Abstract:In this study,a phenylalanine ammonia-lyase (PAL) gene was cloned from Lamiophlomis rotata by the methods of Reverse-Transcription PCR and RACE.The full-length cDNA of L.rotata PAL (designated as LrPAL) was 2 298 bp,and contained a complete open reading frame (ORF) of 2 145 bp,which encoded 714 amino acid residues.Sequence analysis showed that it contains the typical PAL active site sequence (GTITASGDLVPLSYIA).Homology analysis indicated that the deduced LrPAL protein was highly homologous to other PAL proteins from different plant species.Phylogenetic tree analysis revealed that LrPAL had closer relationship with PALs from Labiatae plants than that from other plants.The results from Real-Time PCR indicated that the expression of LrPAL gene was the strongest in the leaves of L.rotata,and the least in shoots.As a result,the gene LrPAL which was cloned and characterized from L.rotata is a typical member of PAL family.The result indicated that LrPAL gene played a important role in the development of L.rotata plant.

Abstract:In this study,a Phi class GST named PtoGSTF4 was cloned from Populus tomentosa.PtoGSTF4 encodes a protein of 213 amino acid residues.RT-PCR revealed that PtoGSTF4 was a constitutively expressed gene that is expressed in stem,leaf and phloem of stem of P.tomentosa under normal growth condition,and H₂O₂ and atrazine stressed conditions.The recombinant PtoGSTF4 was expressed in E.coli and purified by Ni²⁺ sepharose affinity chromatography.PtoGSTF4 showed enzymatic activities towards substrates CDNB,NBD-Cl,NBC and Cum-OOH.Kinetic analysis found that the affinity of PtoGSTF4 to GSH was higher than that to CDNB.PtoGSTF4 had optimal pH ranging from 7.5~10.5 and optimal temperature ranging from 30 ℃~60 ℃.Our results indicated that PtoGSTF4 may play important roles in stress tolerance in P.tomentosa.

Abstract:BLAST searches of cotton EST database were performed using the AP2/ERF domain of the ERF-B3 subgroup transcription factors from Arabidopsis thaliana as a query sequence.Through the method of in silico cloning and RT-PCR,GhB301,an ERF-B3 subgroup transcription factor related to resistant Fusarium oxysporum f.sp.vasinfectum(Fov) was cloned from the roots of ‘Zhongmiansuo 12’ which was a high resistant cultivar to the infection of Fov.Sequence analysis indicated that the full length cDNA of GhB301 was 593 bp,with 384 bp ORF encoding 127 amino acids and a conserved AP2/ERF domain.qRT-PCR analysis indicated that,GhB301 gene highly expressed in roots and resistant cultivar after the treatment of Fov.The expression level of GhB301 also changed under the treatment of ET,SA,drought,low temperature and high salinity.The results suggested that GhB301 gene might participate in the response of plants to the pathogenic-bacteria,hormone and abiotic stresses.

Abstract:WRKY is the genes of a super transcription factors family that related to disease resistance.In order to reveal the role of WRKY40 gene in response to powdery mildew stress in apple.Malus domestica Borkh.cv.Fuji was used for gene cloning by reverse transcription PCR amplification by using specific primers.Quantitative real-time PCR was used in analyzing gene expression in tissues and in response to Podosphaera leucotricha and treatment of 1 mmol·L^-1 SA（salicylic acid）.(1)A 1 240 bp fragment including a 1 002 bp open reading frame to encode 334 amino acids was isolated.The amino acids sequence share 48.9% identity BLASTp to AtWRKY40,HvWRKY1/2/3 and others 4 sequences.It is a homologous gene of Arabidopsis AtWRKY40,and it is named as MdWRKY40b.Its GenBank accession is JX112907.(2)Gene expression indicated that MdWRKY40b expressed in root,stem,leaf and flower,with almost equally expression level in leaf,root and flower but very low level in stem.(3)It was clearly induced by P.leucotricha,and exogenous SA for a long times,with similar expression trends and the highest expression level time.The reason of Fuji apple extremely susceptible to powdery mildew maybe relate to the long-time and high expression of MdWRKY40b.

