suber, Cork, Soil water, Wine


Papers
More filters
Journal ArticleDOI
TL;DR: The basic ideas of PCA are introduced, discussing what it can and cannot do, and some variants of the technique have been developed that are tailored to various different data types and structures.
Abstract: Large datasets are increasingly common and are often difficult to interpret. Principal component analysis (PCA) is a technique for reducing the dimensionality of such datasets, increasing interpretability but at the same time minimizing information loss. It does so by creating new uncorrelated variables that successively maximize variance. Finding such new variables, the principal components, reduces to solving an eigenvalue/eigenvector problem, and the new variables are defined by the dataset at hand, not a priori , hence making PCA an adaptive data analysis technique. It is adaptive in another sense too, since variants of the technique have been developed that are tailored to various different data types and structures. This article will begin by introducing the basic ideas of PCA, discussing what it can and cannot do. It will then describe some variants of PCA and their application.

4,289 citations

Journal ArticleDOI
TL;DR: Attention is drawn to the perception and signalling processes (chemical and hydraulic) of water deficits, which are essential for a holistic understanding of plant resistance to stress, which is needed to improve crop management and breeding techniques.
Abstract: In the last decade, our understanding of the processes underlying plant response to drought, at the molecular and whole-plant levels, has rapidly progressed. Here, we review that progress. We draw attention to the perception and signalling processes (chemical and hydraulic) of water deficits. Knowledge of these processes is essential for a holistic understanding of plant resistance to stress, which is needed to improve crop management and breeding techniques. Hundreds of genes that are induced under drought have been identified. A range of tools, from gene expression patterns to the use of transgenic plants, is being used to study the specific function of these genes and their role in plant acclimation or adaptation to water deficit. However, because plant responses to stress are complex, the functions of many of the genes are still unknown. Many of the traits that explain plant adaptation to drought - such as phenology, root size and depth, hydraulic conductivity and the storage of reserves - are those associated with plant development and structure, and are constitutive rather than stress induced. But a large part of plant resistance to drought is the ability to get rid of excess radiation, a concomitant stress under natural conditions. The nature of the mechanisms responsible for leaf photoprotection, especially those related to thermal dissipation, and oxidative stress are being actively researched. The new tools that operate at molecular, plant and ecosystem levels are revolutionising our understanding of plant response to drought, and our ability to monitor it. Techniques such as genome-wide tools, proteomics, stable isotopes and thermal or fluorescence imaging may allow the genotype-phenotype gap to be bridged, which is essential for faster progress in stress biology research.

3,287 citations

Journal ArticleDOI
TL;DR: It is becoming apparent that plants perceive and respond to drought and salt stresses by quickly altering gene expression in parallel with physiological and biochemical alterations; this occurs even under mild to moderate stress conditions.

3,080 citations

Journal ArticleDOI
TL;DR: Differences among species that can be traced to different capacities for water acquisition, rather than to differences in metabolism at a given water status, are described.

1,838 citations

Journal ArticleDOI
TL;DR: The major constraints to carbon assimilation and the metabolic regulations that play a role in plant responses to water deficits, acting in isolation or in conjunction with other stresses, is reviewed.
Abstract: Drought is one of the greatest limitations to crop expansion outside the present-day agricultural areas. It will become increasingly important in regions of the globe where, in the past, the problem was negligible, due to the recognized changes in global climate. Today the concern is with improving cultural practices and crop genotypes for drought-prone areas; therefore, understanding the mechanisms behind drought resistance and the efficient use of water by the plants is fundamental for the achievement of those goals. In this paper, the major constraints to carbon assimilation and the metabolic regulations that play a role in plant responses to water deficits, acting in isolation or in conjunction with other stresses, is reviewed. The effects on carbon assimilation include increased resistance to diffusion by stomata and the mesophyll, as well as biochemical and photochemical adjustments. Oxidative stress is critical for crops that experience drought episodes. The role of detoxifying systems in preventing irreversible damage to photosynthetic machinery and of redox molecules as local or systemic signals is revised. Plant capacity to avoid or repair membrane damage during dehydration and rehydration processes is pivotal for the maintenance of membrane integrity, especially for those that embed functional proteins. Among such proteins are water transporters, whose role in the regulation of plant water status and transport of other metabolites is the subject of intense investigation. Long-distance chemical signalling, as an early response to drought, started to be unravelled more than a decade ago. The effects of those signals on carbon assimilation and partitioning of assimilates between reproductive and non-reproductive structures are revised and discussed in the context of novel management techniques. These applications are designed to combine increased crop water-use efficiency with sustained yield and improved quality of the products. Through an understanding of the mechanisms leading to successful adaptation to dehydration and rehydration, it has already been possible to identify key genes able to alter metabolism and increase plant tolerance to drought. An overview of the most important data on this topic, including engineering for osmotic adjustment or protection, water transporters, and C4 traits is presented in this paper. Emphasis is given to the most successful or promising cases of genetic engineering in crops, using functional or regulatory genes. as well as to promising technologies, such as the transfer of transcription factors.

1,197 citations


Authors

Showing all 1560 results

NameH-indexPapersCitations
Helena Santos114105854286
Ülo Niinemets10143940555
João Rocha93152149472
Luis S. Pereira6831735582
João Pereira6825620837
James F. Reynolds6316219524
Maurizio Mencuccini6321815920
Isabel M.P.L.V.O. Ferreira5847911982
John H. C. Gash5710612175
Helena Pereira5746714876
Henrique M. Pereira5516714397
Maria Manuela Chaves5012118135
José M. C. Pereira491918325
João Maroco4837512764
Francisco Moreira461797107
Network Information
Related Institutions (5)
Wageningen University and Research Centre
54.8K papers, 2.6M citations

92% related

Institut national de la recherche agronomique
68.3K papers, 3.2M citations

91% related

University of Hohenheim
16.4K papers, 567.3K citations

91% related

Nanjing Agricultural University
27.3K papers, 546.5K citations

90% related

Swedish University of Agricultural Sciences
35.2K papers, 1.4M citations

90% related

Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20224
2021274
2020248
2019248
2018220
2017203