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71.
GUOWEI LI MARIE BOUDSOCQ SONIA HEM JÉRÔME VIALARET MICHEL ROSSIGNOL CHRISTOPHE MAUREL VÉRONIQUE SANTONI 《Plant, cell & environment》2015,38(7):1312-1320
The hydraulic conductivity of plant roots (Lpr) is determined in large part by the activity of aquaporins. Mechanisms occurring at the post‐translational level, in particular phosphorylation of aquaporins of the plasma membrane intrinsic protein 2 (PIP2) subfamily, are thought to be of critical importance for regulating root water transport. However, knowledge of protein kinases and phosphatases acting on aquaporin function is still scarce. In the present work, we investigated the Lpr of knockout Arabidopsis plants for four Ca2+‐dependent protein kinases. cpk7 plants showed a 30% increase in Lpr because of a higher aquaporin activity. A quantitative proteomic analysis of wild‐type and cpk7 plants revealed that PIP gene expression and PIP protein quantity were not correlated and that CPK7 has no effect on PIP2 phosphorylation. In contrast, CPK7 exerts a negative control on the cellular abundance of PIP1s, which likely accounts for the higher Lpr of cpk7. In addition, this study revealed that the cellular amount of a few additional proteins including membrane transporters is controlled by CPK7. The overall work provides evidence for CPK7‐dependent stability of specific membrane proteins. 相似文献
72.
Among long-lived bird species, the partners of breeding pairs are often of similar age. This pattern is largely influenced by little variation in the age at first breeding, linked with high survival rate and prolonged pair bonds. Contrary to other long-lived colonial species, Greater Flamingos Phoenicopterus ruber roseus do not show mate fidelity over consecutive breeding seasons. We studied pairing patterns of Greater Flamingos breeding in the Camargue, southern France, between December 1989 and March 1992. In each year, significant correlations were observed between the ages of the male and the female in a pair. The pattern of age-assortative mating was confirmed independently in each year by comparing the frequency distribution of age differences within pairs with the theoretical distribution derived from the age distribution of paired birds of known age in the population, assuming random pairing with respect to age. There was no evidence of a differential time of return each year to the colony with age. Analysis of display behaviour suggested that age-as-sortative mating in the Greater Flamingo results from a directional pairing preference for older and more experienced individuals. The present study provides direct evidence that age-assortative mating can occur independently of mate fidelity. 相似文献
73.
Although climate change will alter both soil water availability and evaporative demand, our understanding of how future climate conditions will alter tree hydraulic architecture is limited. Here, we demonstrate that growth at elevated temperatures (ambient +5 °C) affects hydraulic traits in seedlings of the deciduous boreal tree species Populus tremuloides, with the strength of the effect varying with the plant organ studied. Temperature altered the partitioning of hydraulic resistance, with greater resistance attributed to stems and less to roots in warm‐grown seedlings (P < 0.02), and a 46% (but marginally significant, P = 0.08) increase in whole plant conductance at elevated temperature. Vulnerability to cavitation was greater in leaves grown at high than at ambient temperatures, but vulnerability in stems was similar between treatments. A soil–plant–atmosphere (SPA) model suggests that these coordinated changes in hydraulic physiology would lead to more frequent drought stress and reduced water‐use efficiency in aspen that develop at warmer temperatures. Tissue‐specific trade‐offs in hydraulic traits in response to high growth temperatures would be difficult to detect when relying solely on whole plant measurements, but may have large‐scale ecological implications for plant water use, carbon cycling and, possibly, plant drought survival. 相似文献
74.