Abstract:Four species in genus Dioscorea (D.sinoparviflora C.T.Ting.,D.zingiberensis C.H Wright.,D.bulbifera L.,D.polystachya Turczaninow),22 taxa were amplified and sequenced the characteristic of psbA-trnH sequence.The length of D.sinoparviflora C.T.Ting.,D.zingiberensis C.H Wright.,D.bulbifera L.and D.polystachya Turczaninow fragments were 589~593 bp,575~599 bp,372 bp and 355~368 bp,respectively.According to the Bayesian phylogenetic tree,the psbA-trnH fragments couldn’t identify the intraspecific and interspecific species successfully.D.sinoparviflora C.T.Ting.and D.zingiberensis C.H Wright.are also not distinguishable.We suppose the evolution of Dioscorea species may be related with artificial domestication.D.bulbifera L.is close to cultivated Dioscorea species.

Abstract:In this study,two upland cotton lines TH₁ and TH₂ were employed.The anti-retroelement OVDREB2B in Orychophragmus vidaceus was integrated into plant expression vector and the transformation of cotton was conducted by pollen- tube pathway.The results of Kanamycin selection and molecular analysis showed that the transgenic cotton lines with OvDREB2B were obtained.T₁ and receptor plants were grown in greenhouse and treated by a serial of PEG-6000 osmotic potential at seedling stage.The results indicated that the obvious difference induced by different osmotic potential (0 and 0.5 MPa) was not observed in transgenic lines and control plants.However,the transgenic lines exposed to higher osmotic potential (0.8 and 1.1 MPa) displayed a significantly better resistance to drought.Meanwhile,the transgenic plants showed the significantly higher initial fluorescence,net photosynthetic rate,intercellular CO₂ concentration and transpiration rate than did the control plants under 1.1 Mpa condition for 96 h.Based on this fact,DREB2B gene resulted in the development of transgenic lines resistant to drouhgt stress.

Abstract:In order to explore the mechanism of drought resistance of upland cotton varieties,we chose and used drought-resistant upland cotton（Gossypium hirsutum L.）variety,‘Zhong H177’ and drought-sensitive variety,‘Zhong S9612’ as materials.Different water stress-induced proteome changes in different cotton（G.hirsutum L.）leaves at tri-leaf stage of seedlings under drought stress were analyzed by two-dimensional gel electrophoresis combined with mass spectrometry analysis.The results indicated that there had a big difference of protein components in different cotton leaves under drought stress.There were total 30 differentially expressed proteins discovered in ‘Zhong H177’ under drought stress,while 47 differentially expressed proteins discovered in ‘Zhong S9612’,only 11 protein spots appeared in ‘Zhong H177’,28 protein spots in ‘Zhong S9612’,8 protein spots had consistent expression,but 11 protein spots didn’t.43 differentially expressed proteins were identified and confirmed by MALDI-TOF-TOF MS,Functional classification analysis indicated that drought induced proteins were involved in photosynthesis,material and energy metabolism,stress tolerance protein,solute translocation and active oxygen scavenging.The difference in Rubisco activase and ATP synthase involved in energy metabolism is the largest,which could lay a foundation preliminarily for the research of drought resistance mechanism in upland cotton.

Abstract:The formation and development of sporoderm of the fern Pteris vittata L.(Pteridaceae) should be studied using light microscope (LM),scanning electron microscope (SEM) and transmission electron microscope (TEM).The results as follow:The spores are tetrahedral,round obtuse triangle in polar view,semi-circular or super semi-circular in equatorial view.The spores usually have tuberculate ornamentations and proximal ridge in the proximal surface,network ridges in the distal surface and the equatorial flange.The exospore,belonging to the Blechnum type,forms the outline of the spore ornamentations.The solid perispore is composed of two layers.The inner layer is thin and the outer layer is attached with small spherules.Based on the developmental features of the exospore and perispore,it is considered that Pteridaceae has close relationship with Hemionitidaceae and Ceratopteridaceae.The present results support the viewpoint that the Hemionitidaceae and Ceratopteridaceae are contained in the Pteridaceae.

