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Plant functional traits and community assembly along interacting gradients of productivity and fragmentation 总被引:2,自引:0,他引:2
Felix May Itamar Giladi Michael Ristow Yaron Ziv Florian Jeltsch 《Perspectives in Plant Ecology, Evolution and Systematics》2013,15(6):304-318
Quantifying the association of plant functional traits to environmental gradients is a promising approach for understanding and projecting community responses to land use and climatic changes. Although habitat fragmentation and climate are expected to affect plant communities interactively, there is a lack of empirical studies addressing trait associations to fragmentation in different climatic regimes.In this study, we analyse data on the key functional traits: specific leaf area (SLA), plant height, seed mass and seed number. First, we assess the evidence for the community assembly mechanisms habitat filtering and competition at different spatial scales, using several null-models and a comprehensive set of community-level trait convergence and divergence indices. Second, we analyse the association of community-mean traits with patch area and connectivity along a south–north productivity gradient.We found clear evidence for trait convergence due to habitat filtering. In contrast, the evidence for trait divergence due to competition fundamentally depended on the null-model used. When the null-model controlled for habitat filtering, there was only evidence for trait divergence at the smallest sampling scale (0.25 m × 0.25 m). All traits varied significantly along the S–N productivity gradient. While plant height and SLA were consistently associated with fragmentation, the association of seed mass and seed number with fragmentation changed along the S–N gradient.Our findings indicate trait convergence due to drought stress in the arid sites and due to higher productivity in the mesic sites. The association of plant traits to fragmentation is likely driven by increased colonization ability in small and/or isolated patches (plant height, seed number) or increased persistence ability in isolated patches (seed mass).Our study provides the first empirical test of trait associations with fragmentation along a productivity gradient. We conclude that it is crucial to study the interactive effects of different ecological drivers on plant functional traits. 相似文献
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The availability of the complete genome sequences has facilitated access to essential information to identify proteins. The determination of Arabidopsis genome sequence has had a great impact to annotate data. The genome sequencing of Sorghum bicolor has been only recently completed and hither to the global response to abiotic stresses in this important crop remains largely unexplored. We used 2-D gel electrophoresis based proteomic approach refined with MALDI-TOF to analyze drought-stress response proteins in sorghum. Major changes in protein complement of sorghum were observed in hydroponic cultures at 96 hours under drought stress. Six most highly expressed proteins were excised for functional identification. Here, we developed a method to obtain functional distances between GO terms and analyzed distance values to allocate shortest path (SP) in GO hierarchy. The shortest paths for expressed proteins were noted for most informative common ancestor (MICA) terms, viz. binding, catalytic activity and primary metabolic process. We observed the expressed proteins belonged to the functional group of signal transduction mechanisms, carbohydrate transport and metabolism. These identified functions of proteins suggest a different mechanism of drought-stress tolerant in sorghum. The novel approach applied in this study may have great importance in further identifying proteins involved in abiotic and biotic stress conditions in crops. 相似文献
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This study characterized morphological and physiological responses of two Malus species to exogenous abscisic acid (ABA) application under both well-watered and drought-stressed conditions. Exogenous ABA
was sprayed onto the leaves of potted 1-year-old seedlings of M. sieversii and M. hupehensis, originated from regions with low annual rainfall and high annual rainfall, respectively. The results demonstrated that exogenous
ABA application significantly decreased height growth (H), total biomass (TB), total leaf area (LA), net photosynthesis (A) and stomatal conductance (g
s), and significantly increased root/shoot ratio (RS), specific leaf area (SLA), endogenous ABA concentration, water use efficiency
(WUE) and carbon isotope composition (δ13C) under both well-watered and drought-stressed conditions. However, distinct interspecific differences were found in ABA-induced
morphological and physiological responses. Compared with M. hupehensis, M. sieversii was more responsive to exogenous ABA application, resulting in larger decreases in H, LA, A and g
s, and larger increases in RS, SLA, WUEL, WUEi, ABA and δ13C. These results suggest strong evidence for different maintenance of fitness under stressful conditions between species of
Malus. In addition, application of exogenous ABA appears to enhance the tolerance of two Malus species to drought-stress. 相似文献
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Adrian J. Charlton James A. Donarski Mark Harrison Stephen A. Jones John Godward Sarah Oehlschlager Juan L. Arques Mike Ambrose Catherine Chinoy Philip M. Mullineaux Claire Domoney 《Metabolomics : Official journal of the Metabolomic Society》2008,4(4):312-327
While many compounds have been reported to change in laboratory based drought-stress experiments, little is known about how
such compounds change, and are significant, under field conditions. The Pisum sativum L. (pea) leaf metabolome has been profiled, using 1D and 2D NMR spectroscopy, to monitor the changes induced by drought-stress,
under both glasshouse and simulated field conditions. Significant changes in resonances were attributed to a range of compounds,
identified as both primary and secondary metabolites, highlighting metabolic pathways that are stress-responsive. Importantly,
these effects were largely consistent among different experiments with highly diverse conditions. The metabolites that were
present at significantly higher concentrations in drought-stressed plants under all growth conditions included proline, valine,
threonine, homoserine, myoinositol, γ-aminobutyrate (GABA) and trigonelline (nicotinic acid betaine). Metabolites that were
altered in relative amounts in different experiments, but not specifically associated with drought-stress, were also identified.
