Soybean root diseases are associated with numerous fungal and oomycete pathogens;however,the community dynamics and interactions of these pathogens are largely unknown.We performed 13 loop-mediated isothermal amplific...Soybean root diseases are associated with numerous fungal and oomycete pathogens;however,the community dynamics and interactions of these pathogens are largely unknown.We performed 13 loop-mediated isothermal amplification(LAMP)assays that targeted specific soybean root pathogens,and traditional isolation assays.A total of 159 samples were collected from three locations in the Huang-Huai-Hai region of China at three soybean growth stages(30,60,and 90 days after planting)in 2016.In LAMP results,we found that pathogen communities differed slightly among locations,but changed dramatically between soybean growth stages.Phytophthora sojae,Rhizoctonia solani,and Fusarium oxysporum were most frequently detected at the early stage,whereas Phomopsis longicolla,Fusarium equiseti,and Fusarium virguliforme were most common in the later stages.Most samples(86%)contained two to six pathogen species.Interestingly,the less detectable species tended to exist in the samples containing more detected species,and some pathogens preferentially co-occurred in diseased tissue,including P.sojae–R.solani–F.oxysporum and F.virguliforme–Calonectria ilicicola,implying potential interactions during infection.The LAMP detection results were confirmed by traditional isolation methods.The isolated strains exhibited different virulence to soybean,further implying a beneficial interaction among some pathogens.展开更多
This paper mainly focused on the growth law, model construction and visualization of a soybean root. A pot experiment was conducted in the laboratory to collect root system data and measure soybean root＇s length, dia...This paper mainly focused on the growth law, model construction and visualization of a soybean root. A pot experiment was conducted in the laboratory to collect root system data and measure soybean root＇s length, diameter and number by excavating in different periods. On the basis of an in-depth analysis of root structure geometry, we analyzed the collected experimental data with logistic equations, and got the growth of soybean root equation, according to its morphological structure characteristics of self-similarity, and discussed the virtual modeling method on the soybean root based on L-system and in Visual c＋＋ Using OpenGL technology to achieve a soybean root system topology model and visualization simulation.展开更多
Plough pans （PPs）, common in the black-soil region of northeastern China, have significant effects on the root systems of crops. We conducted a field experiment to study the distribution of soybean roots under the i...Plough pans （PPs）, common in the black-soil region of northeastern China, have significant effects on the root systems of crops. We conducted a field experiment to study the distribution of soybean roots under the influence of PPs. The soybean roots showed compensatory growth above the PP, with higher root length and weight in soil with a PP compared to those without a PP. Roots were heavier and longer in the 15-75 cm soil layer without a PP than with a PP. Soil porosity was lower in the PP and the soil below the PP, which likely decreased the oxygen content of the soil and induced more growth of roots above the PP. The PP is also likely to decrease infiltration of rain-water and hinder the migration of nitrate downward, which in turn increased the density and length of soybean root hairs, which, hence, promoted growth.展开更多
Soil suppressiveness to Fusarium root rot of soybean had been observed in a black soil field after a long-term fertilization with nitrogen(N)and phosphorus(P)fertilizer combined with pig manure as organic amendment(NP...Soil suppressiveness to Fusarium root rot of soybean had been observed in a black soil field after a long-term fertilization with nitrogen(N)and phosphorus(P)fertilizer combined with pig manure as organic amendment(NPM),rather than that with only nitrogen and phosphorus fertilizer(NP)or no fertilizer(NF).To determine the microbial role on this suppressiveness,fungal and bacterial community characteristics in NPM,NP and NF treatments were investigated by q PCR and DGGE.Compared with the similar bacterial community characteristics among 3 treatments,fungal community,especially Fusarium population size and community composition in NPM treatment were different with those of NP and NF groups.Based on the isolation and pathogenicity test,pathogenic F.oxysporum,F.graminearum,F.verticillioide and F.lateritium absolutely dominated Fusarium community in NF and NP groups.Nonpathogenic F.avenaceum,F.equiseti,F.culmorum,F.redolens,F.solani and F.tricinctum dominated Fusarium community in NPM group.Isolation rate of pathogenic Fusarium in NPM reduced from 100%to 38%in NF.These results suggested that the dominance of soil non-pathogenic Fusarium population induced by organic amendment might play an important role on suppressing Fusarium root rot in the tested field.展开更多