Abstract:In order to make clear the regularity of tuberous root growth and amyloplast development in sweet potato,‘Xushu 22’ was used as the material in this study.The tuber growth and amyloplast development were studied by using resin semi-thin sections method.The experimental results showed that:(1)The primary growth of tuber with short duration time,the primary structure of tuber composed of epidermis,cortex and stele.The proportion of cortex on the cross section of tuber was bigger than that of stele.(2)The secondary growth of tuber started at 10 d after transplanting,the vascular cambium and the cork cambium formed in secondary growth.With the secondary growth,the parenchyma cells around the scattered vessel of secondary xylem dedifferentiated and formed accessory cambium by periclinal division.The vascular cambium,cork cambium and accessory cambium cooperated to make the tuber rapidly expanded.(3)The amyloplasts were first appeared in cortical cells as the secondary growth started,then appeared in large numbers in parenchyma cells which generated from secondary growth.The occurrence and development sequence of amyloplasts in tuber showed form outside to inside.(4)The starch granule in parenchyma cells had two types,the single starch granule and the compound starch granule.The parenchyma cells were mainly composed of compound starch granule in early stage of development,while parenchyma cells were mainly composed of single starch granule in later stage.The amyloplast with compound starch granule could divide and formed the amyloplast with single starch granule.(5)The starch could accumulate at whole period of tuber growth and the fastest accumulation rate appeared in middle period of tuber growth.

Abstract:We had a two-year investigation on flowering phonology,reproductive features and fruit set of Agapanthus praecox ssp.orientalis ‘Big Blue’ in Shanghai,China.We analyzed the influence of flowering phonology to reproduction from different levels.The results showed that:(1)The flowering span of population was early June to late July in Shanghai.Population duration was about 40 d and individual duration was about 14~31 d.Individual flower longevity was 2~3 d.Average flowering amplitude of two years was 6 flower·plant^-1·d^-1.Flowering percentage was 3.69%～4.87%.Average floral display was 11~17.(2)The census date of flowering phonology was late 6~9 d from 2007～2008.The curve of open flowers proportion showed two major peaks.The synchrony indices of two years were 0.663 and 0.695,it showed that the time of florescence overlap was long.The relative flowering intensity showed one major peak from 50%～70%.(3)The correlation analysis among onset,duration,flowers and fruit set showed marked relations.There were significantly negative correlations between onset and flowers,fruit set and duration.On the other hand,there were significantly positive correlations between flowers and fruit set,duration.The individual with an early starting date shows a longer duration than the individual with a later starting date.The individual with more flowers showed a longer duration than the individual with less flowers.The individual with a longer duration showed a higher fruit set than the individual with a shorter duration.At the same time,there were significantly negative correlations between the numbers of fruit from individual flower in the same inflorescence and individual flower blooming time.It showed that the sooner the individual flower open the more the fruit set.As a exotic plant,the similarity of flowering phonology within two years suggested that Agapanthus praecox ssp.orientalis ‘Big Blue’ could adapt to the environmental pressure and exhibited a steady flowering onset date and flower pattern.The longer florescence overlap and mass flowers may be regarded as an advantage to attract more pollinators and ensure its reproductive success.

Abstract:The ‘Bayuehong’ and ‘Hongxiangsu’ were taken as materials to study the changes of coloration,composition and content of anthocyanin,and related enzymes in sand pear (Pyrus pyrifolia) fruit skin under different cultivated regions and years.The result showed that:(1)The change rules of anthocyanin in ‘Bayuehong’ and ‘Hongxiangsu’ skin decided by the characteristics of cultivar,different cultivated region and years affected the absolute content of anthocyanin in the same cultivar,they could’t affect change trends of the composition and content of anthocyanin.However,the different change patterns and anthocyanin content observed in different cultivars.(2)The variation of skin color in red pear was consistent with the changes of cornflower-3-galactosidae content.The activities of UFGT(UDP-glucose:flavonoid 3-O-glucosyltransferase) and DFR(dihydroflavonol-4-reductase) increased with the fruit development and color deepenning,while the acitivity of PAL(phenylalanin ammonia lyase) decreased with the fruit development.(3)The correlation analysis revealed that a significant or very significant positive correlation between the content of anthocyanin and the activities of UFGT and DFR,wherease showed different correlation with PAL in different cultivars.The results indicated that UFGT and DFR are the important enzymes,which affect the coloration of red-skin sand pear.

