The objective of this study was to investigate the effects of root cutting stress on the dynamic changes of endogenous hormone content and growth characteristics of Quercus variabilis roots,and to explore the physiolo...The objective of this study was to investigate the effects of root cutting stress on the dynamic changes of endogenous hormone content and growth characteristics of Quercus variabilis roots,and to explore the physiological role of endogenous hormones in regulating root-crown interactions in the short term.The morphological characteristics and endogenous hormone contents of normal roots(no root cutting,CK)and cut roots(cut by 1/3 of the length of the main root,RP)were determined by liquid chromatography,which was combined with mass spectrometry at different levels of different developmental stages.The results showed that the root growth indexes and root endogenous hormones in the RP group were superior to those in the CK group.Through comprehensive analysis of endogenous hormones,it was found that the crosstalk of IAA,JA,ABA and SA could activate the root growth defense.After the root cutting treatment,the root growth of Quercus variabilis seedlings could compensate for the inhibition of taproot growth by promoting lateral root growth.The growth and development of compensatory lateral roots contribute to the increase the total root length of plants,thus promoting the absorption of water and nutrients.It is speculated that plant hormones may be the key factors affecting their development,but this is not only related to the content of a single hormone,but more importantly,it is the interaction between various hormones.展开更多
[Objectives]The paper was to classify natural types of Quercus variabilis and to study its regularity of variation.[Methods]Through the analysis of correlation coefficient matrix of tree age,DBH,tree height,breast hei...[Objectives]The paper was to classify natural types of Quercus variabilis and to study its regularity of variation.[Methods]Through the analysis of correlation coefficient matrix of tree age,DBH,tree height,breast height and bark thickness,petiole length,leaf width and leaf length,the breast height and bark thickness and petiole length were chosen as the main indices for classifying natural types of Q.variabilis.[Results]There were 4 natural types of Q.variabilis in Shaanxi Province,including long-petiole-thick-bark type,short-petiole-thick-bark type,long-petiole-thin-bark type and short-petiole-thin-bark type.The short-petiole-thick-bark type accounted for the largest proportion in Q.variabilis population(34.44%).On the northern slope of Bashan Mountains and the Huanglong Mountains,the short-petiole-thick-bark type was the dominant type,while on the northern slope of Qinling Mountains the long-petiole-thick-bark type accounted for a larger proportion.[Conclusions]This study will provide a basic foundation for making full use of excellent types of Q.variabilis natural resources.展开更多
The slope aspect is one of the most critical topographic factors in mountainous areas.Little is known,however,about the eff ect of the aspect on the ectomycorrhizal(ECM)fungal community.Additionally,we know very littl...The slope aspect is one of the most critical topographic factors in mountainous areas.Little is known,however,about the eff ect of the aspect on the ectomycorrhizal(ECM)fungal community.Additionally,we know very little about the composition of ECM fungal communities associated with Quercus variabilis,which is widely distributed in East Asia.In this study,we compared the richness,community composition,and exploration types of ECM fungi associated with Q.variabilis between predominantly south-and north-facing slopes in the Taihang Mountain,North China for the fi rst time.DNA was extracted from the root tips of Q.variabilis,and Illumina MiSeq sequencing was used to identify ECM fungi.In total,168 operational taxonomic units belonging to 28 genera were detected,and the ECM community was found to be dominated by Russula,Inocybe,Tomentella,Scleroderma,and Cortinarius.Compared with the north-facing slopes,the ECM communities on the south-facing slopes had higher diversity.The community composition and exploration types were directly aff ected by the slope aspect.Also,the aspect-induced edaphic variables,such as total phosphorus,total nitrogen,total potassium,pH,and soil water content,were important sources of variation in ECM fungal richness and distributions of exploration types.Diff erent genera tended to be distributed in various slope aspects.Cenococcum,Genea,and Clavulina were signifi cantly enriched in north-facing slopes,while Geopora,Helvelosebacina,Scleroderma,Gyroporus,Astraeus,Boletus,Tricholoma,Hebeloma,Cortinarius and unclassifi ed Thelephoraceae were more abundant in south-facing slopes.Hydrophobic ECM fungi were obviously enriched in the south-facing slope,but there was no statistical diff erence between hydrophilic among the south-and north-facing slopes.Our study deepened our knowledge of the aspect-driven variation in ECM fungal communities associated with Q.variabilis.展开更多
