植物器官的大小调控是一个重要的生物学过程,直接影响农作物产量。目前对于植物器官大小调控的研究集中在转录调控、激素信号通路及蛋白质合成与修饰等多个水平和途径,但具体的分子机制并不是很清晰。李云海实验室前期研究发现了一个器...植物器官的大小调控是一个重要的生物学过程,直接影响农作物产量。目前对于植物器官大小调控的研究集中在转录调控、激素信号通路及蛋白质合成与修饰等多个水平和途径,但具体的分子机制并不是很清晰。李云海实验室前期研究发现了一个器官大小的关键调控基因UBIQUITIN SPECIFIC PROTEASE 15(UBP15)/SUPPRESSOR2 OF DA1(SOD2)。sod2-1突变体由于UBP15基因缺失导致器官变小。UBP15作为DA1的底物,其蛋白稳定性受DA1的调节,但其下游通路并不清楚。为了进一步了解UBP15调控器官大小的分子机制,通过EMS诱变筛选分离得到了sod2-1的抑制突变体sus40-1D。sus40-1D sod2-1突变体与sod2-1植株相比,子叶、花瓣和种子面积显著增大。遗传分析表明sus40-1D为显性突变。基因组重测序及连锁分析鉴定出2个与sus40-1D紧密连锁的候选基因:At1g05820和At1g08470。At1g05820的突变发生在内含子区域,而At1g08470的突变发生在外显子区。本研究发现了一个调控器官大小的突变体sus40-1D,对该突变体的进一步研究将有助于解析植物器官大小的调控机制。展开更多
We propose a bio-optical inversion model that retrieves the absorption contributions of phytoplankton and colored detrital matter(CDM),as well as the phytoplankton size classes(PSCs),from total minus water absorption ...We propose a bio-optical inversion model that retrieves the absorption contributions of phytoplankton and colored detrital matter(CDM),as well as the phytoplankton size classes(PSCs),from total minus water absorption spectra.The model is based on three-component separation of phytoplankton size structure and a genetic algorithm.The model performance was tested on two independent datasets(the NASA bio-Optical Marine Algorithm Dataset(NOMAD) and the northern South China Sea(NSCS) dataset).The relationships between the estimated and measured values were strongly linear,especially for aCDM(412),and the Root Mean Square Error(RMSE) of the CDM exponential slope(SCDM) was relatively low.Next,the inversion model was directly applied to in-situ total minus water absorption spectra determined by an underwater meter during a cruise in September 2008,to retrieve the phytoplankton size structure in the seawater.By comparing the measured and retrieved chlorophyll a concentrations,we demonstrated that total and size-specific chlorophyll a concentrations could be retrieved by the model with relatively high accuracy.Finally,we applied the bio-optical inversion model to investigate changes in phytoplankton size structure induced by an anti-cyclonic eddy in the NSCS.展开更多
Investigation was carried out on the significance of seed size on morphological traits in seedlings of Buchholzia eoriaeea Engler, a medicinal plant in Southwestern Nigeria. Three size classes-large （seeds 〉 40 g）,...Investigation was carried out on the significance of seed size on morphological traits in seedlings of Buchholzia eoriaeea Engler, a medicinal plant in Southwestern Nigeria. Three size classes-large （seeds 〉 40 g）, medium （seeds between 25 and 40 g） and small （seed 〈 25 g） were used. Ninety uniformly growing seedlings from each size class were assessed for shoot height, number of leaves, collar diameter, leaf area and biomass production for six months. Seed size showed significant effect on height growth, collar diameter and number of leaves （P 〈 0.05）. Seedlings from large seed size class had the best height and collar diameter （45.3 cm, 8.7 mm）. Seeds of large and medium seed size classes had overall means of 15.6 and 15.5 leaves/seedling respectively. Leaf dry weight, stem dry weight and root biomass in seedlings from the three seed size classes were significantly different at P 〈 0.05 with the highest mean values for leaf dry weight, stem dry weight and root biomass recorded by seedlings from the large seed size class. The results showed that seed size has great influence on seedling growth when they are young. With availability of sufficient nutrient and light, effect of seed size on seedling growth and development could disappear as seedlings attain maturity.展开更多
The effects of two culture systems, conventional and no-till combined the previous crop （lentil and wheat） on soil properties were studied in the experimental site of the station Technical Institute for Field Crops ...The effects of two culture systems, conventional and no-till combined the previous crop （lentil and wheat） on soil properties were studied in the experimental site of the station Technical Institute for Field Crops （ITGC） Setif （Algeria） during the crop year 2011/2012. The results indicate that the no-till system affects positively the variables of soil properties and the organic matter has a rate of 2.89% compared to 2.44% in conventional tillage. If the conventional system has an infiltration of moisture relatively higher than that observed for no-till throughout the cycle, the no-tillage is distinguished by a higher storage of moisture at the end of cycle wheat cultivation. The results also indicate that the density （1.44 g/cm）, permeability （22.79 cm/h） and soil compaction （12.51 kg/cm） in no-till were significantly higher compared to conventional tillage 1.35 g/cm, 14.13 cm/h, 7.40 kg/cm, respectively.展开更多
