The effects of four kinds of plant growth regulators with different concentrations on narcissi were studied in 2001. The results showed that the regulators could inhibit the growths of height and leaves of narcissi. O...The effects of four kinds of plant growth regulators with different concentrations on narcissi were studied in 2001. The results showed that the regulators could inhibit the growths of height and leaves of narcissi. Of the four regulators, the dwarfing effects of paclobatrazol (PP333) and uniconazole (S3307) on narcissi were better than those of chlorocholine (CCC) and dimethyl amino-sussinamic acid (B9). All of the regulators did not have significant effect on the root length. Moreover, the time of flowering was later for the narcissi treated with regulators than that of the control to a certain extent, and the range delayed was from 2 days to 19 days. The correlation analysis results showed that there was a significant correlation between the time of flowering and the concentrations of regulators. The ornament value of narcissi was obviously improved by using the regulators.展开更多
By solution culture experiment, three wheat genotypes (Ttiticum aestivum L.) and two oilseed rape genotypes (Brassica napus L.) differing in Mn efficiency under Mn-deficient conditions were used to study mechanisms of...By solution culture experiment, three wheat genotypes (Ttiticum aestivum L.) and two oilseed rape genotypes (Brassica napus L.) differing in Mn efficiency under Mn-deficient conditions were used to study mechanisms of the difference in Mn efficiency between wheat and oilseed rape. The results showed that there were significant differences in the abilities of MnIV reduction and acidification in root rhizosphere between the two species. Compared with wheat, oilseed rape had much higher reducing capacity and intensity of rhizosphere acidification under Mn-deficient conditions. Moreover, the higher ratio of functional leaves Mn/old leaves Mn in oilseed rape than in wheat was also an important factor for the different Mn efficiencies between the two species.展开更多
Algal blooms caused by eutrophication in fresh water are one of the major environmental problems in the world. Using biological methods to control algal growth, especially based on allelopathic inhibitory effects of a...Algal blooms caused by eutrophication in fresh water are one of the major environmental problems in the world. Using biological methods to control algal growth, especially based on allelopathic inhibitory effects of aquatic macrophytes on phytoplankton growth, have been received world-wide attention. In this study, the allelopathic activity of the invasive macrophyte, Eichhornia crassipes （water hyacinth）, on blue-green algae, Microcystis aeruginosa （PCC7806） was investigated using coexistence assay. Our results showed that water hyacinth had disparate effects on the growth ofM~ aeruginosa （PCC7806） under different initial algal densities. Under lower initial algal density （OD650 = 0.10 and OD650 = 0.05）, the algal growth was significantly inhibited by water hyacinth （inhibition ratio was 95.6% and 97.3%, respectively）. While it was stimulated at higher initial algal densities （OD650 = 0.20）. Water hyacinth inhibited the growth of algae mainly through its root system. Culture water from water hyacinth and aqueous methanol extracts from dry roots samples also showed inhibition effects on algal growth. The inhibition effects increased as the increase of crude extract concentration, suggest that water hyacinth may excrete inhibitory substances from root system and show allelopathic inhibitory potential to the growth ofM. aeruginosa.展开更多
Dark septate endophytic （DSE） fungi are ubiquitous and cosmopolitan, and occur widely in association with plants in heavy metal stress environment. However, little is known about the effect of inoculation with DSE f...Dark septate endophytic （DSE） fungi are ubiquitous and cosmopolitan, and occur widely in association with plants in heavy metal stress environment. However, little is known about the effect of inoculation with DSE fungi on the host plant under heavy metal stress. In this study, Gaeumannomyces cylindrosporus, which was isolated from Pb-Zn mine railings in China and had been proven to have high Pb tolerance, was inoculated onto the roots of maize （Zea mays L.） seedlings to study the effect of DSE on plant growth, photosynthesis, and the translocation and accumulation of Pb in plant under stress of different Pb concentrations. The growth indicators （height, basal diameter, root length, and biomass） of maize were detected. Chlorophyll content, photosynthetic characteristics （net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO2 concentration）, and chlorophyll fluorescence parameters in leaves of the inoculated and non-inoculated maize were also determined. Inoculation with G. cylindrosporus significantly increased height, basal diameter, root length, and biomass of maize seedlings under Pb stress. Colonization of G. cylindrosporus improved the efficiency of photosynthesis and altered the translocation and accumulation of Pb in the plants. Although inoculation with G. cylindrosporus increased Pb accumulation in host plants in comparison to non-inoculated plants, the translocation factor of Pb in plant body was significantly decreased. The results indicated that Pb was accumulated mainly in the root system of maize and the phytotoxicity of Pb to the aerial part of the plant was alleviated. The improvement of efficiency of photosynthesis and the decrease of translocation factor of Pb, caused by DSE fungal colonization, were efficient strategies to improve Pb tolerance of host plants.展开更多