The efficiency of N2-fixation in legume-rhizobia symbiosis is a function of root nodule activity.Nodules consist of 2 functionally important tissues:(a)a central infected zone(CIZ),colonized by rhizobia bacteria,which...The efficiency of N2-fixation in legume-rhizobia symbiosis is a function of root nodule activity.Nodules consist of 2 functionally important tissues:(a)a central infected zone(CIZ),colonized by rhizobia bacteria,which serves as the site of N2-fixation,and(b)vascular bundles(VBs),serving as conduits for the transport of water,nutrients,and fixed nitrogen compounds between the nodules and plant.A quantitative evaluation of these tissues is essential to unravel their functional importance in N2-fixation.Employing synchrotron-based x-ray microcomputed tomography(SR-μCT)at submicron resolutions,we obtained high-quality tomograms of fresh soybean root nodules in a non-invasive manner.A semi-automated segmentation algorithm was employed to generate 3-dimensional(3D)models of the internal root nodule structure of the CIZ and VBs,and their volumes were quantified based on the reconstructed 3D structures.Furthermore,synchrotron x-ray fluorescence imaging revealed a distinctive localization of Fe within CIZ tissue and Zn within VBs,allowing for their visualization in 2 dimensions.This study represents a pioneer application of the SR-μCT technique for volumetric quantification of CIZ and VB tissues in fresh,intact soybean root nodules.The proposed methods enable the exploitation of root nodule's anatomical features as novel traits in breeding,aiming to enhance N2-fixation through improved root nodule activity.展开更多
Glycogen synthase kinase 3(GSK3)is a kind of sedne/threonine kinase widely found in eukaryotes.Many plant GSK3 kinases play important roles in regulating stress responses.This study investigated BRASSINOSTEROID-INSENS...Glycogen synthase kinase 3(GSK3)is a kind of sedne/threonine kinase widely found in eukaryotes.Many plant GSK3 kinases play important roles in regulating stress responses.This study investigated BRASSINOSTEROID-INSENSITIVE 2(GmBIN2)gene,a member of the GSK3 protein kinase family in soybean and an orthologue of Arabidopsis BIN2/AtSK21.GmBIN2 expression was increased by salt and drought stresses,but was not significantly affected by the ABA treatment.To examine the function of GrnBIN2,transgenic Arabidopsis and transgenic soybean hairy roots were generated.Overexpression of GmBIN2 in Arabidopsis resulted in increased germination rate and root length compared with wild-type plants under salt and mannitol treatments.Overexpression of GmBIN2 increased cellular Ca2~content and reduced Na~content,enhancing salt tolerance in transgenic Arabidopsis plants.In the soybean hairy root assay,overexpression of GmBIN2 in transgenic roots also showed significantly higher relative root growth rate than the control when subjected to salt and mannitol treatments.Measurement of physiological indicators,including proline content,superoxide dismutase(SOD)activity,and relative electrical conductivity,supported this conclusion.Furthermore,we also found that GmBIN2 could up-regulate the expression of some stress-related genes in transgenic Arabidopsis and soybean hairy roots.Overall,these results indicated that GmBIN2 improved tolerance to salt and drought in transgenic Arabidopsis and soybean hairy roots.展开更多
The NAC （NAM, ATAF1/2 and CUC2） transcription factor family plays a key role in plant development and responses to abiotic stress. GmNAC15 （Glyma 15g40510.1）, a member of the NAC transcription factor family in soy...The NAC （NAM, ATAF1/2 and CUC2） transcription factor family plays a key role in plant development and responses to abiotic stress. GmNAC15 （Glyma 15g40510.1）, a member of the NAC transcription factor family in soybean, was functionally characterized, especially with regard to its role in salt tolerance. In the present study, qRT-PCR （quantitative reverse transcription PCR） analysis indicated that GmNAC15 was induced by salt, drought, low temperature stress, and ABA treatment in roots and leaves. GmNAC15 overexpression in soybean （Glycine max） hairy roots enhanced salt tolerance. Transgenic hairy roots improved the survival of wild leaves; however, overexpression of GmNAC15 in hairy root couldn＇t influnce the expression level of GmNAC15 in leaf. GmNAC15 regulates the expression levels of genes responsive to salt stress. Altogether, these results provide experimental evidence of the positive effect of GmNAC15 on salt tolerance in soybean and the potential application of genetic manipulation to enhance the salt tolerance of important crops.展开更多
Soybean is one of the world's most important oil and protein crops. Efficient transformation is a key factor for the improvement of soybean by genetic modification. We describe an optimized protocol for the Agroba...Soybean is one of the world's most important oil and protein crops. Efficient transformation is a key factor for the improvement of soybean by genetic modification. We describe an optimized protocol for the Agrobacterium rhizogenes-mediated transformation of soybean and the induction of hairy root development in vitro. Cotyledons with 0.5-cm hypocotyls were cut from 5-day-old seedlings and used as explants. After infection and co-cultivation,hairy roots were produced in induction culture medium after 10–12 days. Using this method, 90%–99% of the infected explants of five different cultivars produced hairy roots within one month. Observations using reporter constructs showed that 30%–60% of the hairy roots induced were transformed. Based on high transformation efficiency and short transformation period, this method represents an efficient and rapid platform for study of soybean gene function.展开更多