This study investigated the feasibility of hyperspectral imaging techniques to estimate the vigor of heatdamaged Quercus variabilis seeds.Four thermal damage grades were classified according to heat treatment duration...This study investigated the feasibility of hyperspectral imaging techniques to estimate the vigor of heatdamaged Quercus variabilis seeds.Four thermal damage grades were classified according to heat treatment duration(0,2,5,and 10 h).After obtaining hyperspectral images with a 370–1042 nm hyperspectral imager that included visible and near infrared light,germination was tested to confirm estimates.The Savitzky–Golay(SG)second derivative was used to preprocess the spectrum to reduce any noise impact.The successive projections algorithm(SPA),principal component analysis,and local linear embedding algorithm were used to extract the characteristic spectral bands related to seed vigor.Finally,a model for seed vigor classifi-cation of Q.variabili s based on partial least squares support vector machine(LS-SVM)with different spectral data sets was developed.The results show that the spectrum after SG second derivative preprocessing was better for developing the model,and SPA performed the best among the three feature band selection methods.The combination SG second derivative-LS-SVM provided the best classification model for Q.variabilis seed vigor,with the prediction set reaching 98.81%.This study provides an important basis for rapid and nondestructive assessment of the vigor of heat-damaged seeds using hyperspectral imaging techniques.展开更多
Cephalopods play key roles in global marine ecosystems as both predators and preys.Regressive estimation of original size and weight of cephalopod from beak measurements is a powerful tool of interrogating the feeding...Cephalopods play key roles in global marine ecosystems as both predators and preys.Regressive estimation of original size and weight of cephalopod from beak measurements is a powerful tool of interrogating the feeding ecology of predators at higher trophic levels.In this study,regressive relationships among beak measurements and body length and weight were determined for an octopus species(Octopus variabilis),an important endemic cephalopod species in the northwest Pacific Ocean.A total of 193 individuals(63 males and 130 females) were collected at a monthly interval from Jiaozhou Bay,China.Regressive relationships among 6 beak measurements(upper hood length,UHL;upper crest length,UCL;lower hood length,LHL;lower crest length,LCL;and upper and lower beak weights) and mantle length(ML),total length(TL) and body weight(W) were determined.Results showed that the relationships between beak size and TL and beak size and ML were linearly regressive,while those between beak size and W fitted a power function model.LHL and UCL were the most useful measurements for estimating the size and biomass of O.variabilis.The relationships among beak measurements and body length(either ML or TL) were not significantly different between two sexes;while those among several beak measurements(UHL,LHL and LBW) and body weight(W) were sexually different.Since male individuals of this species have a slightly greater body weight distribution than female individuals,the body weight was not an appropriate measurement for estimating size and biomass,especially when the sex of individuals in the stomachs of predators was unknown.These relationships provided essential information for future use in size and biomass estimation of O.variabilis,as well as the estimation of predator/prey size ratios in the diet of top predators.展开更多