Abstract:Resistance physiological indexes such as soluble proteins(SP),soluble sugars(SS),free proline(Pro),superoxide dismutase (SOD),peroxidase (POD),catalase (CAT) and malondialdehyde (MDA) of four species of samplings:Eucalyptus grandis (Eg),Cinnamomum pedunculatum (Cp),Simmondisa chinensis (Sc) and Camellia sinensis (Cs) were measured after fumigation of different levels of SO₂ in sealed environmental control chambers.Four levels of SO₂ treatments:control (natural concentration),M1 (0.5 mg·L^-1),M2 (1.5 mg·L^-1),and M3 (3.0 mg·L^-1) were set in the present study.The results showed that:(1)The order of the extent of injury of SO₂ on leaves is:Cp2 treatment significantly increased the concentrations of SP,SS,and Pro in leaves of Eg and Sc.There was no significant effect of SO₂ stress on SP and SS of Cp.The stimulated effect of SO₂ stress on Pro of Cp appeared only on 30 d of treatment.The responses of SS (no obvious effect),SP (significant depress effect),and Pro (significant stimulate effect) of Cs to SO₂ stress were different.(3)On the whole,SO₂ stress significantly increased the activities of antioxidant system enzymes (SOD,POD and CAT),and the content of MDA in leaves of Eg and Cp.There were different responses of SOD,POD,CAT and MDA to SO₂ stress of Sc.However,under SO₂ stress,the activities of antioxidant system enzyme activities and MDA content were overall declined significantly.(4)The maximum absorption of S element of Eg,Cp,Sc and Cs were 1.17,1.32,2.04,0.95 g·kg^-1,respectively.(5)The order of the comprehensive resistance calculated based on membership function was Cp>Sc>Eg>Cs,which was consistent with the results of injury of leaves.This study suggests that the antioxidant system enzymes play a important role in resistance of SO₂ stress for the four species of young trees and the extremely high level of basic POD activity in Cp may be one of the key mechanisms of resistance of SO₂ stress.

Abstract:LCO and TH17 paly an important role under abiotic stress.In order to explore the effects of LCO and TH17 on the yield and protective enzyme activities of oat under drought stress,we conducted this experiment by foliar-spraying the oat (Bayou 3) with 0.01 μmol/L concentrations of LCO and TH17 in growth cabinet with potting,to compare several changes of oat yield,osmotic regulation substances and protective enzyme activities.The results showed that:(1)The growth and development of oat were promoted under the normal water condition spraying LCO and TH17 and the yield of oats increased;under drought stress,LCO and TH17 could reduce the reduction of plant height,spike length,spike grain number,biological yield,grain weight per plant and the accumulation rate of dry materials of oats.In the seedling stage,spraying LCO and TH17 in the increasing rate of seedling stage single spike grain weight increased by 61.25% and 65.00% than that of SS_CK,respectively.(2)The LCO and TH17 could increase free proline content in elongation stage under drought stress,and increased by 27.19% and 41.00% than that of SS_CK,respectively.The highest increase rate of soluble sugar content was in the heading stage,it increased by 61.43% and 112.54% than that of SS_CK,respectively.The highest increase rate of soluble protein content was in seedling stage,and increased by 9.58% and 13.80% than that of SS_CK,respectively.(3)Under drought stress,the SOD and POD activities increased after spaying LCO and TH17 in heading stage and the CAT activity in the elongation stage.(4)Under drought stress,the LCO and TH17 could reduce the amplitude of the highest relative conductivity and MDA content in seedling stage,decreaesd by 17.61%,36.67%,43.43%,30.28% than that of SS_CK,respectively.In summary,the effects of spraying LCO and TH17 in seedling stage was the largest;the LCO and TH17 can increase contents of osmotic adjustment substances and activities of protective enzymes in oat under drought stress.