The aim of the study was to establish a set of differential strains and to identify soybean resistant genes to Phytophthora root rot and then to apply those strains for analysis of the resistant genes Rps1a,Rps1c,and ...The aim of the study was to establish a set of differential strains and to identify soybean resistant genes to Phytophthora root rot and then to apply those strains for analysis of the resistant genes Rps1a,Rps1c,and Rps1k that soybean cultivars or lines may carry.Virulence formula of 125 Phytophthora sojae isolates were determined using the hypocotyls inoculation technique,the strains,which includ 6 isolates with different virulence formulas,were applied to identify the resistance of 55 soybean cultivars or lines and resistant genes were analyzed using the gene postulating procedure.Eighteen reaction types occurred in 55 cultivars or lines and results of gene postulation indicated that 2 cultivars or lines probably carried gene Rps1c and no cultivar may carry genes Rps1a or Rps1k.A few of soybean cultivars or lines from Huanghuai Region carry Rps genes Rps1a,Rps1c and Rps1k and tend to infect by P.sojae,so resistant cultivars or lines need to be bred and popularized actively.展开更多
It was studied that the evolution of root characteristics among 42 soybean varieties developed in Heilongjiang and Jilin Province in different years. The results showed that there were differences on the root characte...It was studied that the evolution of root characteristics among 42 soybean varieties developed in Heilongjiang and Jilin Province in different years. The results showed that there were differences on the root characteristics among soybean varieties. From 1950s to 1990s, root fresh weight, root volume, root surface, root dry weight, lateral root length of main root characters tendedly increased with the variable development展开更多
Excess soil moisture induces hypoxic conditions and causes waterlogging injury in soybean [Glycine max (L.) Merr.]. This study investigated the mechanism underlying the development of waterlogging injury. Nine Japanes...Excess soil moisture induces hypoxic conditions and causes waterlogging injury in soybean [Glycine max (L.) Merr.]. This study investigated the mechanism underlying the development of waterlogging injury. Nine Japanese soybean cultivars with varying degrees of waterlogging tolerance were grown in a hydroponic system for 14 days under hypoxic conditions. Shoot and root biomasses and root hydraulic conductivity were measured at an early vegetative stage for plants under control and hypoxic conditions. Root morphological traits and intramembrane aquaporin proteins were also analyzed. The tolerance of each cultivar to field waterlogging was based on biomass changes induced by the hypoxia treatment. Root hydraulic conductivity responses to hypoxia were associated with changes in total dry weight, leaf dry weight, and leaf area. The effects of hypoxic conditions on root hydraulic conductivity were also represented by the changes in root morphology, such as total root length, thick-root length, and number of root tips. Additionally, a 32.3 kDa aquaporin-like protein seemed to regulate root hydraulic conductivity. Our results from a hydroponic culture suggest that the soybean cultivar-specific responses to hypoxic conditions in the rhizosphere reflect fluctuations in hydraulic conductivity related to root morphological or qualitative changes.展开更多
Fusarium is usually thought to cause soybean root rot, which results in a large quantity of annual yield loss in soybean production, by its secretions including Fusarium toxins and cell wall degrading enzymes, but not...Fusarium is usually thought to cause soybean root rot, which results in a large quantity of annual yield loss in soybean production, by its secretions including Fusarium toxins and cell wall degrading enzymes, but not by the conidia themselves that do not underlie any virulence so far. Here we report that the conidia of one Fusarium solani isolate are able to be virulent to soybean and make soybean seedlings wilted alone. We isolated them from the wilted plants in a soybean-production field and molecularly identified 17 Fusarium isolates through phylogenetic analysis. Of them, except for one isolate that showed diversity of virulence to different soybeans （virulent to one soybean whereas avirulent to another soybean）, the others were all virulent to the two tested soybeans： both conidia cultures and secretions could make soybean seedlings wilted at 5 days post infection, and their virulence had dosage effects that only conidia cultures of at least 5×10^6 conidia mL-1 could show virulence to soybean; however, the sole conidia of the F. solani isolate #4 also exhibited virulence to soybean and could make soybean seedlings wilted. Finally, we developed the specific cleaved amplified polymorphic sequences （CAPS） markers to easily differentiate Fusarium isolates. The isolate #4 in this work will likely be used to investigate the new mechanism of virulence of Fusarium to soybean.展开更多