Leucine rich repeat(LRR)domain,characterized by a repetitive sequence pattern rich in leucine residues,is a universal protein-protein interaction motif present in all life forms.LRR repeats interrupted by sequences of...Leucine rich repeat(LRR)domain,characterized by a repetitive sequence pattern rich in leucine residues,is a universal protein-protein interaction motif present in all life forms.LRR repeats interrupted by sequences of 30 70 residues(termed island domain,ID)have been found in some plant LRR receptor-like kinases(RLKs)and animal Toll-like receptors(TLR7-9).Recent studies provide insight into how a single ID is structurally integrated into an LRR protein.However,structural information on an LRR protein with two IDs is lacking.The receptor-like protein kinase 2(RPK2)is an LRR-RLK and has important roles in controlling plant growth and development by perception and transduction of hormone signal.Here we present the crystal structure of the extracellular LRR domain of RPK2(RPK2-LRR)containing two IDs from Arabidopsis.The structure reveals that both of the IDs are helical and located at the central region of the single RPK2-LRR solenoid.One of them binds to the inner surface of the solenoid,whereas the other one mainly interacts with the lateral side.Unexpectedly,a long loop immediately following the N-terminal capping domain of RPK2-LRR is presented toward and sandwiched between the two IDs,further stabilizing their embedding to the LRR solenoid.A potential ligand binding site formed by the two IDs and the solenoid is located at the C-terminal side of RPK2-LRR.The structural information of RPK2-LRR broadens our understanding toward the large family of LRR proteins and provides insight into RPK2-mediated signaling.展开更多
Soil biotic communities can strongly impact plant performance.In this paper,we ask the question:how longlasting the effect of the soil microbial community on plant growth is.We examined the plant growth rates at three...Soil biotic communities can strongly impact plant performance.In this paper,we ask the question:how longlasting the effect of the soil microbial community on plant growth is.We examined the plant growth rates at three stages:early,mid and late growth.We performed two growth experiments with Jacobaea vulgaris,which lasted 49 and 63 days in sterilized soil or live soil.In a third experiment,we examined the effect of the timing of soil inoculation prior to planting on the relative growth rate of J.vulgaris with four different timing treatments.In all experiments,differences in biomass of plants grown in sterilized soil and live soil increased throughout the experiment.Also,the relative growth rate of plants in the sterilized soil was only significantly higher than that of plants in the live soil in the first two to three weeks.In the third experiment,plant biomass decreased with increasing time between inoculation and planting.Overall,our results showed that plants of J.vulgaris grew less well in live soil than in sterilized soil.The negative effects of soil inoculation on plant mass appeared to extend over the whole growth period but arise from the negative effects on relative growth rates that occurred in the first weeks.展开更多
文摘The effects of four kinds of plant growth regulators with different concentrations on narcissi were studied in 2001. The results showed that the regulators could inhibit the growths of height and leaves of narcissi. Of the four regulators, the dwarfing effects of paclobatrazol (PP333) and uniconazole (S3307) on narcissi were better than those of chlorocholine (CCC) and dimethyl amino-sussinamic acid (B9). All of the regulators did not have significant effect on the root length. Moreover, the time of flowering was later for the narcissi treated with regulators than that of the control to a certain extent, and the range delayed was from 2 days to 19 days. The correlation analysis results showed that there was a significant correlation between the time of flowering and the concentrations of regulators. The ornament value of narcissi was obviously improved by using the regulators.
基金Project (No. 39425013) supported by the National Natural Science Foundation of China.
文摘By solution culture experiment, three wheat genotypes (Ttiticum aestivum L.) and two oilseed rape genotypes (Brassica napus L.) differing in Mn efficiency under Mn-deficient conditions were used to study mechanisms of the difference in Mn efficiency between wheat and oilseed rape. The results showed that there were significant differences in the abilities of MnIV reduction and acidification in root rhizosphere between the two species. Compared with wheat, oilseed rape had much higher reducing capacity and intensity of rhizosphere acidification under Mn-deficient conditions. Moreover, the higher ratio of functional leaves Mn/old leaves Mn in oilseed rape than in wheat was also an important factor for the different Mn efficiencies between the two species.
文摘Algal blooms caused by eutrophication in fresh water are one of the major environmental problems in the world. Using biological methods to control algal growth, especially based on allelopathic inhibitory effects of aquatic macrophytes on phytoplankton growth, have been received world-wide attention. In this study, the allelopathic activity of the invasive macrophyte, Eichhornia crassipes （water hyacinth）, on blue-green algae, Microcystis aeruginosa （PCC7806） was investigated using coexistence assay. Our results showed that water hyacinth had disparate effects on the growth ofM~ aeruginosa （PCC7806） under different initial algal densities. Under lower initial algal density （OD650 = 0.10 and OD650 = 0.05）, the algal growth was significantly inhibited by water hyacinth （inhibition ratio was 95.6% and 97.3%, respectively）. While it was stimulated at higher initial algal densities （OD650 = 0.20）. Water hyacinth inhibited the growth of algae mainly through its root system. Culture water from water hyacinth and aqueous methanol extracts from dry roots samples also showed inhibition effects on algal growth. The inhibition effects increased as the increase of crude extract concentration, suggest that water hyacinth may excrete inhibitory substances from root system and show allelopathic inhibitory potential to the growth ofM. aeruginosa.