Abstract:Using the Carpinus betulus annual seedlings as experimental material,we studied the physiological and biochemical responses of C.betulus seedlings under soil drought stress with five different soil content levels.The result showed:(1)With drought stress increasing,the damage of plant gradually increased,and external morphology characteristics of water shortage were distinct.Relative water content and total chlorophyll content decreased as the drought stress increasing and the ranges were greater as the drought degrees became higher;(2)The variation trend in SOD activity,POD activity,soluble sugar content and soluble protein content was increased at first then decreased;(3)Along with the period of drought stress continued,MDA content and relative conductivity increased and reached a maximum at last.It was resulted that C.betulus seedlings improved the characteristics of resistance to soil drought by increasing the activities of protective enzymes and osmatic adjustment substances in the short time and mild(field water holding capacity of 60%),moderate(field water holding capacity of 45%) stress,but under severe stress(field water holding capacity of 30%),the self regulation ability was affected and extreme drought stress(field water holding capacity of 15%) caused some damage to the plants.It indicated that C.betulus has some drought-resistant properties to drought condition,and it can be widely used in landscape application.

Abstract:We aimed to investigate water response by assessing physiological photosynthetic parameters of Salix matsudana growing on the Shell Ridge Islands,and to determine their moisture adaptability in a sandy habitat formed from seashells.We measured net photosynthetic rate,light response,chlorophyll content,leaf water potential and other parameters of S.matsudana grown in soils with different moisture contents,simulating the natural moisture gradient of the shell sand habitat.We found that:(1)A rectangular hyperbolic correction model best simulates the light response of S.matsudana leaves (R²>0.96).High photosynthetic capacity is maintained at 50.1%～94.4% soil relative water content (RWC) under optimal light intensities ranging from 800～1 600 μmol·m^-2·s^-1.(2)Photosynthetic light response of S.matsudana leaves show a certain threshold response to soil moisture content.Net photosynthetic rate,light saturation point,apparent quantum yield (AQY) and the maximum net photosynthetic rate all demonstrate optimal capacity at medium soil moisture content.Soil moisture content can significantly affect the light use efficiency and the light ecological amplitude of the plant.Under drought or waterlogged stress conditions,the light compensation point of S.matsudana increases,while its light saturation point decreases,light ecological amplitude narrows and light use efficiency decreases.(3)Instantaneous water use efficiency and potential water use efficiency of S.matsudana leaves reach their maximum values when RWC is 45.7% and 40.6%,respectively.Thus,we conclude that moderate drought stress can significantly increase water use efficiency of S.matsudana growing in a shell sand habitat.(4)Both drought and waterlog stress can significantly lower chlorophyll content and leaf water potential.The chlorophyll content and leaf water potential reach their maximum values when RWC is 58.9% and 50.1%,respectively.Our study shows that net photosynthetic rate,photosynthetic light response parameters,water use efficiency,chlorophyll content and leaf water potential of S.matsudana living in a shell sand habitat have distinct threshold responses correlated with soil moisture.In conclusion,S.matsudana is found to be a species with wide water ecological amplitude,which is resistant to high soil moisture content and susceptible to drought.

Abstract:The aim of the study is to investigate the effect of He-Ne laser pretreatment of wheat seeds on the seedlings resistance to cadmium stress.The results showed that 150 μmol/L Cd treatment significantly reduced plant height,root length,shoot dry weight,root dry weight,ascorbate acid (AsA) and glutathione (GSH) contents,the activities of superoxide dismutase (SOD),peroxidase (POD),catalase (CAT),ascorbate peroxidase (APX),enhanced the contents of malondialdehyde (MDA),hydrogen peroxide (H₂O₂) and the rate of superoxide radical (O^-·₂) generation in the wheat seedlings when compared with the control.However,seeds with He-Ne laser pretreatment for 5 min conferred tolerance to cadmium stress in wheat seedlings by decreasing the contents of MDA and H₂O₂,the rate of O^-·₂ generation and increasing the activities of SOD,POD,CAT,APX and AsA,GSH contents.These results suggest that those changes in MDA,O^-·₂,H₂O₂,anti-oxidative enzymes,and antioxidative compounds are responsible for the enhance cadmium stress resistance observed in the experiments.The results also show that the laser have a positive physiological effect on the growth of cadmium stressed seedlings.