Soybean is one of the most important sources of edible oil and proteins in the world. However, it suffers from many kinds of fungal diseases which is a major limiting factor in soybean production. The fungal disease c...Soybean is one of the most important sources of edible oil and proteins in the world. However, it suffers from many kinds of fungal diseases which is a major limiting factor in soybean production. The fungal disease can be effectively controlled by breeding plant cultivars with genetic transformation. In this study, the resistance to Phytophthora sojae of five bivalent transgenic soybean lines was identified using the hypocotyls inoculation technique. The lines were the T2 of the transgenic soybean which were transformed with kidney bean chitinase gene and barley ribosome inactivating protein gene, and were positive by Southern Blot analysis. The resistance difference was studied through comparing the death percentage of transgenic soybean with the control. The results showed that four lines were more resistant to P sojae, whereas other one had no significant difference in comparison with the control. These transgenic soybean lines with enhanced resistance to P sojae will be useful in soybean resistance breeding.展开更多
Soybean genotypes show diverse physiological responses to drought, but specific physiological traits that can be used to evaluate drought tolerance have not been identified. In the present study we investigated physio...Soybean genotypes show diverse physiological responses to drought, but specific physiological traits that can be used to evaluate drought tolerance have not been identified. In the present study we investigated physiological traits of soybean genotypes under progressive soil drying and rewetting, using a treatment mimicking field conditions.After a preliminary study with eight soybean genotypes, two drought-tolerant genotypes and one susceptible genotype were grown in the greenhouse and subjected to water restriction. Leaf expansion rate, gas exchange, water relation parameters, total chlorophyll(Chl), proline contents of leaves, and root xylem p H were monitored in a time course, and plant growth and root traits were measured at the end of the stress cycle. Drought-tolerant genotypes maintained higher leaf expansion rate, net photosynthetic rate(Pn), Chl content,instantaneous water use efficiency(WUEi), % relative water content(RWC), water potential(ψw), and turgor potential(ψp) during progressive soil drying and subsequent rewetting than the susceptible genotypes. By contrast, stomatal conductance(gs) and transpiration rate(Tr)of tolerant genotypes declined faster owing to dehydration and recovered more sharply after rehydration than the same parameters in susceptible ones. Water stress caused a significant increase in leaf proline level and root xylem sap p H of both genotypes but tolerant genotypes recovered to pre-stress levels more quickly after rehydration. Tolerant genotypes also produced longer roots with higher dry mass than susceptible genotypes. We conclude that rapid perception and adjustment in response to soil drying and rewetting as well as the maintenance of relatively high Pn, %RWC, and root growth constitute the mechanisms by which drought-tolerant soybean genotypes cope with water stress.展开更多
Soybean [<em>Glycine max</em> (L.) Merrill] seed yields in the northern United States may increase with the application of fertilizers;however Nitrogen (N) may decrease root nodulation. This study was cond...Soybean [<em>Glycine max</em> (L.) Merrill] seed yields in the northern United States may increase with the application of fertilizers;however Nitrogen (N) may decrease root nodulation. This study was conducted to understand the impact of N and sulfur (S) fertilization on soybean nodulation, plant, shoot and root biomass. Two cultivars were planted in experiments across ten site-years during 2015-2016. Plant observations took place at the V4 and R4 soybean growth stages. There were 41% more nodules per plant at R4 compared to V4 (38.3 vs 27.2 nodules, respectively). Cultivars responded differently to N and S fertilizer. The nodules per plant between the cultivars (30.3 vs 24.4) were different as well as the percent medium and large-sized nodules, which indicates the need to evaluate additional genotypes. Adding N decreased root nodulation (from 31.8 to 23.7 nodules per plant) and decreased nodule size but had no effect on plant, shoot or root mass. Averaged across N rates total plant mass was 2.26 and 11.36 g per plant at V4 and R4, respectively. Shoot mass, average across N rates was 1.77 and 9.65 g per plant at V4 and R4, respectively, and root mass, average across N rates was 0.49 and 1.71 g per plant at V4 and R4, respectively. Sulfur did not have an effect on nodules per plant but increased the percent medium size nodules at the R4 observation. There was no N by S interaction observed for nodule number, size of the nodules, and plant, root and shoot mass. As cultivars differed in their nodulation response to N and S, additional research would be helpful to screen other cultivars.展开更多