Chlordecone, one of the most persistent organochlorine pesticides, was applied between 1972 and 1993 in banana fields in the French West Indies, which results in long-term pollution of soils and contamination of water...Chlordecone, one of the most persistent organochlorine pesticides, was applied between 1972 and 1993 in banana fields in the French West Indies, which results in long-term pollution of soils and contamination of waters, aquatic biota, and crops. As human exposure to chlordecone is mainly due to food contamination, early research was focused on chlordecone transfer to crops. Field trials were conducted to investigate chlordecone contamination of yam, sweet potato, turnip, and radish grown on a Ferralic Nitisol polluted by chlordecone. We also carried out trials on yam, courgette, and tomato under greenhouse conditions with homogenized Andosol and Nitisol, polluted by chlordecone to various extents. Our results indicated that i) all tubers were contaminated in accordance with the chlordecone content of the soils; ii) the plant contamination capacity of the Nitisol was greater than that of the Andosol; and iii) whatever the soil type, tuber contamination was related to the soil volumetric content of dissolved chlordecone. Nevertheless, no tubers showed sufficient chlordecone uptake for efficient soil decontamination by means of plant extraction. Soil contact accounted for most of the root crop contamination, which was inversely proportional to the tuber size. Internal transfer might also increase root crop contamination when the root central cylinder contained raw sap flow, as in the case of turnip or radish. Courgette fruits showed high contamination without soil contact. Thus, further research is needed to explore the pattern of both below- and aboveground plant chlordecone contamination and assess the hypothesis of its correlation with sap flow. Finally, we used our results to build a decisionmaking tool for farmers, relating soil pollution with the maximal contamination of the harvested organs to predict crop contamination and thus assisting farmers in making crop choices at planting in order to conform with the European Union's regulations.展开更多
Polyploidization via whole-genome duplications （WGD） is a common phenomenon in organisms. However, investigations into this phenomenon differ greatly between plants and animals. Recent research on polyploid plants i...Polyploidization via whole-genome duplications （WGD） is a common phenomenon in organisms. However, investigations into this phenomenon differ greatly between plants and animals. Recent research on polyploid plants illustrates the immediate changes that follow WGDs and the mechanisms behind in both genetic and epigenetic consequences. Unfortunately, equivalent questions remain to be explored in animals. Enlightened by botanical research, the study of polyploidization in vertebrates involves the identification of model animals and the establishment of strategies. Here we review and compare the research on plants and vertebrates while considering intrageneric or intraspecific variation in genome size. Suitable research methods on recently established poly- ploidy systems could provide important clues for under- standing what happens after WGDs in vertebrates. The approach yields insights into survival and the rarity of polyploidization in vertebrates. The species of Carassius and the allopolyploid system of goldfish × common carp hybridization appear to be suitable models for unraveling the evolution and adaptation of polyploid vertebrates.展开更多
