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11.
Summary The content of fatty acids was analysed in an exudate from roots of pine seedlings grown axenically in vermiculite with a synthetic nutrient medium. The dominating fatty acdis were fewer in the exudate than in the roots. Unsaturated fatty acids were predominant. The total lipid fraction of the exudate promoted mycelial growth in two of the three ectomycorrhizal fungi tested. 相似文献
12.
Fang Chang An Yan Li-Na Zhao Wei-Hua Wu Zhenbiao Yang 《植物学报(英文版)》2007,49(8):1261-1270
A tip-focused Ca^2+ gradient is tightly coupled to polarized pollen tube growth, and tip-localized influxes of extracellular Ca^2+ are required for this process. However the molecular identity and regulation of the potential Ca^2+ channels remains elusive. The present study has implicated CNGC18 (cyclic nucleotide-gated channel 18) in polarized pollen tube growth, because its overexpression induced wider and shorter pollen tubes. Moreover, CNGC18 overexpression induced depolarization of pollen tube growth was suppressed by lower extracellular calcium ([Ca^2+]ex). CNGC18-yellow fluorescence protein (YFP) was preferentially localized to the apparent post-Golgi vesicles and the plasma membrane (PM) in the apex of pollen tubes. The PM localization was affected by tip-localized ROP1 signaling. Expression of wild type ROP1 or an active form of ROP1 enhanced CNGC18-YFP localization to the apical region of the PM, whereas expression of RopGAP1 (a ROP1 deactivator) blocked the PM localization. These results support a role for PM-Iocalized CNGC18 in the regulation of polarized pollen tube growth through its potential function in the modulation of calcium influxes. 相似文献
13.
Relative growth rate correlates negatively with pathogen resistance in radish: the role of plant chemistry 总被引:2,自引:0,他引:2
E. HOFFLAND G. J. NIEMANN J. A. VAN PELT J. B. M. PUREVEEN G. B. EIJKEL J. J. BOON H. LAMBERS 《Plant, cell & environment》1996,19(11):1281-1290
Plant growth rate has frequently been associated with herbivore defence: a large investment in quantitative defence compounds occurs at the expense of growth. We tested whether such a relationship also holds for growth rate and pathogen resistance. For 15 radish (Raphanus sativus L.) cultivars, we determined the potential growth rate and the resistance to fungal wilt disease caused by Fusarium oxysporum. We subsequently aimed to explain a putative negative relationship between growth rate and resistance based on plant chemical composition. Both growth rate and resistance level varied greatly among cultivars. Moreover, there was a strong negative correlation between growth rate and resistance, i.e. there are costs associated with a high resistance level. Roots of slow-growing, resistant cultivars have a higher biomass density. Using pyrolysis mass spectrometry. we part1y explained variation in both growth rate and resistance in terms of the same change in chemical composition. Leaves of slow-growing, resistant cultivars contained more cell wall material. Surprisingly, roots of slow-growing, highly resistant cultivars contained significantly less cell wall material, and more cytoplasmic elements (proteins). We speculate that this higher protein concentration is related to high construction and turn-over costs and high metabolic activity. The latter in turn is thought to be responsible for a rapid and adequate resistance reaction, in which phenols may be involved. 相似文献
14.
Morphological mutation of Lentinula edodes mycelium, particularly detectable in the dikaryotic state
A morphological mutation particularly detectable in the dikaryotic state was found in Lentinula edodes. The mutant dikaryon was readily distinguishable from the normal dikaryon by the irregularly branched short hyphae, very
slow hyphal growth, and sparse aerial hyphae. Genetic analysis revealed that expression of this mutation was controlled by
a single recessive gene, mor-13. Linkage analysis showed that the mor-13 was not linked to either the incompatibility factors (A and B) or the five kinds of mor genes that were segregated independently of each other in a previous study.
Contribution no. 380 from the Tottori Mycological Institute 相似文献
15.