基金supported by the National Natural Science Foundation of China (Nos. 41671268, 31270639, and 31400435)the Program for Changjiang Scholars and Innovative Research Team in University of China (No. IRT1035)+1 种基金the Hubei Provincial Natural Science Foundation of China (No. 2015CFB596)the Shaanxi Provincial Science and Technology Innovation Project Plan of China (No. 2016KTCL02-07)
文摘Dark septate endophytic （DSE） fungi are ubiquitous and cosmopolitan, and occur widely in association with plants in heavy metal stress environment. However, little is known about the effect of inoculation with DSE fungi on the host plant under heavy metal stress. In this study, Gaeumannomyces cylindrosporus, which was isolated from Pb-Zn mine railings in China and had been proven to have high Pb tolerance, was inoculated onto the roots of maize （Zea mays L.） seedlings to study the effect of DSE on plant growth, photosynthesis, and the translocation and accumulation of Pb in plant under stress of different Pb concentrations. The growth indicators （height, basal diameter, root length, and biomass） of maize were detected. Chlorophyll content, photosynthetic characteristics （net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO2 concentration）, and chlorophyll fluorescence parameters in leaves of the inoculated and non-inoculated maize were also determined. Inoculation with G. cylindrosporus significantly increased height, basal diameter, root length, and biomass of maize seedlings under Pb stress. Colonization of G. cylindrosporus improved the efficiency of photosynthesis and altered the translocation and accumulation of Pb in the plants. Although inoculation with G. cylindrosporus increased Pb accumulation in host plants in comparison to non-inoculated plants, the translocation factor of Pb in plant body was significantly decreased. The results indicated that Pb was accumulated mainly in the root system of maize and the phytotoxicity of Pb to the aerial part of the plant was alleviated. The improvement of efficiency of photosynthesis and the decrease of translocation factor of Pb, caused by DSE fungal colonization, were efficient strategies to improve Pb tolerance of host plants.
基金supported by the National Natural Science Foundation of China(31130063)the National Outstanding Young Scholar Science Foundation of China(31025008)to Chai JiJie
文摘Leucine rich repeat(LRR)domain,characterized by a repetitive sequence pattern rich in leucine residues,is a universal protein-protein interaction motif present in all life forms.LRR repeats interrupted by sequences of 30 70 residues(termed island domain,ID)have been found in some plant LRR receptor-like kinases(RLKs)and animal Toll-like receptors(TLR7-9).Recent studies provide insight into how a single ID is structurally integrated into an LRR protein.However,structural information on an LRR protein with two IDs is lacking.The receptor-like protein kinase 2(RPK2)is an LRR-RLK and has important roles in controlling plant growth and development by perception and transduction of hormone signal.Here we present the crystal structure of the extracellular LRR domain of RPK2(RPK2-LRR)containing two IDs from Arabidopsis.The structure reveals that both of the IDs are helical and located at the central region of the single RPK2-LRR solenoid.One of them binds to the inner surface of the solenoid,whereas the other one mainly interacts with the lateral side.Unexpectedly,a long loop immediately following the N-terminal capping domain of RPK2-LRR is presented toward and sandwiched between the two IDs,further stabilizing their embedding to the LRR solenoid.A potential ligand binding site formed by the two IDs and the solenoid is located at the C-terminal side of RPK2-LRR.The structural information of RPK2-LRR broadens our understanding toward the large family of LRR proteins and provides insight into RPK2-mediated signaling.
文摘Soil biotic communities can strongly impact plant performance.In this paper,we ask the question:how longlasting the effect of the soil microbial community on plant growth is.We examined the plant growth rates at three stages:early,mid and late growth.We performed two growth experiments with Jacobaea vulgaris,which lasted 49 and 63 days in sterilized soil or live soil.In a third experiment,we examined the effect of the timing of soil inoculation prior to planting on the relative growth rate of J.vulgaris with four different timing treatments.In all experiments,differences in biomass of plants grown in sterilized soil and live soil increased throughout the experiment.Also,the relative growth rate of plants in the sterilized soil was only significantly higher than that of plants in the live soil in the first two to three weeks.In the third experiment,plant biomass decreased with increasing time between inoculation and planting.Overall,our results showed that plants of J.vulgaris grew less well in live soil than in sterilized soil.The negative effects of soil inoculation on plant mass appeared to extend over the whole growth period but arise from the negative effects on relative growth rates that occurred in the first weeks.