Forest edges have been well studied in temperate and tropical forests,but less so in open canopy forests.We investigated edge influence on plant species diversity and soil properties in sparse oak forest fragments.Dat...Forest edges have been well studied in temperate and tropical forests,but less so in open canopy forests.We investigated edge influence on plant species diversity and soil properties in sparse oak forest fragments.Data were collected along three transects from the edge to the interior of three small(under 10 ha)and three large(over 10 ha)oak forest fragments in Kermanshah Province,Iran.We measured herbaceous plants(<0.5 m in height)and soil attributes at 0(forest edge),25,50,100 and 150 m.We quantified species diversity using the Shannon index,used rarefaction to compare species richness between two different sizes of fragments and applied non-metric multidimensional scaling ordination to investigate the variation in species composition.We estimated the distance of edge influence using randomization tests.Generalized linear mixed models with post-hoc Tukey’s HSD tests were used to assess the effects of distance from edge and fragment size on diversity and soil properties.We found greater species richness,diversity and evenness at the edge of both small and large fragments and lower nitrogen and organic carbon at the edge compared to the interior of large fragments,with most changes within 50 m of the edge.Species composition,organic carbon and total nitrogen were significantly different between small and large fragments.Our findings of significant edge influence on herbaceous plants and soil properties in these sparse forests provide a significant contribution to the literature on edges,especially in relation to herbaceous plants.展开更多
基金supported by Research Fund of the Doctoral Program of Higher Education(200805720004)Scientific Research Foundation for Returned Scholars,Ministry of Education of China([2009]1001)
文摘植物器官的大小调控是一个重要的生物学过程,直接影响农作物产量。目前对于植物器官大小调控的研究集中在转录调控、激素信号通路及蛋白质合成与修饰等多个水平和途径,但具体的分子机制并不是很清晰。李云海实验室前期研究发现了一个器官大小的关键调控基因UBIQUITIN SPECIFIC PROTEASE 15(UBP15)/SUPPRESSOR2 OF DA1(SOD2)。sod2-1突变体由于UBP15基因缺失导致器官变小。UBP15作为DA1的底物,其蛋白稳定性受DA1的调节,但其下游通路并不清楚。为了进一步了解UBP15调控器官大小的分子机制,通过EMS诱变筛选分离得到了sod2-1的抑制突变体sus40-1D。sus40-1D sod2-1突变体与sod2-1植株相比,子叶、花瓣和种子面积显著增大。遗传分析表明sus40-1D为显性突变。基因组重测序及连锁分析鉴定出2个与sus40-1D紧密连锁的候选基因:At1g05820和At1g08470。At1g05820的突变发生在内含子区域,而At1g08470的突变发生在外显子区。本研究发现了一个调控器官大小的突变体sus40-1D,对该突变体的进一步研究将有助于解析植物器官大小的调控机制。
基金Supported by the Key Projects of the National Natural Science Foundation of China(Nos.41076014,U0933005,41176035,40906022,41206029)
文摘We propose a bio-optical inversion model that retrieves the absorption contributions of phytoplankton and colored detrital matter(CDM),as well as the phytoplankton size classes(PSCs),from total minus water absorption spectra.The model is based on three-component separation of phytoplankton size structure and a genetic algorithm.The model performance was tested on two independent datasets(the NASA bio-Optical Marine Algorithm Dataset(NOMAD) and the northern South China Sea(NSCS) dataset).The relationships between the estimated and measured values were strongly linear,especially for aCDM(412),and the Root Mean Square Error(RMSE) of the CDM exponential slope(SCDM) was relatively low.Next,the inversion model was directly applied to in-situ total minus water absorption spectra determined by an underwater meter during a cruise in September 2008,to retrieve the phytoplankton size structure in the seawater.By comparing the measured and retrieved chlorophyll a concentrations,we demonstrated that total and size-specific chlorophyll a concentrations could be retrieved by the model with relatively high accuracy.Finally,we applied the bio-optical inversion model to investigate changes in phytoplankton size structure induced by an anti-cyclonic eddy in the NSCS.
文摘Investigation was carried out on the significance of seed size on morphological traits in seedlings of Buchholzia eoriaeea Engler, a medicinal plant in Southwestern Nigeria. Three size classes-large （seeds 〉 40 g）, medium （seeds between 25 and 40 g） and small （seed 〈 25 g） were used. Ninety uniformly growing seedlings from each size class were assessed for shoot height, number of leaves, collar diameter, leaf area and biomass production for six months. Seed size showed significant effect on height growth, collar diameter and number of leaves （P 〈 0.05）. Seedlings from large seed size class had the best height and collar diameter （45.3 cm, 8.7 mm）. Seeds of large and medium seed size classes had overall means of 15.6 and 15.5 leaves/seedling respectively. Leaf dry weight, stem dry weight and root biomass in seedlings from the three seed size classes were significantly different at P 〈 0.05 with the highest mean values for leaf dry weight, stem dry weight and root biomass recorded by seedlings from the large seed size class. The results showed that seed size has great influence on seedling growth when they are young. With availability of sufficient nutrient and light, effect of seed size on seedling growth and development could disappear as seedlings attain maturity.
