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181.

Background  

Plants trigger and tailor defense responses after perception of the oral secretions (OS) of attacking specialist lepidopteran larvae. Fatty acid-amino acid conjugates (FACs) in the OS of the Manduca sexta larvae are necessary and sufficient to elicit the herbivory-specific responses in Nicotiana attenuata, an annual wild tobacco species. How FACs are perceived and activate signal transduction mechanisms is unknown.  相似文献   
182.
The present study sought to determine which of the common Poaceae species in the study area contribute most to the Poaceae pollen season curve, and to determine the phenological behaviour of the species studied. The different floral phenophases in thirty-three Poaceae species common in and around the city of Córdoba (SW Iberian Peninsula) were checked periodically over the period 2004–2006. Results showed that longer phenological ranges were recorded in the coolest and wettest year, and shorter ranges in the warmest and driest year. Moreover, ranges varied as a function of altitude: populations in lower-lying areas flowered earlier than those at higher altitudes. The results, taken in conjunction with the findings of preliminary research into potential pollen production, showed that probably only four of the Poaceae species studied—Dactylis glomerata, Lolium rigidum, Trisetaria panicea and Vulpia geniculata—were major contributors to the Poaceae airborne pollen curve.  相似文献   
183.

Background  

The extended light-harvesting complex (LHC) protein superfamily is a centerpiece of eukaryotic photosynthesis, comprising the LHC family and several families involved in photoprotection, like the LHC-like and the photosystem II subunit S (PSBS). The evolution of this complex superfamily has long remained elusive, partially due to previously missing families.  相似文献   
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A male sterile line was isolated in marigold (Tagetes erecta L.) and cytological analysis determined this to be a novel genic male sterility trait (Tems). Through the use of amplified fragment length polymorphisms (AFLPs) and bulked segregant analysis (BSA), tightly linked markers of Tems were identified with a view towards a map-based cloning strategy. It was found that spontaneous homeotic conversion of floral organs was the underlying cause of the male sterility in this marigold line. Thus, petals of male sterile plants resembled sepal-like structures and the stamens were partially converted to styles, although without the full characteristics or function of the true style organs. We have constructed a fine marker-based map for the Tems gene. This is intended to provide a tool for marker assisted selection (MAS) strategies in hybrid breeding and map-based cloning strategies for the male sterility locus. We discuss the significance of this spontaneously derived genic male sterility trait relating to the homeotic conversion of floral organs in marigold.  相似文献   
187.
The role of CCN proteins in vivo is only just becoming understood. A prototypical member of the CCN family, CCN3 suppresses proliferation. In a study in press, Shimoyama and colleagues show that mice lacking CCN3 have a hyperproliferative response to vascular injury. These data, along with other recent observations, suggest that CCN3 may represent a novel therapy for hyperproliferative diseases.  相似文献   
188.
The use of the potent antitumor antibiotic doxorubicin (DOX) is hampered because of its severe cardiac toxicity that leads to the development of cardiomyopathy and heart failure. In this study, we have developed a cell culture model for DOX-induced myocardial injury using primary adult rat cardiomyocytes that were cultured in serum-free medium and exposed to 1 to 40 microM DOX. DOX caused a dose-dependent release of sarcosolic enzyme lactate dehydrogenase (LDH) from cultured myocytes. The release of LDH was prevented by the cell-permeable superoxide dismutase (SOD) mimetic (MnTBAP), but was unaffected by either cell-impermeable SOD enzyme, or manganese (II) sulfate. Ebselen, a glutathione peroxidase (GPx) mimetic, enhanced the protection of cardiomyocytes afforded by MnTBAP. DOX caused the increased formation of oxidants in cardiomyocytes, and MnTBAP lowered the amount of intracellular oxidants induced by DOX. In addition, DOX selectively inactivated aconitase in cardiomyocytes, and MnTBAP partially reversed this inactivation. Ebselen further amplified the protective effect of MnTBAP on aconitase activity. These results suggest that the SOD mimetic MnTBAP prevents DOX-induced damage to cardiomyocytes and that the GPx mimetic ebselen synergistically enhanced the cardioprotection afforded by MnTBAP. Relevance of these findings to minimizing cardiotoxicity in cancer treatment is discussed.  相似文献   
189.
In this paper we propose that the internal bracketing of a word with more than two morphemes is reflected in the phonetic implementation. We hypothesize that embedded forms show more phonetic reduction than forms at higher structural levels (‘Embedded Reduction Hypothesis’). This paper tests the prediction of the Embedded Reduction Hypothesis with triconstituent compounds. The analysis of the durational properties of almost 500 compound tokens shows that there is a lengthening effect on the non-embedded constituent, and a shortening effect on the adjacent embedded constituent. Yet, this predicted effect of embedding interacts with other lexical factors, above all the bigram frequency of the embedded compound. At a theoretical level, these effects mean that the durational properties of the cross-boundary constituents are indicative of the hierarchical structure and of the strength of the internal boundary of triconstituent compounds. Hence, morphological structure is reflected in the speech signal.  相似文献   
190.
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