基金supported by the grants to Prof.Zheng Xiaobo and Prof.Wang Yuanchao from the National Key R&D Program of China(2018YFD0201000)the earmarked fund for China Agriculture Research System(CARS-004-PS14)+1 种基金the National Natural Science Foundation of China(31721004)by the grant to Associate Prof.Ye Wenwu from the National Natural Science Foundation of China(31772140)。
文摘Soybean root diseases are associated with numerous fungal and oomycete pathogens;however,the community dynamics and interactions of these pathogens are largely unknown.We performed 13 loop-mediated isothermal amplification(LAMP)assays that targeted specific soybean root pathogens,and traditional isolation assays.A total of 159 samples were collected from three locations in the Huang-Huai-Hai region of China at three soybean growth stages(30,60,and 90 days after planting)in 2016.In LAMP results,we found that pathogen communities differed slightly among locations,but changed dramatically between soybean growth stages.Phytophthora sojae,Rhizoctonia solani,and Fusarium oxysporum were most frequently detected at the early stage,whereas Phomopsis longicolla,Fusarium equiseti,and Fusarium virguliforme were most common in the later stages.Most samples(86%)contained two to six pathogen species.Interestingly,the less detectable species tended to exist in the samples containing more detected species,and some pathogens preferentially co-occurred in diseased tissue,including P.sojae–R.solani–F.oxysporum and F.virguliforme–Calonectria ilicicola,implying potential interactions during infection.The LAMP detection results were confirmed by traditional isolation methods.The isolated strains exhibited different virulence to soybean,further implying a beneficial interaction among some pathogens.
基金Supported by the Scientific Research Project of Heilongjiang Province(11551054)
文摘This paper mainly focused on the growth law, model construction and visualization of a soybean root. A pot experiment was conducted in the laboratory to collect root system data and measure soybean root＇s length, diameter and number by excavating in different periods. On the basis of an in-depth analysis of root structure geometry, we analyzed the collected experimental data with logistic equations, and got the growth of soybean root equation, according to its morphological structure characteristics of self-similarity, and discussed the virtual modeling method on the soybean root based on L-system and in Visual c＋＋ Using OpenGL technology to achieve a soybean root system topology model and visualization simulation.
基金supported by the National Natural Science Foundation of China (51239009,41301288,51479032 and 51409213)the Postdoctoral Science Foundation of China (2014M561317)+2 种基金the Heilongjiang Postdoctoral Financial Assistance,China (LBH-Z13023)the Heilongjiang Provincial Department of Education Science and Technology Research Project,China (12541039)the Young Talents Project of Northeast Agricultural University,China (14QC48)
文摘Plough pans （PPs）, common in the black-soil region of northeastern China, have significant effects on the root systems of crops. We conducted a field experiment to study the distribution of soybean roots under the influence of PPs. The soybean roots showed compensatory growth above the PP, with higher root length and weight in soil with a PP compared to those without a PP. Roots were heavier and longer in the 15-75 cm soil layer without a PP than with a PP. Soil porosity was lower in the PP and the soil below the PP, which likely decreased the oxygen content of the soil and induced more growth of roots above the PP. The PP is also likely to decrease infiltration of rain-water and hinder the migration of nitrate downward, which in turn increased the density and length of soybean root hairs, which, hence, promoted growth.
基金financially supported by the National Natural Science Foundation of China(41571253,41503068,31770543)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD-2018-87)Initial Scientific Research Fund of Senior Talents in Jiangsu University(15JDG016,15JDG018)。
文摘Soil suppressiveness to Fusarium root rot of soybean had been observed in a black soil field after a long-term fertilization with nitrogen(N)and phosphorus(P)fertilizer combined with pig manure as organic amendment(NPM),rather than that with only nitrogen and phosphorus fertilizer(NP)or no fertilizer(NF).To determine the microbial role on this suppressiveness,fungal and bacterial community characteristics in NPM,NP and NF treatments were investigated by q PCR and DGGE.Compared with the similar bacterial community characteristics among 3 treatments,fungal community,especially Fusarium population size and community composition in NPM treatment were different with those of NP and NF groups.Based on the isolation and pathogenicity test,pathogenic F.oxysporum,F.graminearum,F.verticillioide and F.lateritium absolutely dominated Fusarium community in NF and NP groups.Nonpathogenic F.avenaceum,F.equiseti,F.culmorum,F.redolens,F.solani and F.tricinctum dominated Fusarium community in NPM group.Isolation rate of pathogenic Fusarium in NPM reduced from 100%to 38%in NF.These results suggested that the dominance of soil non-pathogenic Fusarium population induced by organic amendment might play an important role on suppressing Fusarium root rot in the tested field.