A 4.34 liter two stage air lift photobioreactor incorporating Anabaena variabilis ATCC29413 mutant PK84 was used to study H 2 production. Results showed that H 2 production increased with increasing light intensity fr...A 4.34 liter two stage air lift photobioreactor incorporating Anabaena variabilis ATCC29413 mutant PK84 was used to study H 2 production. Results showed that H 2 production increased with increasing light intensity from 47 μE/(m 2·s) up to 190 μE/(m 2·s), but that further increase of light intensity decreased the H 2 production because of the inhibition due to the high pO 2. The data also indicated that longer argon gas charge resulted in more H 2 produced due to the increase of nitrogenase activities and heterocyst frequency, and that more than 1.3 L net H 2 was produced from this computer controlled photobioreactor.展开更多
H2 photoproduction and nitrogenase activities in two strains of Anabaena variabilismarked wild type ATCC 29413 and mutant PK84 exposed to thermal stress (temperature higher than thenormal incubation temperature of 30...H2 photoproduction and nitrogenase activities in two strains of Anabaena variabilismarked wild type ATCC 29413 and mutant PK84 exposed to thermal stress (temperature higher than thenormal incubation temperature of 30℃) were studied. Cultures of both strains collected from any intervalof logarithmic growth phase exhibited high H2 photoproduction and nitrogenase activities when exposed tolimited time heat shock during the assay process. In contrast, the algal H2 photoproduction rate of bothstrains fluctuated with long term thermal stress caused hy increasing the growth temperature from 30℃ to36℃.The changes of nitrogenase (the key H2 photobiosynhetic enzyme) activities in the mutant PK84showed variation tendency similar to that of H2 photoproduction during exposure to thermal stress, indicat-ing that fluctuation of H2 photopnduction in the mutant was mainly due to the variation of nitrogenase ac-tivities. A temporary maximal H2 photoproduction in the mutant PK84 (wild type ATCC29413 ) was ob-served when cells po at 36℃ for 14 (6) days. However, the responses of nitrogenase activities in thewild type to thermal stress were not completely similar to those in the mutant in spite of similar variationsof H2 photoproduction in both strains. The data obtained in these studies suggested tha the activities ofother enzymes (in the wild strain) involved in H2 photoproduction were affected by thermal stress since H2photoporduction maximized or dropped to 0 without variation tendency similar to that of nitrogenase activi-ties.Furthermore, an enhancement of H2 photoproduction speed of the mutant strain cultured in a 4.4 Llaboratory photobioreactor was also observed when it was subjected to short time continuous charge of ar-gon, and temperature rise.All these results indicated that high temperature plays an important role in the photo-autotrophic H2photoproduction, and that long term thermal stress is unfavourable for net H2 phooproduction in bothstrains of A. variabilis though short-time heat shock is conducive to H2 photoproduction.展开更多
This study examined the effects of increased salinity on growth, development and survival of the Green toad, Bufotes variabilis during embryonic, hatching and early larval periods. Eggs from a single cohort of B. vari...This study examined the effects of increased salinity on growth, development and survival of the Green toad, Bufotes variabilis during embryonic, hatching and early larval periods. Eggs from a single cohort of B. variabilis were subjected to acute and chronic toxicity tests for water salinity ranging from 0.20 to 10 g of salt per liter. Results obtained from this study showed that salinity over 3.70 g/l increased embryonic mortality and reduced percentage of hatching and survival rate of larvae. As larvae tolerated salinity 0.20 to 3.70 g/l with highest survival, but salinity of 10 g/l caused mortality of all individuals within 12 h, 7.70-8.70 （g/l） within 4.5 days, 5.70-6.70 g/l within 10 days and 4.70 （g/l） were tolerated within 14 days. Salinity less than 0.70 g/l did not affect survival and hatching success of the embryos. After a 3-week experiment, size of larvae exposed to salinities over 0.70 g/l was lower compared to larvae reared at lower salinity levels. Meanwhile increases in salinity more than 3.70 g/l caused extension in the hatching period. Larvae reared at salinity of 3.70 to 4.70 g/l had morphological abnormalities, such as distortion of tail.展开更多
基金funded by National Natural Science Foundation of China,Grant Number 31700549China Postdoctoral Science Foundation Project,Grant Number 2017M612401.