Abstract. Soil resource availability may affect plant regeneration by resprouting in disturbed environments directly, by affecting plant growth rates, or indirectly by determining allocation to storage in the resprouting organs. Allocation to storage may be higher in stressful, low resource‐supply soils, but under such conditions plant growth rates may be lower. These factors could act in opposite directions leading to poorly known effects on resprouting. This paper analyses the role played by soil resources in the production and growth of resprouts after removal of above‐ground plant tissues in the Mediterranean shrub Erica australis. At 13 sites, differing in substrate, we cut the base of the stems of six plants of E. australis and allowed them to resprout and grow for two years. Soils were chemically analysed and plant water potential measured during the summer at all sites to characterize soil resource availability. We used stepwise regression analysis to determine the relationships between the resprouting response [mean site values of the number of resprouts (RN), maximum length (RML) and biomass (RB)] and soil nutrient content and plant water potential at each site. During the first two years of resprouting there were statistically significant differences among sites in the variables characterizing the resprouting response. RML was always different among sites and had little relationship with lignotuber area. RN was less different among sites and was always positively correlated with lignotuber area. RB was different among sites after the two years of growth. During the first months of resprouting, RN and RML were highly and positively related to the water status of the plant during summer. At later dates soil fertility variables came into play, explaining significant amounts of variance of the resprouting variables. Soil extractable cations content was the main variable accounting for RML and RB. Our results indicate that resprout growth of E. australis is positively affected by high water availability at the beginning of the resprouting response and negatively so by high soil extractable cation content at later periods. Some of these factors had previously shown to be related, with an opposite sign, to the development of a relatively larger lignotuber. Indeed, RML and RB measured in the second year of resprouting were significantly and negatively correlated with some indices of biomass allocation to the lignotuber at each site. This indicates that sites favouring allocation to the resprouting organ may not favour resprout growth. 相似文献
16.
《Animal : an international journal of animal bioscience》2007,1(7):1026-1032
Newborn rabbits depend on a daily nursing interaction with the mother to gain milk and to survive. During this interaction, they localise and seize the nipples displaying a typical behaviour triggered by maternal odour cues. The mammary pheromone constitutes such a signal in domestic rabbits: it elicits sucking-related movements in more than 90% of the pups. However, some newborns remain unresponsive to the presentation of the pheromone, even pups apparently healthy and highly motivated to suck. The main goal of the present study was therefore to explore the link between the unresponsiveness of rabbit pups to the mammary pheromone and their growth and survival in breeding conditions. To that end, 293 newborns from 30 litters were tested for their head searching-oral grasping responses to the mammary pheromone on days 1 and 3, and their milk intake and mortality were followed up from days 1 to 21. It was hypothesised that unresponsive newborns would have subsequent difficulties in finding nipples, sucking and surviving. Early weight and success in milk intake were further considered as mediating factors in growth and viability. The results showed that pups that were unresponsive to the mammary pheromone on day 1 were less successful in gaining milk and had a higher rate of mortality than the responsive pups. However, this impact was modulated by the weight of pups: it appeared only in the lightest newborns. Moreover, this impact vanished on day 3. On the other hand, the pup weight and sucking success on days 1 to 3 strongly influenced viability and growth during the period extending from days 1 to 21. Taken together, the results show that the day-1 responsiveness of rabbit pups to the mammary pheromone can be considered as an indicator of individual viability in pups having a small weight (<48 g on day 1). The predictive validity of the pups’ pheromonal reactivity seems however time-limited as it works only during the first, but crucial, postnatal days. 相似文献
17.
Effects of global environmental change on carbon partitioning in vegetative plants of Triticum aestivum and closely related Aegilops species 总被引:1,自引:0,他引:1
HANS LAMBERS RIKI VAN DEN BOOGAARD ERIK J. VENEKLAAS RAFAEL VILLAR 《Global Change Biology》1995,1(6):397-406
The use of fossil fuel is predicted to cause an increase of the atmospheric CO2 concentration, which will affect the global pattern of temperature and precipitation. It is therefore essential to incorporate effects of temperature and water supply on carbon partitioning of plants to predict effects of elevated [CO2] on growth and yield of Triticum aestivum. Although earlier papers have emphasized that elevated [CO2] favours investment of biomass in roots relative to that in leaves, it has now become clear that these are indirect effects, due to the more rapid depletion of nutrients in the root environment as a consequence of enhanced growth. Broadly generalized, the effect of temperature on biomass allocation in the vegetative stage is that the relative investment of biomass in roots is lowest at a certain optimum temperature and increases at both higher and lower temperatures. This is found not only when the temperature of the entire plant is varied, but also when only root temperature is changed whilst shoot temperature is kept constant. Effects of temperature on the allocation pattern can be explained largely by the effect of root temperature on the roots' capacity to transport water. Effects of a shortage in water supply on carbon partitioning are unambiguous: roots receive relatively more carbon. The pattern of biomass allocation in the vegetative stage and variation in water-use efficiency are prime factors determining a plant's potential for early growth and yield in different environments. In a comparison of a range of T. aestivum cultivars, a high water-use efficiency at the plant level correlates positively with a large investment in both leaf and root biomass, a low stomatal conductance and a large investment in photosynthetic capacity. We also present evidence that a lower investment of biomass in roots is not only associated with lower respiratory costs for root growth, but also with lower specific costs for ion uptake. We suggest the combination of a number of traits in future wheat cultivars, i.e. a high investment of biomass in leaves, which have a low stomatal conductance and a high photosynthetic capacity, and a low investment of biomass in roots, which have low respiratory costs. Such cultivars are considered highly appropriate in a future world, especially in the dryer regions. Although variation for the desired traits already exists among wheat cultivars, it is much larger among wild Aegilops species, which can readily be crossed with T. aestivum. Such wild relatives may be exploited to develop new wheat cultivars well-adapted to changed climatic conditions. 相似文献
18.