Abstract:Hydroponics experiments were conducted to study the effects of atrazine stress (5,10,20,40 mg·L^-1) on O^-·₂ production rate,H₂O₂ content,activities of superoxide dismutase (SOD),catalase (CAT) and peroxidase (POD),malondialdehyde (MDA) content and plasma membrane permeability in leaves of Pennisetum hydridum,and the resistance and physiological mechanisms of P.hydridum to atrazine stress were discussed.The results indicated,plant samples were collected after 5,10,15 and 20 days.(1)Low level of atrazine stress (5,10 mg·L^-1) elevated O^-·₂ production rate and CAT activity in leaves of P.hydridum,and decreased H₂O₂ content,the activities of SOD and POD.With prolonging of cultivation time,the above indexes have returned to normal levels,but high level of atrazine stress (40 mg·L^-1) decreased H₂O₂ content,the activities of SOD,CAT and POD in leaves of P.hydridum continuously.(2)After 10 days,MDA content in leaves of P.hydridum treated by all levels of atrazine stress began to increasing.With the increase of atrazine concentration,the increasing amplitude of MDA content was significantly increased.All levels of atrazine stress showed no significant effects on relative permeability of plasma membrane.Therefore,P.hydridum probably regulates the activities of protective enzymes by signaling molecules such as reactive oxygen species,which could alleviate the injury caused by atrazine,and thus P.hydridum showed strong resistance to low level of atrazine stress (5,10 mg·L^-1).

Abstract:By contrast natural light fruit,the fruit of Ziziphus jujuba Mill.cv.lingwuchangzao were treated with shielding light at full flowering stage.The fruit growth index,chlorophyll content,enzyme activities of the sucrose metabolism and sugar content were measured to study the effects of photosynthesis on accumulation of fruit sugar and the content of polysaccharide and total sugar.The result showed that:(1)The weight and fruit volume of single fruit and content of chlorophyll reduced after shielding light treatment.(2)The activities of fruit invertase,sucrose phosphate synthase and the decomposition enzyme of sucrose synthase increased but the activities of the synthetic enzyme of sucrose synthase reduced with the different extent of shielding light treatment.(3)Shielding light treatment mainly affected sugar content in stages of color changing and ripe stage,but little effect on initial period of fruit development.In conclusion,the formation of polysaccharide in fruit had the certain relations to normal illumination,but the accumulation of total sugar in fruit had close relations to illumination.To sum up,shielding light treatment affected sugar metabolism and accumulation by influence enzyme activities of the sucrose metabolism in developmental fruit.

Abstract:Photosynthetical gas exchange and chlorophyll fluorescence are important measures of plant adaptation to environments.However,their temporal variation during plant growth is still not clear.Our objective is to elucidate how they change as the plant grows.A local lucerne (Medicago sativa L.cv.Longdong) was chosen and gas exchange,chlorophyll fluorescence,chlorophyll content,sucrose content and related synthase activities,and biomass were measured at different growth stages of each cut in a glass house experiment.(1)Dry matter of the aboveground part and leaf increased as lucerne grew in each cut,while the average dry matter increment per day increased in the anterior two cuts and first increased and then decreased in the third cut,appearing some “S” type of growth.(2)Net photosynthetic rate (P_n),stomatal conductance and carboxylation efficiency decreased as lucerne grew in each cut,while intercellular CO₂ concentration did oppositely,and water use efficiency and stomata limitation to P_n decreased in the first cut but increased in the latter two cuts.(3)Sucrose content increased,while the activities of sucrose synthase and sucrose phosphate synthase did not change significantly.(4)Chlorophyll contents,including chlorophyll a,b and both,increased as lucerne grew in each cut.Chlorophyll fluorescence changed obviously only at the beginning in the first cut,and maintained stable in the rest cuts.Conclusively,lucerne showed obvious but different temporal variations in gas exchange and chlorophyll fluorescence in response to the environmental factors during stand growth.

