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341.
Lander Baeten Margot Vanhellemont Pieter De Frenne An De Schrijver Martin Hermy Kris Verheyen 《Oecologia》2010,163(4):1021-1032
The differential ability of forest herbs to colonize secondary forests on former agricultural land is generally attributed
to different rates of dispersal. After propagule arrival, however, establishing individuals still have to cope with abiotic
soil legacies from former agricultural land use. We focused on the plastic responses of forest herbs to increased phosphorus
availability, as phosphorus is commonly found to be persistently bioavailable in post-agricultural forest soils. In a pot
experiment performed under field conditions, we applied three P levels to four forest herbs with contrasting colonization
capacities: Anemone nemorosa, Primula elatior, Circaea lutetiana and Geum urbanum. To test interactions with light availability, half of the replicas were covered with shade cloths. After two growing seasons,
we measured aboveground P uptake as well as vegetative and regenerative performance. We hypothesized that fast-colonizing
species respond the most opportunistically to increased P availability, and that a low light availability can mask the effects
of P on performance. All species showed a significant increase in P uptake in the aboveground biomass. The addition of P had
a positive effect on the vegetative performances of two of the species, although this was unrelated to their colonization
capacities. The regenerative performance was affected by light availability (not by P addition) and was related to the species’
phenology. Forest herbs can obviously benefit from the increased availability of P in post-agricultural forests, but not all
species respond in the same way. Such differential patterns of plasticity may be important in community dynamics, as they
affect the interactions among species. 相似文献
342.
Dun Wang Xiao‐Fei Li Zheng‐Jian Zhou Xu‐Ping Feng Wan‐Jun Yang De‐An Jiang 《Physiologia plantarum》2010,139(1):55-67
Studies on some plant species have shown that increasing the growth temperature gradually or pretreating with high temperature can lead to obvious photosynthetic acclimation to high temperature. To test whether this acclimation arises from heat adaptation of ribulose 1,5‐bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) activation mediated by Rubisco activase (RCA), gene expression of RCA large isoform (RCAL) and RCA small isoform (RCAS) in rice was determined using a 4‐day heat stress treatment [40/30°C (day/night)] followed by a 3‐day recovery under control conditions [30/22°C (day/night)]. The heat stress significantly induced the expression of RCAL as determined by both mRNA and protein levels. Correlative analysis indicated that RCAS protein content was extremely significantly related to Rubisco initial activity and net photosynthetic rate (Pn) under both heat stress and normal conditions. Immunoblot analysis of the Rubisco–RCA complex revealed that the ratio of RCAL to Rubisco increased markedly in heat‐acclimated rice leaves. Furthermore, transgenic rice plants expressing enhanced amounts of RCAL exhibited higher thermotolerance in Pn and Rubisco initial activity and grew better at high temperature than wild‐type (WT) plants and transgenic rice plants expressing enhanced amounts of RCAS. Under normal conditions, the transgenic rice plants expressing enhanced amounts of RCAS showed higher Pn and produced more biomass than transgenic rice plants expressing enhanced amounts of RCAL and wild‐type plants. Together, these suggest that the heat‐induced RCAL may play an important role in photosynthetic acclimation to moderate heat stress in vivo, while RCAS plays a major role in maintaining Rubisco initial activity under normal conditions. 相似文献
343.
344.
ΔfosB是fosB基因的自然截短型,稳定存在于许多组织中,在脂肪细胞和成骨细胞的形成和分化中起到重要作用。ΔFosB蛋白可能与钙在骨和乳腺中的代谢有关,并且调控钙从骨向乳腺转移的信号通路。将奶山羊的ΔfosB基因亚克隆到pET32a载体得到pET32a-ΔfosB原核表达载体,IPTG诱导其在大肠杆菌中表达,纯化融合蛋白免疫兔子制备多克隆抗体。ELISA检测显示抗体效价达1:51200,Western blotting结果显示制备的抗体能特异性检测原核表达的ΔFosB蛋白以及在HEK-293细胞中表达的ΔFosB蛋白。进一步的组织差异表达检测表明ΔFosB在山羊的乳腺、骨髓、脑髓、肌肉、心脏、肝和肺组织中均有表达。 相似文献
345.
346.
A minimal linear gene cassette (35S-phytase gene-nos) with T-DNA borders was acquired by PCR and directly introduced into
soybean through the pollen tube pathway. A total of 13% of T1 plants were positive for phyA by specific PCR. Southern blot analyses showed that phyA insertions were harbored stably in T2 progeny. Phytase expression level increased 2.5-fold over a 6-week period; its highest activity was 150 U/mg protein, compared
to 56 U/mg protein in untransformed controls. Activity of phytase increased to 125 FTU/kg in T3 transgenic seeds as compared to 64 FTU/kg in wild-type plants. 相似文献
347.