《Animal : an international journal of animal bioscience》2020,14(6):1120-1127
In order to map quantitative trait loci (QTLs) for allometries of body compositions and metabolic traits in chicken, we phenotypically characterize the allometric growths of multiple body components and metabolic traits relative to BWs using joint allometric scaling models and then establish random regression models (RRMs) to fit genetic effects of markers and minor polygenes derived from the pedigree on the allometric scalings. Prior to statistically inferring the QTLs for the allometric scalings by solving the RRMs, the LASSO technique is adopted to rapidly shrink most of marker genetic effects to zero. Computer simulation analysis confirms the reliability and adaptability of the so-called LASSO-RRM mapping method. In the F2 population constructed by multiple families, we formulate two joint allometric scaling models of body compositions and metabolic traits, in which six of nine body compositions are tested as significant, while six of eight metabolic traits are as significant. For body compositions, a total of 14 QTLs, of which 9 dominant, were detected to be associated with the allometric scalings of drumstick, fat, heart, shank, liver and spleen to BWs; while for metabolic traits, a total of 19 QTLs also including 9 dominant be responsible for the allometries of T4, IGFI, IGFII, GLC, INS, IGR to BWs. The detectable QTLs or highly linked markers can be used to regulate relative growths of the body components and metabolic traits to BWs in marker-assisted breeding of chickens. 相似文献
19.
Cheka Kehelpannala Thusitha Rupasinghe Asher Pasha Eddi Esteban Thomas Hennessy David Bradley Berit Ebert Nicholas J. Provart Ute Roessner 《The Plant journal : for cell and molecular biology》2021,107(1):287-302
Mass spectrometry is the predominant analytical tool used in the field of plant lipidomics. However, there are many challenges associated with the mass spectrometric detection and identification of lipids because of the highly complex nature of plant lipids. Studies into lipid biosynthetic pathways, gene functions in lipid metabolism, lipid changes during plant growth and development, and the holistic examination of the role of plant lipids in environmental stress responses are often hindered. Here, we leveraged a robust pipeline that we previously established to extract and analyze lipid profiles of different tissues and developmental stages from the model plant Arabidopsis thaliana. We analyzed seven tissues at several different developmental stages and identified more than 200 lipids from each tissue analyzed. The data were used to create a web-accessible in silico lipid map that has been integrated into an electronic Fluorescent Pictograph (eFP) browser. This in silico library of Arabidopsis lipids allows the visualization and exploration of the distribution and changes of lipid levels across selected developmental stages. Furthermore, it provides information on the characteristic fragments of lipids and adducts observed in the mass spectrometer and their retention times, which can be used for lipid identification. The Arabidopsis tissue lipid map can be accessed at http://bar.utoronto.ca/efp_arabidopsis_lipid/cgi-bin/efpWeb.cgi . 相似文献
20.
Location within a tree was analyzed as a source of variation in Sequoia sempervirens leaf monoterpenes. No differences were found for quantitative composition or total yield/dry wt among lower, middle and upper canopy positions. The awlshaped, spirally arranged leaves of vigorous upper shoots showed small quantitative compositional differences, but not differences in total yield. The intermediate leaf form of young sprouts had the most different monoterpene quantitative composition and about three times the total yield of the above two leaf forms. Analysis of a clonal ring of 17 adult trees resulted in coefficients of variation similar to those for samples collected from different canopy levels of the same shoot. Results revealed the sources and magnitudes of experimental error in comparative studies of this species' leaf monoterpenes, and did not support the concept that somatic mutation provides an important source of variation in a large, long-lived organism such as coast redwood. 相似文献