基金supported by funding from a Canada Excellence Research Chairs(CERC)Grant to L.K.from funding from the Global Institute for Food Security and the University of Saskatchewan,to L.K.
文摘The efficiency of N2-fixation in legume-rhizobia symbiosis is a function of root nodule activity.Nodules consist of 2 functionally important tissues:(a)a central infected zone(CIZ),colonized by rhizobia bacteria,which serves as the site of N2-fixation,and(b)vascular bundles(VBs),serving as conduits for the transport of water,nutrients,and fixed nitrogen compounds between the nodules and plant.A quantitative evaluation of these tissues is essential to unravel their functional importance in N2-fixation.Employing synchrotron-based x-ray microcomputed tomography(SR-μCT)at submicron resolutions,we obtained high-quality tomograms of fresh soybean root nodules in a non-invasive manner.A semi-automated segmentation algorithm was employed to generate 3-dimensional(3D)models of the internal root nodule structure of the CIZ and VBs,and their volumes were quantified based on the reconstructed 3D structures.Furthermore,synchrotron x-ray fluorescence imaging revealed a distinctive localization of Fe within CIZ tissue and Zn within VBs,allowing for their visualization in 2 dimensions.This study represents a pioneer application of the SR-μCT technique for volumetric quantification of CIZ and VB tissues in fresh,intact soybean root nodules.The proposed methods enable the exploitation of root nodule's anatomical features as novel traits in breeding,aiming to enhance N2-fixation through improved root nodule activity.
基金supported by the funding from the Creative Research Groups of Heilongjiang Province of China(JC2016004)the National Key R&D Program of China(2016YFD0100201-21)+1 种基金the Project of Outstanding Academic Leaders in Harbin,China(2015RQXXJ018)the China Agriculture Collaborative Creation Research System of Miscellaneous Grain Crops
文摘Glycogen synthase kinase 3(GSK3)is a kind of sedne/threonine kinase widely found in eukaryotes.Many plant GSK3 kinases play important roles in regulating stress responses.This study investigated BRASSINOSTEROID-INSENSITIVE 2(GmBIN2)gene,a member of the GSK3 protein kinase family in soybean and an orthologue of Arabidopsis BIN2/AtSK21.GmBIN2 expression was increased by salt and drought stresses,but was not significantly affected by the ABA treatment.To examine the function of GrnBIN2,transgenic Arabidopsis and transgenic soybean hairy roots were generated.Overexpression of GmBIN2 in Arabidopsis resulted in increased germination rate and root length compared with wild-type plants under salt and mannitol treatments.Overexpression of GmBIN2 increased cellular Ca2~content and reduced Na~content,enhancing salt tolerance in transgenic Arabidopsis plants.In the soybean hairy root assay,overexpression of GmBIN2 in transgenic roots also showed significantly higher relative root growth rate than the control when subjected to salt and mannitol treatments.Measurement of physiological indicators,including proline content,superoxide dismutase(SOD)activity,and relative electrical conductivity,supported this conclusion.Furthermore,we also found that GmBIN2 could up-regulate the expression of some stress-related genes in transgenic Arabidopsis and soybean hairy roots.Overall,these results indicated that GmBIN2 improved tolerance to salt and drought in transgenic Arabidopsis and soybean hairy roots.
基金supported by the National Key Research and Development Program of China (2016YFD0101005)the Agricultural Science and Technology Program for Innovation Team on Identification and excavation of Elite Crop Germplasm, Chinese Academy of Agricultural Sciences
文摘The NAC （NAM, ATAF1/2 and CUC2） transcription factor family plays a key role in plant development and responses to abiotic stress. GmNAC15 （Glyma 15g40510.1）, a member of the NAC transcription factor family in soybean, was functionally characterized, especially with regard to its role in salt tolerance. In the present study, qRT-PCR （quantitative reverse transcription PCR） analysis indicated that GmNAC15 was induced by salt, drought, low temperature stress, and ABA treatment in roots and leaves. GmNAC15 overexpression in soybean （Glycine max） hairy roots enhanced salt tolerance. Transgenic hairy roots improved the survival of wild leaves; however, overexpression of GmNAC15 in hairy root couldn＇t influnce the expression level of GmNAC15 in leaf. GmNAC15 regulates the expression levels of genes responsive to salt stress. Altogether, these results provide experimental evidence of the positive effect of GmNAC15 on salt tolerance in soybean and the potential application of genetic manipulation to enhance the salt tolerance of important crops.