文摘The objective of this study was to investigate the effects of root cutting stress on the dynamic changes of endogenous hormone content and growth characteristics of Quercus variabilis roots,and to explore the physiological role of endogenous hormones in regulating root-crown interactions in the short term.The morphological characteristics and endogenous hormone contents of normal roots(no root cutting,CK)and cut roots(cut by 1/3 of the length of the main root,RP)were determined by liquid chromatography,which was combined with mass spectrometry at different levels of different developmental stages.The results showed that the root growth indexes and root endogenous hormones in the RP group were superior to those in the CK group.Through comprehensive analysis of endogenous hormones,it was found that the crosstalk of IAA,JA,ABA and SA could activate the root growth defense.After the root cutting treatment,the root growth of Quercus variabilis seedlings could compensate for the inhibition of taproot growth by promoting lateral root growth.The growth and development of compensatory lateral roots contribute to the increase the total root length of plants,thus promoting the absorption of water and nutrients.It is speculated that plant hormones may be the key factors affecting their development,but this is not only related to the content of a single hormone,but more importantly,it is the interaction between various hormones.
基金National Natural Science Foundation of China(30740059)Western Action Plan Project of Chinese Academy of Sciences(ZCX2-XB2-05)National Key Technology R&D Program(2006BAD09B03).
文摘[Objectives]The paper was to classify natural types of Quercus variabilis and to study its regularity of variation.[Methods]Through the analysis of correlation coefficient matrix of tree age,DBH,tree height,breast height and bark thickness,petiole length,leaf width and leaf length,the breast height and bark thickness and petiole length were chosen as the main indices for classifying natural types of Q.variabilis.[Results]There were 4 natural types of Q.variabilis in Shaanxi Province,including long-petiole-thick-bark type,short-petiole-thick-bark type,long-petiole-thin-bark type and short-petiole-thin-bark type.The short-petiole-thick-bark type accounted for the largest proportion in Q.variabilis population(34.44%).On the northern slope of Bashan Mountains and the Huanglong Mountains,the short-petiole-thick-bark type was the dominant type,while on the northern slope of Qinling Mountains the long-petiole-thick-bark type accounted for a larger proportion.[Conclusions]This study will provide a basic foundation for making full use of excellent types of Q.variabilis natural resources.
文摘为了揭示二酰甘油酰基转移酶(DGAT)在小球藻油脂合成过程中的作用,对单细胞小球藻Chlorella variabilis NC64A的二酰甘油酰基转移酶进行原核克隆表达及功能初步研究。结果表明,其编码序列为894bp,编码297个氨基酸,表达蛋白的表观分子量为33 k Da,p I 9.48。保守结构域分析表明,该蛋白属于Lysophospholipid acyltransferases(LPLATs)超家族,具有二酰甘油酰基转移酶活性,序列位点H68,L71,F76,R94,I97和GAA(144?146)组成特定的酰基受体结合口袋,能够结合酰基?酰基载体蛋白(ACP)或者酰基辅酶A上的酰基,催化三酰甘油合成的最后一步。表达蛋白与Ss PDAT和At PDAT的序列相似性分别为32%和24%,表明该蛋白可能具有磷脂酰甘油酰基转移酶(PDAT)活性,能利用磷脂上的酰基合成三酰甘油。因此,采用薄层层析方法以L-α-磷脂酰胆碱和1,2-二油酰-sn-甘油为底物,检测到其确实具有PDAT活性,表明限氮条件下NC64A中DGAT的PDAT活性可能促进了膜脂降解耦合三酰甘油的合成。
基金the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2015BAD07B02).