文摘The effects of two culture systems, conventional and no-till combined the previous crop （lentil and wheat） on soil properties were studied in the experimental site of the station Technical Institute for Field Crops （ITGC） Setif （Algeria） during the crop year 2011/2012. The results indicate that the no-till system affects positively the variables of soil properties and the organic matter has a rate of 2.89% compared to 2.44% in conventional tillage. If the conventional system has an infiltration of moisture relatively higher than that observed for no-till throughout the cycle, the no-tillage is distinguished by a higher storage of moisture at the end of cycle wheat cultivation. The results also indicate that the density （1.44 g/cm）, permeability （22.79 cm/h） and soil compaction （12.51 kg/cm） in no-till were significantly higher compared to conventional tillage 1.35 g/cm, 14.13 cm/h, 7.40 kg/cm, respectively.
基金Supported by the Ministry of Ecology and Sustainable Development and the Ministry of Agriculture and Food,France,the French National Agency of Research,and the French National Chlordecone Action Plan
文摘Chlordecone, one of the most persistent organochlorine pesticides, was applied between 1972 and 1993 in banana fields in the French West Indies, which results in long-term pollution of soils and contamination of waters, aquatic biota, and crops. As human exposure to chlordecone is mainly due to food contamination, early research was focused on chlordecone transfer to crops. Field trials were conducted to investigate chlordecone contamination of yam, sweet potato, turnip, and radish grown on a Ferralic Nitisol polluted by chlordecone. We also carried out trials on yam, courgette, and tomato under greenhouse conditions with homogenized Andosol and Nitisol, polluted by chlordecone to various extents. Our results indicated that i) all tubers were contaminated in accordance with the chlordecone content of the soils; ii) the plant contamination capacity of the Nitisol was greater than that of the Andosol; and iii) whatever the soil type, tuber contamination was related to the soil volumetric content of dissolved chlordecone. Nevertheless, no tubers showed sufficient chlordecone uptake for efficient soil decontamination by means of plant extraction. Soil contact accounted for most of the root crop contamination, which was inversely proportional to the tuber size. Internal transfer might also increase root crop contamination when the root central cylinder contained raw sap flow, as in the case of turnip or radish. Courgette fruits showed high contamination without soil contact. Thus, further research is needed to explore the pattern of both below- and aboveground plant chlordecone contamination and assess the hypothesis of its correlation with sap flow. Finally, we used our results to build a decisionmaking tool for farmers, relating soil pollution with the maximal contamination of the harvested organs to predict crop contamination and thus assisting farmers in making crop choices at planting in order to conform with the European Union's regulations.
基金supported by the National Natural Science Foundation of China(91331105,31360514)
文摘Polyploidization via whole-genome duplications （WGD） is a common phenomenon in organisms. However, investigations into this phenomenon differ greatly between plants and animals. Recent research on polyploid plants illustrates the immediate changes that follow WGDs and the mechanisms behind in both genetic and epigenetic consequences. Unfortunately, equivalent questions remain to be explored in animals. Enlightened by botanical research, the study of polyploidization in vertebrates involves the identification of model animals and the establishment of strategies. Here we review and compare the research on plants and vertebrates while considering intrageneric or intraspecific variation in genome size. Suitable research methods on recently established poly- ploidy systems could provide important clues for under- standing what happens after WGDs in vertebrates. The approach yields insights into survival and the rarity of polyploidization in vertebrates. The species of Carassius and the allopolyploid system of goldfish × common carp hybridization appear to be suitable models for unraveling the evolution and adaptation of polyploid vertebrates.
基金financially supported by the vice chancellor for research and technology of Urmia University and received no external funding.
文摘Forest edges have been well studied in temperate and tropical forests,but less so in open canopy forests.We investigated edge influence on plant species diversity and soil properties in sparse oak forest fragments.Data were collected along three transects from the edge to the interior of three small(under 10 ha)and three large(over 10 ha)oak forest fragments in Kermanshah Province,Iran.We measured herbaceous plants(<0.5 m in height)and soil attributes at 0(forest edge),25,50,100 and 150 m.We quantified species diversity using the Shannon index,used rarefaction to compare species richness between two different sizes of fragments and applied non-metric multidimensional scaling ordination to investigate the variation in species composition.We estimated the distance of edge influence using randomization tests.Generalized linear mixed models with post-hoc Tukey’s HSD tests were used to assess the effects of distance from edge and fragment size on diversity and soil properties.We found greater species richness,diversity and evenness at the edge of both small and large fragments and lower nitrogen and organic carbon at the edge compared to the interior of large fragments,with most changes within 50 m of the edge.Species composition,organic carbon and total nitrogen were significantly different between small and large fragments.Our findings of significant edge influence on herbaceous plants and soil properties in these sparse forests provide a significant contribution to the literature on edges,especially in relation to herbaceous plants.