VICTOR H. GONZALEZ TERRY GRISWOLD CHRISTOPHE J. PRAZ BRYAN N. DANFORTH 《Systematic Entomology》2012,37(2):261-286
Phylogenetic relationships within the bee family Megachilidae are poorly understood. The monophyly of the subfamily Fideliinae is questionable, the relationships among the tribes and subtribes in the subfamily Megachilinae are unknown, and some extant genera cannot be placed with certainty at the tribal level. Using a cladistic analysis of adult external morphological characters, we explore the relationships of the eight tribes and two subtribes currently recognised in Megachilidae. Our dataset included 80% of the extant generic‐level diversity, representatives of all fossil taxa, and was analysed using parsimony. We employed 200 characters and selected 7 outgroups and 72 ingroup species of 60 genera, plus 7 species of 4 extinct genera from Baltic amber. Our analysis shows that Fideliinae and the tribes Anthidiini and Osmiini of Megachilinae are paraphyletic; it supports the monophyly of Megachilinae, including the extinct taxa, and the sister group relationship of Lithurgini to the remaining megachilines. The Sub‐Saharan genus Aspidosmia, a rare group with a mixture of osmiine and anthidiine features, is herein removed from Anthidiini and placed in its own tribe, Aspidosmiini, new tribe . Protolithurgini is the sister of Lithurgini, both placed herein in the subfamily Lithurginae; the other extinct taxa, Glyptapina and Ctenoplectrellina, are more basally related among Megachilinae than Osmiini, near Aspidosmia, and are herein treated at the tribal level. Noteriades, a genus presently in the Osmiini, is herein transferred to the Megachilini. Thus, we recognise four subfamilies (Fideliinae, Pararhophitinae, Lithurginae and Megachilinae) and nine tribes in Megachilidae. We briefly discuss the evolutionary history and biogeography of the family, present alternative classifications, and provide a revised key to the extant tribes of Megachilinae. 相似文献
75.
76.
CHRISTOPHE AMIOT OLIVIER LORVELEC ISABELLE MANDON-DALGER ANTONIA SARDELLA PATRICIA LEQUILLIEC & PHILIPPE CLERGEAU 《Ibis》2007,149(3):482-489
New environmental conditions may impact on behaviour and morphology, and consequently affect population dynamics. Rapid response to new conditions is likely to be a key factor in species introduction success. The Red-whiskered Bulbul Pycnonotus jocosus is an Asian species which, following accidental introduction only 30 years ago, has colonized the two climatically and ecologically contrasting sides of the island of Réunion in the Indian Ocean. We assessed the degree of morphological divergence of mature birds in 11 non-seasonal and three seasonal characters, in windward and leeward sites. Our study showed (1) that sexual dimorphism existed, (2) that when sexual dimorphism is controlled, nine non-seasonal characters differed significantly between windward and leeward sites, (3) that these non-seasonal characters define groups of geographically proximal sites, especially in males, and (4) that classification according to the most indicative character, the bill, also clearly separated birds from windward and leeward sites. These results indicate very rapid morphological divergence, particularly in bill size, in an introduced bird species in fewer than ten generations. We suggest that differences in diet could partly explain this variability. 相似文献
77.
Phylogenetic position of the trichomonad parasite of turkeys, Histomonas meleagridis (Smith) Tyzzer, inferred from small subunit rRNA sequence. 总被引:1,自引:0,他引:1
DELPHINE GERBOD VIRGINIA P. EDGCOMB CHRISTOPHE NOËL LIONEL ZENNER REN WINTJENS PILAR DELGADO‐VISCOGLIOSI MICHAEL E. HOLDER MITCHELL L. SOGIN ERIC VISCOGLIOSI 《The Journal of eukaryotic microbiology》2001,48(4):498-504
The phylogenetic position of the trichomonad, Histomonas meleagridis was determined by analysis of small subunit rRNAs. Molecular trees including all identified parabasalid sequences available in data bases were inferred by distance, parsimony, and likelihood methods. All reveal a close relationship between H. meleagridis, and Dientamoeba fragilis. Moreover, small subunit rRNAs of both amoeboid species have a reduced G + C content and increased chain length relative to other parabasalids. Finally, the rRNA genes from H. meleagridis and D. fragilis share a recent common ancestor with Tritrichomonasfoetus, which exhibits a more developed cytoskeleton. This indicates that Histomonas and Dientamoeba secondarily lost most of the typical trichomonad cytoskeletal structures and hence, do not represent primitive morphologies. A global phylogeny of parabasalids revealed significant discrepancies with morphology-based classifications, such as the polyphyly of most of the parabasalid families and classes included in our study. 相似文献
78.