文摘The slope aspect is one of the most critical topographic factors in mountainous areas.Little is known,however,about the eff ect of the aspect on the ectomycorrhizal(ECM)fungal community.Additionally,we know very little about the composition of ECM fungal communities associated with Quercus variabilis,which is widely distributed in East Asia.In this study,we compared the richness,community composition,and exploration types of ECM fungi associated with Q.variabilis between predominantly south-and north-facing slopes in the Taihang Mountain,North China for the fi rst time.DNA was extracted from the root tips of Q.variabilis,and Illumina MiSeq sequencing was used to identify ECM fungi.In total,168 operational taxonomic units belonging to 28 genera were detected,and the ECM community was found to be dominated by Russula,Inocybe,Tomentella,Scleroderma,and Cortinarius.Compared with the north-facing slopes,the ECM communities on the south-facing slopes had higher diversity.The community composition and exploration types were directly aff ected by the slope aspect.Also,the aspect-induced edaphic variables,such as total phosphorus,total nitrogen,total potassium,pH,and soil water content,were important sources of variation in ECM fungal richness and distributions of exploration types.Diff erent genera tended to be distributed in various slope aspects.Cenococcum,Genea,and Clavulina were signifi cantly enriched in north-facing slopes,while Geopora,Helvelosebacina,Scleroderma,Gyroporus,Astraeus,Boletus,Tricholoma,Hebeloma,Cortinarius and unclassifi ed Thelephoraceae were more abundant in south-facing slopes.Hydrophobic ECM fungi were obviously enriched in the south-facing slope,but there was no statistical diff erence between hydrophilic among the south-and north-facing slopes.Our study deepened our knowledge of the aspect-driven variation in ECM fungal communities associated with Q.variabilis.
基金funded by the National Natural Science Foundation of China(Grant No.31770769)the National Key Research and Development Program of China(No.2017YFC0504403)the Fundamental Research Funds for the Central Universities(No.2015ZCQ-GX-03).
文摘This study investigated the feasibility of hyperspectral imaging techniques to estimate the vigor of heatdamaged Quercus variabilis seeds.Four thermal damage grades were classified according to heat treatment duration(0,2,5,and 10 h).After obtaining hyperspectral images with a 370–1042 nm hyperspectral imager that included visible and near infrared light,germination was tested to confirm estimates.The Savitzky–Golay(SG)second derivative was used to preprocess the spectrum to reduce any noise impact.The successive projections algorithm(SPA),principal component analysis,and local linear embedding algorithm were used to extract the characteristic spectral bands related to seed vigor.Finally,a model for seed vigor classifi-cation of Q.variabili s based on partial least squares support vector machine(LS-SVM)with different spectral data sets was developed.The results show that the spectrum after SG second derivative preprocessing was better for developing the model,and SPA performed the best among the three feature band selection methods.The combination SG second derivative-LS-SVM provided the best classification model for Q.variabilis seed vigor,with the prediction set reaching 98.81%.This study provides an important basis for rapid and nondestructive assessment of the vigor of heat-damaged seeds using hyperspectral imaging techniques.
基金funded by The National Natural Science Foundation of China(41006083)The Shandong Provincial Natural Science Foundation,China(ZR2010DQ026)+1 种基金The Fundamental Research Funds for the Central Universities(201022001,201262004)The Specialized Research Program for Marine Public Welfare Industry from the State Oceanic Administration,P.R.China(200805066)
文摘Cephalopods play key roles in global marine ecosystems as both predators and preys.Regressive estimation of original size and weight of cephalopod from beak measurements is a powerful tool of interrogating the feeding ecology of predators at higher trophic levels.In this study,regressive relationships among beak measurements and body length and weight were determined for an octopus species(Octopus variabilis),an important endemic cephalopod species in the northwest Pacific Ocean.A total of 193 individuals(63 males and 130 females) were collected at a monthly interval from Jiaozhou Bay,China.Regressive relationships among 6 beak measurements(upper hood length,UHL;upper crest length,UCL;lower hood length,LHL;lower crest length,LCL;and upper and lower beak weights) and mantle length(ML),total length(TL) and body weight(W) were determined.Results showed that the relationships between beak size and TL and beak size and ML were linearly regressive,while those between beak size and W fitted a power function model.LHL and UCL were the most useful measurements for estimating the size and biomass of O.variabilis.The relationships among beak measurements and body length(either ML or TL) were not significantly different between two sexes;while those among several beak measurements(UHL,LHL and LBW) and body weight(W) were sexually different.Since male individuals of this species have a slightly greater body weight distribution than female individuals,the body weight was not an appropriate measurement for estimating size and biomass,especially when the sex of individuals in the stomachs of predators was unknown.These relationships provided essential information for future use in size and biomass estimation of O.variabilis,as well as the estimation of predator/prey size ratios in the diet of top predators.