基金supported by the Major Science and Technology Projects of China (2016ZX08010-004)the Ministry of Science and Technology of China (2016YFD0100504)the CAAS (Chinese Academy of Agriculture Sciences) Innovation Project
文摘Soybean is one of the world's most important oil and protein crops. Efficient transformation is a key factor for the improvement of soybean by genetic modification. We describe an optimized protocol for the Agrobacterium rhizogenes-mediated transformation of soybean and the induction of hairy root development in vitro. Cotyledons with 0.5-cm hypocotyls were cut from 5-day-old seedlings and used as explants. After infection and co-cultivation,hairy roots were produced in induction culture medium after 10–12 days. Using this method, 90%–99% of the infected explants of five different cultivars produced hairy roots within one month. Observations using reporter constructs showed that 30%–60% of the hairy roots induced were transformed. Based on high transformation efficiency and short transformation period, this method represents an efficient and rapid platform for study of soybean gene function.
基金funded by the Soybean Industrial Science and Technology System of China (Nycytx-004)
文摘The aim of the study was to establish a set of differential strains and to identify soybean resistant genes to Phytophthora root rot and then to apply those strains for analysis of the resistant genes Rps1a,Rps1c,and Rps1k that soybean cultivars or lines may carry.Virulence formula of 125 Phytophthora sojae isolates were determined using the hypocotyls inoculation technique,the strains,which includ 6 isolates with different virulence formulas,were applied to identify the resistance of 55 soybean cultivars or lines and resistant genes were analyzed using the gene postulating procedure.Eighteen reaction types occurred in 55 cultivars or lines and results of gene postulation indicated that 2 cultivars or lines probably carried gene Rps1c and no cultivar may carry genes Rps1a or Rps1k.A few of soybean cultivars or lines from Huanghuai Region carry Rps genes Rps1a,Rps1c and Rps1k and tend to infect by P.sojae,so resistant cultivars or lines need to be bred and popularized actively.
文摘It was studied that the evolution of root characteristics among 42 soybean varieties developed in Heilongjiang and Jilin Province in different years. The results showed that there were differences on the root characteristics among soybean varieties. From 1950s to 1990s, root fresh weight, root volume, root surface, root dry weight, lateral root length of main root characters tendedly increased with the variable development
文摘Excess soil moisture induces hypoxic conditions and causes waterlogging injury in soybean [Glycine max (L.) Merr.]. This study investigated the mechanism underlying the development of waterlogging injury. Nine Japanese soybean cultivars with varying degrees of waterlogging tolerance were grown in a hydroponic system for 14 days under hypoxic conditions. Shoot and root biomasses and root hydraulic conductivity were measured at an early vegetative stage for plants under control and hypoxic conditions. Root morphological traits and intramembrane aquaporin proteins were also analyzed. The tolerance of each cultivar to field waterlogging was based on biomass changes induced by the hypoxia treatment. Root hydraulic conductivity responses to hypoxia were associated with changes in total dry weight, leaf dry weight, and leaf area. The effects of hypoxic conditions on root hydraulic conductivity were also represented by the changes in root morphology, such as total root length, thick-root length, and number of root tips. Additionally, a 32.3 kDa aquaporin-like protein seemed to regulate root hydraulic conductivity. Our results from a hydroponic culture suggest that the soybean cultivar-specific responses to hypoxic conditions in the rhizosphere reflect fluctuations in hydraulic conductivity related to root morphological or qualitative changes.
基金financially supported by the Innovation Program and Youth Elite Program of Chinese Academy of Agricultural Sciences
文摘Fusarium is usually thought to cause soybean root rot, which results in a large quantity of annual yield loss in soybean production, by its secretions including Fusarium toxins and cell wall degrading enzymes, but not by the conidia themselves that do not underlie any virulence so far. Here we report that the conidia of one Fusarium solani isolate are able to be virulent to soybean and make soybean seedlings wilted alone. We isolated them from the wilted plants in a soybean-production field and molecularly identified 17 Fusarium isolates through phylogenetic analysis. Of them, except for one isolate that showed diversity of virulence to different soybeans （virulent to one soybean whereas avirulent to another soybean）, the others were all virulent to the two tested soybeans： both conidia cultures and secretions could make soybean seedlings wilted at 5 days post infection, and their virulence had dosage effects that only conidia cultures of at least 5×10^6 conidia mL-1 could show virulence to soybean; however, the sole conidia of the F. solani isolate #4 also exhibited virulence to soybean and could make soybean seedlings wilted. Finally, we developed the specific cleaved amplified polymorphic sequences （CAPS） markers to easily differentiate Fusarium isolates. The isolate #4 in this work will likely be used to investigate the new mechanism of virulence of Fusarium to soybean.