Abstract:The photosynthetic and physiological responses of Jiangxi Yanshan red bud taro (Colocasia esculenta L.Schott var.cormosus cv.Hongyayu) transplantating seedlings under 50,100,150,200,250 mmol·L^-1 and 0 (CK) of salt stress were studied using its transplantation seedlings.The results showed that:(1)The biomass and root shoot ratio of seedling increased under low salt stress (50 mmol·L^-1 ),and inhibited under high salt stress (100～250 mmol·L^-1).(2)Under low salt stress,the photosynthetic rate (P_n),stomatal conductance (G_s),stomatal limitation value (L_s),water use efficiency (WUE) and instantaneous carboxylation efficiency (CUE) of seedling significantly increased compared with the control (0 mmol·L^-1),its intercellular CO₂ concentration (C_i) decreased significantly compared with the control,and its transpiration rate (T_r) had no significant difference compared with the control.Under the high salt stress,P_n,L_s,WUE,CUE,G_s and T_r of seedling decreased significantly and its C_i increased significantly compared with the control.(3)Under low salt stress,the maximal fluorescence (F_m),photochemical quenching coefficient (F_v/F₀) and photochemical quenching coefficient (q_P) of seedling significantly increased compared with the control;initial fluorescence (F₀) decreased significantly compared with the control.PSⅡ maximal photochemical efficiency (F_v/F_m),actual photochemical efficiency of PSⅡ (Φ_PSⅡ),open PSⅡ reaction center capture the excitation energy efficiency (F_v′/F_m′) and non photochemical quenching coefficient (NPQ) had no significant difference compared with the control.Under the high salt stress,F₀,F_m,F_v/F_m,F_v/F₀,Φ_PSⅡ,F_v′/F_m′ and q_P of seedling decreased significantly compared with the control;NPQ increased significantly compared with the control.(4)Under salt stresses,soluble protein content,peroxidase,superoxide dismutase and catalase activities of seedling increased first and then decreased compared with the control,reaching the peak at 50 mmol·L^-1,while its content of total soluble sugar and proline were increased significantly compared with the control;its MDA content and plasma membrane permeability had no significant change at 0～50 mmol·L^-1 and began to increase significantly from 100 mmol·L^-1;its chlorophyll content and root activity had no significant change at 0～50 mmol·L^-1 and began to decrease significantly from 100 mmol·L^-1.The study indicated that Jiangxi Yanshan red bud taro transplantation seedlings salt tolerance threshold was 50 mmol·L^-1,which could promote the increase of the soluble protein content,the activities of peroxidase,superoxide dismutase and catalase;maintain the membrane permeability,the chlorophyll content and root activity;increase PSⅡ maximal photochemical efficiency;improve the PSⅡ electronic transfer activity,maintain actual photochemical efficiency of PSⅡ,waste excess light energy as heat by the effective starting non radiative heat energy dissipation mechanisms,thus protect the photosynthetic apparatus,and ultimately enhance net photosynthetic rate and increase the biomass.

Abstract:In order to clarify the regular pattern which Periploca sepium Bunge responds for the salt stress and investigate the optimum saline concentration and light condition for the growth of P.sepium Bunge,we measured the light response of photosynthetic parameters,such as net photosynthetic rate(P_n),transpiration rate(T_r),stomatal conductance(G_s),water use efficiency (WUE) and light use efficiency(LUE),to P.sepium Bunge in different saline concentrations with CID portable photosynthesis system.The results show:(1)The LCP of P.sepium Bunge varies from 21.89～65.05 μmol·m^-2·s^-1 under different of saline concentrations.It means that P.sepium Bunge is between the negative and positive plants.With the different of soil salinity,the photosynthesis of P.sepium Bunge for illumination intensity shows some adaptability and plasticity.The photo assimilation ability of P.sepium Bunge is stronger under the 50 mmol·L^-1 of saline concentration.The accumulation of dry matter is enhanced and the plants show salt resistance to a certain extent.(2)The light salt stress less than 50 mmol·L^-1 can improve the P_n,G_s,WUE and LUE of P.sepium Bunge leaves,and the salt stress has inhibitory effect to T_r,and the inhibitory effect is positive related with the saline concentration.(3)In order to maintain the normal growth,the fitting saline concentration of soil is less than 50 mmol·L^-1,and the optimum PAR is between 1 000～2 000 μmol·m^-2·s^-1,and the illumination intensity to maintain the high WUE and LUE is separately 800 μmol·m^-2·s^-1 and 100 μmol·m^-2·s^-1.