Egg cannibalism by hatchlings has been demonstrated in somepulmonate land snails; this behaviour is promoted by a highhatching asynchrony within the egg-batch. Under laboratory conditions,the percentage of new-born snails Helix aspersa having cannibalisedunhatched eggs was not influenced by the soil factor: about70% of them ingested one egg within their first four days oflife whether soil was present or not. The propensity to eggcannibalism in hatchlings of H. aspersa increased with egg density.However, most of the new-born hatchlings consumed a single eggduring the four days following hatching, and only exceptionallytwo. The consumption of one egg increased the snails wet weightby 38.7% within four days. A weak ingestion of soil componentsalso occurred, but it induced a growth that was three-timesless than that due to the consumption of an egg. In addition,the survival of newly hatched snails maintained under non-dehydratingthermohygrometric conditions was high, even when they were submittedto four days food-deprivation. (Received 22 July 1999; accepted 24 November 1999) 相似文献
79.
BLAKELEY STEPHEN D.; ROBAGLIA CHRISTOPHE; BRZEZINSKI RYSZARD; THIRION JEAN-PAUL 《Journal of experimental botany》1986,37(7):956-964
Blakeley, S. D., Robaglia, C, Brzezinski, R. and Thirion, J-P.1986. Induction oflow molecular weight cadmium-binding compoundin soybean roots.J. exp. Bot. 37: 956964. A Cd-binding compound has been identified in roots of Cd-treatedsoybean plants (Glycine max L.). Induction of synthesis of thiscompound after treatment with CdCl2 was monitored by labellingwith either 109Cd in vitro or with 35S-cysteine or 35S-methioninein vivo. The apparent molecular weight as determined by gelfiltration was about 14000 daltons. However, after carboxymethylationand electrophoresis under denaturing conditions its molecularweight was less than 3400 daltons. Simultaneous labelling with109 and 35S-cysteine demonstrated that the compound containscysteine residues. Gel electrophoresis of 35S-cysteine or 35S-methioninelabelled protein samples showed the compound to be rich in cysteinebut not in methionine, and that it was induced about 60-foldby 1?0 mol m3 CdCl2 after 7 d. Key words: Soybean, cadmium, induction, root 相似文献
80.
DANIELLE ROJAS-ROUSSE GERALDINE DOURY CHRISTOPHE TERRASSE ROBERT KALMES 《Physiological Entomology》1995,20(2):147-154
Abstract. The plasticity of the stinging behaviour of female Eupelmidae ( Eupelmus vuilleti Crawford, E. orientalis Crawford Hymenoptera: Eupelmidae) was analysed through the interrelationships of a parasitic community living on larval stage of Callosobruchus maculatus Fabricius (Coleoptera: Bruchidae). In traditional African grainstores, Eupelmus females have at their disposal all the larval stages of their host. Their exploitation is revealed by the sting observed on the host caused by the ovipositor of parasitoid females. This stinging behaviour begins immediately on the adult female's emergence, and thereafter there is a daily increase in the number of hosts stung. Stinging activity is linked to the age of the available hosts, but not all of the hosts available are exploited by the two species studied. This absence of total exploitation could indicate a threshold of activity in the stinging acts which could be in part linked to the secretion activity of the poison glands of parasitoid female.
In females of E. vuilleti and E.orientalis the stinging act is usually associated with egg-laying. The relationship between stinging and egg-laying is stronger in more advanced larval stages of the host.
In the presence of parasitized hosts, females of E. orientalis and E.vuilleti can exhibit hyperparasitism. The majority of larvae (i.e. primary parasitoid) that have been hyperparasitized have been stung and a large number of them are completely inactive. However, E. vuilleti females deposited their eggs in the available space of the pupation chamber of the host. The neonatal larvae from these scattered eggs could exploit any available host without the female having 'prepared the ground' at the time of egg-laying.
In Eupelmidae, all this happens as if there were a complementary action between the females and the neonate which could, if necessary, reinforce and/or compensate for the deficiencies in the host exploitation by the female. 相似文献
In females of E. vuilleti and E.orientalis the stinging act is usually associated with egg-laying. The relationship between stinging and egg-laying is stronger in more advanced larval stages of the host.
In the presence of parasitized hosts, females of E. orientalis and E.vuilleti can exhibit hyperparasitism. The majority of larvae (i.e. primary parasitoid) that have been hyperparasitized have been stung and a large number of them are completely inactive. However, E. vuilleti females deposited their eggs in the available space of the pupation chamber of the host. The neonatal larvae from these scattered eggs could exploit any available host without the female having 'prepared the ground' at the time of egg-laying.
In Eupelmidae, all this happens as if there were a complementary action between the females and the neonate which could, if necessary, reinforce and/or compensate for the deficiencies in the host exploitation by the female. 相似文献