These included glutamate, asparagine and malate, with the last being present at up to 5-fold higher concentrations in plants
grown in field experiments. Such changes may be expected to impact both on plant performance and crop end-use.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Water relations of rough lemon (Citrus jambhiri Lush.) citrus seedlings infected withFusarium solani
Summary Rough lemon citrus seedlings were inoculated withFusarium solani and evaluated for changes in water relations of leaves, stems, and roots. Inoculated seedlings had decreased leaf stomatal
conductance, lower leaf water potential, lower water content, and higher leaf osmotic values compared to healthy plants. Visible
wilt symptoms occurred as early as 24 h after inoculation. Transpiration and root conductivity were lower in diseased plants
but stem conductivity in diseased plants did not differ from the control. Thus, wilting appears to be due to the inability
of roots to supply water to the leaves. 相似文献
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Yamaguchi K Takahashi Y Berberich T Imai A Takahashi T Michael AJ Kusano T 《Biochemical and biophysical research communications》2007,352(2):486-490
Cellular polyamine content often changes in response to abiotic stresses. However, its physiological relevance is unknown. We found that an Arabidopsis mutant plant (acl5/spms), which cannot produce spermine, is hypersensitive to high salt. Examination of drought sensitivity of the mutant and comparison with wild type plants indicated hypersensitivity to drought. This phenotype was cured by spermine pretreatment but not by the other polyamines putrescine and spermidine, suggesting that drought-hypersensitivity exhibited by the mutant is due to spermine deficiency. The water loss rate of wild type and mutant plants were similar until 20 min after onset of dehydration stress, but after a longer exposure the rate in mutant plants was higher than in wild type plants. Consistent with this result, the stomata of the mutant leaves remained open while in wild type leaves they closed. Based on the collected data, we discuss a role for spermine in response to drought stress. 相似文献
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To investigate the function of nuclear-localized plant HSP70, we used NtHSP70-1 isolated from Nicotiana tabacum. The subcellular localization of NtHSP70-1 was identified by fluorescence microscopy for NtHSP70-1/GFP or smGFP fusion proteins
in onion epidermal cells, obtained using particle gun bombardment. To analyze the drought-stress tolerance and thermoprotective
role of NtHSP70-1, we obtained transgenic tobacco plants that constitutively expressed elevated levels of NtHSP70-1 as well
as transgenic plants containing either the vector alone or else having NtHSP70-1 in the antisense orientation. From analysis
for genomic DNA in transgenic seedlings after heat stress, NtHSP70-1 helps to prevent the fragmentation and degradation of
nuclear DNA during heat stress. In addition, seedlings constitutively overexpressing NtHSP70-1 grew to be healthy plants,
whereas transgenic vector or antisense seedlings resulted in death after heat-/drought-stress. 相似文献
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Groundnut (Arachis hypogea L.), is an important legume cash crop for the tropical farmers and its seeds contain high amounts of edible oil (43–55%) and protein (25–28%). Even though it is a fairly drought-tolerant, production fluctuates considerably as a result of rainfall variability. To develop a water stress response function in groundnut, research works have been done to improve the performance under varying degrees of stress at various physiological stages of crop growth. This review summarizes recent information on drought resistance characteristics of groundnut with a view toward developing appropriate genetic enhancement strategies for water-limited environments. It is suggested that there are considerable gains to be made in increasing yield and stabilizing the yield in environments characterized by terminal drought stress and by shortening crop duration. Many traits conferring dehydration avoidance and dehydration tolerance are available, but integrated traits, expressing at a high level of organization are suggested to be more useful in crop improvement programs. Possible genetic improvement strategies are outlined, ranging from empirical selection for yield in drought environments to a physiological–genetic approach. It was also suggested that in view of recent advances in understanding drought resistance mechanisms, the later strategy is becoming more feasible. It is summarized that application of knowledge into practice in a systematic manner can lead to significant gains in yield and yield stability of the worlds groundnuts production. Research is needed to develop transferable technology to help farmers of arid and semi-arid regions. Increasing soil moisture storage by soil profile management and nutrient management for quick recovery from drought are some of the areas that need to be explored further. 相似文献
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