T-DNA-tagged rice plants were screened under cold- or salt-stress conditions to determine the genes involved in the molecular
mechanism for their abiotic-stress response. Line 0-165-65 was identified as a salt-responsive line. The gene responsible
for this GUS-positive phenotype was revealed by inverse PCR as OsGSK1 (O
ryza
s
ativa
g
lycogen
s
ynthase
k
inase3-like gene
1), a member of the plant GSK3/SHAGGY-like protein kinase genes and an orthologue of the Arabidopsis
b
rassinosteroid
in
sensitive
2
(BIN2), AtSK21. Northern blot analysis showed that OsGSK1 was most highly detected in the developing panicles, suggesting that its expression is developmental stage specific. Knockout
(KO) mutants of OsGSK1 showed enhanced tolerance to cold, heat, salt, and drought stresses when compared with non-transgenic segregants (NT). Overexpression
of the full-length OsGSK1 led to a stunted growth phenotype similar to the one observed with the gain-of-function BIN/AtSK21 mutant. This suggests that OsGSK1 might be a functional rice orthologue that serves as a negative regulator of brassinosteroid (BR)-signaling. Therefore, we
propose that stress-responsive OsGSK1 may have physiological roles in stress signal-transduction pathways and floral developmental processes.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Serry Koh and Sang-Choon Lee are co-first authors. 相似文献
348.
Wiley PR Tosi P Evrard A Lovegrove A Jones HD Shewry PR 《Plant molecular biology》2007,65(1-2):125-136
Increasing its root to shoot ratio is a plant strategy for restoring water homeostasis in response to the long-term imposition
of mild water stress. In addition to its important role in diverse fundamental processes, indole-3-acetic acid (IAA) is involved
in root growth and development. Recent extensive characterizations of the YUCCA gene family in Arabidopsis and rice have elucidated that member’s function in a tryptophan-dependent IAA biosynthetic pathway. Through forward- and
reverse-genetics screening, we have isolated Tos17 and T-DNA insertional rice mutants in a CONSTITUTIVELY WILTED1 (COW1) gene, which encodes a new member of the YUCCA protein family. Homozygous plants with either a Tos17 or T-DNA-inserted allele of OsCOW1 exhibit phenotypes of rolled leaves, reduced leaf widths, and lower root to shoot ratios. These phenotypes are evident in
seedlings as early as 7–10 d after germination, and remain until maturity. When oscow1 seedlings are grown under low-intensity light and high relative humidity, the rolled-leaf phenotype is greatly alleviated.
For comparison, in such conditions, the transpiration rate for WT leaves decreases approx. 5- to 10-fold, implying that this
mutant trait results from wilting rather than being a morphogenic defect. Furthermore, a lower turgor potential and transpiration
rate in their mature leaves indicates that oscow1 plants are water-deficient, due to insufficient water uptake that possibly stems from that diminished root to shoot ratio.
Thus, our observations suggest that OsCOW1-mediated IAA biosynthesis plays an important role in maintaining root to shoot ratios and, in turn, affects water homeostasis
in rice. 相似文献
349.
Hydrogen peroxide (H2O2), an active oxygen species, is widely generated in many biological systems. The present study demonstrates that H2O2 was generated in seedling explants after the primary roots were removed, and it mediates the auxin response prior to adventitious
root formation in cucumber (Cucumis sativus L. Ganfeng 8). When compared with the controls, treatment of cucumber seedling explants after primary roots removal with
either 20–40 mM H2O2 or 10 μM IAA significantly increased the number of adventitious roots, and treatment with 10–50 mM H2O2 significantly increased the fresh weight of adventitious roots. The effects of H2O2 on promoting the formation and growth of adventitious roots were eliminated by 2 mM ascorbic acid, 100 U CAT or 1 μM DPI,
and the effects of IAA were eliminated by 4 mM ascorbic acid, 100 U CAT or 5 μM DPI. Treatment with either 4 mM ascorbic acid
or 1–5 μM DPI inhibited the formation and growth of adventitious roots, and these inhibitory effects were partly reversed
by exogenous H2O2.Furthermore, a higher concentration of endogenous H2O2 was detected in seedling explants 3 h after the primary roots were removed. However, in 10 μM DPI-treated seedling explants,
the concentration of endogenous H2O2 was markedly reduced by DPI. Results obtained suggest that H2O2 may function as a signaling molecule, involved in the formation and development of adventitious roots in cucumber. 相似文献
350.
Method of site-directed mutagenesis that gave an opportunity to the site-independent manipulation with enough extended exposed mutagenesis fragments of gene cloning in plasmid vector was developed. With the help of this method hybrid constructions representing peas Pisum sativum (PSL) lectine with carbohydrate-binding fragment changing on that lectines from another legume plants were created. This method is suitable for obtaining the expression constructions in plasmid vectors, when is necessary to put a coding part under the control of promoter in a certain reading frame. 相似文献