基金Supported by the National Items of Research and Industrial Development of Transgenic Plants(J99-B-013)
文摘Soybean is one of the most important sources of edible oil and proteins in the world. However, it suffers from many kinds of fungal diseases which is a major limiting factor in soybean production. The fungal disease can be effectively controlled by breeding plant cultivars with genetic transformation. In this study, the resistance to Phytophthora sojae of five bivalent transgenic soybean lines was identified using the hypocotyls inoculation technique. The lines were the T2 of the transgenic soybean which were transformed with kidney bean chitinase gene and barley ribosome inactivating protein gene, and were positive by Southern Blot analysis. The resistance difference was studied through comparing the death percentage of transgenic soybean with the control. The results showed that four lines were more resistant to P sojae, whereas other one had no significant difference in comparison with the control. These transgenic soybean lines with enhanced resistance to P sojae will be useful in soybean resistance breeding.
基金supported by the Hong Kong RGC Collaborative Research Fund (CUHK3/CRF/ 11G) to Prof. H.-M. Lam. and J.H. Zhang
文摘Soybean genotypes show diverse physiological responses to drought, but specific physiological traits that can be used to evaluate drought tolerance have not been identified. In the present study we investigated physiological traits of soybean genotypes under progressive soil drying and rewetting, using a treatment mimicking field conditions.After a preliminary study with eight soybean genotypes, two drought-tolerant genotypes and one susceptible genotype were grown in the greenhouse and subjected to water restriction. Leaf expansion rate, gas exchange, water relation parameters, total chlorophyll(Chl), proline contents of leaves, and root xylem p H were monitored in a time course, and plant growth and root traits were measured at the end of the stress cycle. Drought-tolerant genotypes maintained higher leaf expansion rate, net photosynthetic rate(Pn), Chl content,instantaneous water use efficiency(WUEi), % relative water content(RWC), water potential(ψw), and turgor potential(ψp) during progressive soil drying and subsequent rewetting than the susceptible genotypes. By contrast, stomatal conductance(gs) and transpiration rate(Tr)of tolerant genotypes declined faster owing to dehydration and recovered more sharply after rehydration than the same parameters in susceptible ones. Water stress caused a significant increase in leaf proline level and root xylem sap p H of both genotypes but tolerant genotypes recovered to pre-stress levels more quickly after rehydration. Tolerant genotypes also produced longer roots with higher dry mass than susceptible genotypes. We conclude that rapid perception and adjustment in response to soil drying and rewetting as well as the maintenance of relatively high Pn, %RWC, and root growth constitute the mechanisms by which drought-tolerant soybean genotypes cope with water stress.
文摘Soybean [<em>Glycine max</em> (L.) Merrill] seed yields in the northern United States may increase with the application of fertilizers;however Nitrogen (N) may decrease root nodulation. This study was conducted to understand the impact of N and sulfur (S) fertilization on soybean nodulation, plant, shoot and root biomass. Two cultivars were planted in experiments across ten site-years during 2015-2016. Plant observations took place at the V4 and R4 soybean growth stages. There were 41% more nodules per plant at R4 compared to V4 (38.3 vs 27.2 nodules, respectively). Cultivars responded differently to N and S fertilizer. The nodules per plant between the cultivars (30.3 vs 24.4) were different as well as the percent medium and large-sized nodules, which indicates the need to evaluate additional genotypes. Adding N decreased root nodulation (from 31.8 to 23.7 nodules per plant) and decreased nodule size but had no effect on plant, shoot or root mass. Averaged across N rates total plant mass was 2.26 and 11.36 g per plant at V4 and R4, respectively. Shoot mass, average across N rates was 1.77 and 9.65 g per plant at V4 and R4, respectively, and root mass, average across N rates was 0.49 and 1.71 g per plant at V4 and R4, respectively. Sulfur did not have an effect on nodules per plant but increased the percent medium size nodules at the R4 observation. There was no N by S interaction observed for nodule number, size of the nodules, and plant, root and shoot mass. As cultivars differed in their nodulation response to N and S, additional research would be helpful to screen other cultivars.