文摘A 4.34 liter two stage air lift photobioreactor incorporating Anabaena variabilis ATCC29413 mutant PK84 was used to study H 2 production. Results showed that H 2 production increased with increasing light intensity from 47 μE/(m 2·s) up to 190 μE/(m 2·s), but that further increase of light intensity decreased the H 2 production because of the inhibition due to the high pO 2. The data also indicated that longer argon gas charge resulted in more H 2 produced due to the increase of nitrogenase activities and heterocyst frequency, and that more than 1.3 L net H 2 was produced from this computer controlled photobioreactor.
文摘H2 photoproduction and nitrogenase activities in two strains of Anabaena variabilismarked wild type ATCC 29413 and mutant PK84 exposed to thermal stress (temperature higher than thenormal incubation temperature of 30℃) were studied. Cultures of both strains collected from any intervalof logarithmic growth phase exhibited high H2 photoproduction and nitrogenase activities when exposed tolimited time heat shock during the assay process. In contrast, the algal H2 photoproduction rate of bothstrains fluctuated with long term thermal stress caused hy increasing the growth temperature from 30℃ to36℃.The changes of nitrogenase (the key H2 photobiosynhetic enzyme) activities in the mutant PK84showed variation tendency similar to that of H2 photoproduction during exposure to thermal stress, indicat-ing that fluctuation of H2 photopnduction in the mutant was mainly due to the variation of nitrogenase ac-tivities. A temporary maximal H2 photoproduction in the mutant PK84 (wild type ATCC29413 ) was ob-served when cells po at 36℃ for 14 (6) days. However, the responses of nitrogenase activities in thewild type to thermal stress were not completely similar to those in the mutant in spite of similar variationsof H2 photoproduction in both strains. The data obtained in these studies suggested tha the activities ofother enzymes (in the wild strain) involved in H2 photoproduction were affected by thermal stress since H2photoporduction maximized or dropped to 0 without variation tendency similar to that of nitrogenase activi-ties.Furthermore, an enhancement of H2 photoproduction speed of the mutant strain cultured in a 4.4 Llaboratory photobioreactor was also observed when it was subjected to short time continuous charge of ar-gon, and temperature rise.All these results indicated that high temperature plays an important role in the photo-autotrophic H2photoproduction, and that long term thermal stress is unfavourable for net H2 phooproduction in bothstrains of A. variabilis though short-time heat shock is conducive to H2 photoproduction.
基金the Razi University for the support of this study as an MSc research project
文摘This study examined the effects of increased salinity on growth, development and survival of the Green toad, Bufotes variabilis during embryonic, hatching and early larval periods. Eggs from a single cohort of B. variabilis were subjected to acute and chronic toxicity tests for water salinity ranging from 0.20 to 10 g of salt per liter. Results obtained from this study showed that salinity over 3.70 g/l increased embryonic mortality and reduced percentage of hatching and survival rate of larvae. As larvae tolerated salinity 0.20 to 3.70 g/l with highest survival, but salinity of 10 g/l caused mortality of all individuals within 12 h, 7.70-8.70 （g/l） within 4.5 days, 5.70-6.70 g/l within 10 days and 4.70 （g/l） were tolerated within 14 days. Salinity less than 0.70 g/l did not affect survival and hatching success of the embryos. After a 3-week experiment, size of larvae exposed to salinities over 0.70 g/l was lower compared to larvae reared at lower salinity levels. Meanwhile increases in salinity more than 3.70 g/l caused extension in the hatching period. Larvae reared at salinity of 3.70 to 4.70 g/l had morphological abnormalities, such as distortion of tail.