Abstract:Variations of age or developmental stage could influence plants’ ability for drought resistance.Ten drought-resistance physiological characteristics of Juniperus sabina at three ages were measured in this paper.Results indicated that:(1)The values of water-losing rate were already significantly different among different seedling ages under the condition of normal water supply,so were relative permeability of membrane and RuBP activity.But there was no significantly difference on relative water deficiencies (RWD),stomatal conductance(G_s),net photosynthesis (P_n) rate etc.among these three seedling ages.(2)Under water stress,there was still no significant difference on RWD and G_s among these three seedling ages all along.The P_n,transpiration rate(T_r),water use efficiency (WUE)and intercellular carbon dioxide concentration (C_i) of these three seeding ages were significantly different when the SWC is 6.78%.As the SWC got down to 4.52%,significant difference appears among these three ages on their light-use efficiency.(3)Comparison of these three age-groups showed that P_n,RuBP activity and light-use efficiency of the 5-year old seedlings were significantly lower than that of the 1-year old seedlings’ under water stress.Nevertheless,C_i,magnitude of the declines in G_s and T_r,and magnitude of the increase in WUE of the 5-year old seedlings were significantly higher than that of the 1 and 3-year old seedlings’.Thus it can be seen that seedlings’ responses to drought stress may differ between different seeding ages.The stability of the drought-resistance indicators to age were different.The 1-year old seedlings have more life vitality than 5-year old seedlings and the 5-year old seedlings were much more adaptable to water stress.We should better choose the materials at the same age during drought resistance appraisal ,and the sensitivity and stability of indicators to seedlings’ age must be considered.

Abstract:Tamarix ramosissima community is facing a serious degradation at southern fringe of the Taklimakan Desert.Deficient water conditions impose restrictions on seedlings establishment and survival of T.ramosissima.In order to study root biomass accumulation and spatial distribution of T.ramosissima seedlings to provide suggestions for rehabilitating degraded ecosystem,we set up three irrigation treatments:treatment A (no irrigation),treatment B (moderate irrigation) and treatment C (sufficient irrigation) at southern fringe of the Taklimakan Desert.Result showed that:(1)Irrigation significantly affected root growth and spatial distribution.The root biomass accumulation increased gradually with increased irrigation and the biggest growth rate at the end of growth season (October).Meanwhile the proportion of fine roots also increased from 20.5% to 29.8%,which improved the ability of absorbing moisture and nutrient from soil significantly.(2)Under drought stress (treatment A),the root length of seedlings was the longest,while the horizontal distribution of root was restricted.Under moderate irrigation (treatment B),the root biomass was more than that of treatment A but less than that of treatment C;the root level distribution of T.ramosissima seedlings:treatment AT.ramosissima root depth was shallow,but level distributing of root was most expander in order to use the shallow soil resources more effectively.(3)The most roots are distributed between 0～40 cm of the soil and the wetter,the centralized trend is more obvious.Root biomass was decreasing with the increase of soil depth,so had the same change of root length density of fine roots,but the change of specific root length of fine roots was unconspicuous which could be related with microcosmic environment of soil.The results showed that irrigation had a significant impact on root growth and distribution of T.ramosissima seedlings.Under treatment C(sufficient irrigation),the weight of root biomass is the biggest and spatial-temporal distribution is the largest compare with the others,which indicated treatment C(sufficient irrigation) is conductive to root normal growth and reasonable distribution of T.ramosissima seedlings.

Abstract:In order to build foundation for spruce identification in seedling stage and evaluation of adaptability,one year old seedlings from seven species of Picea were selected to study the interspecific and intraspecific genetic variation of basic needle morphological characters.The results showed that:(1)Needle length,needle width,needle length/width,fresh weight,dry weight and moisture content in winter differed significantly among species.There were abundant genetic variations within and among the seven species.(2)The coefficient of variation of needle characters as follows:the fresh weight (47.65%)>dry weight (40.94%)>needle width (24.98%)>needle length (22.39%)>needle width/length (21.32%)>moisture content in winter (12.75%),the coefficient of variation of fresh weight was the largest,and the moisture content in winter was the most stable character.(3)To white spruce,the intraspecific variation coefficient of fresh weight and dry weight was the largest,was 50.85% and 38.01%,respectively.The coefficient variation of needle moisture content in winter of blue spruce was the smallest (2.11%).(4)There were very significant correlations among the six indices mentioned above except for needle length/width with fresh weight,dry weight and moisture content in winter.The relationship of each needle character and height,seedling height growth were significant or very significant excepting needle length/width.(5)The determination coefficients of needle dry weight and needle length,needle width were between 0.793～0.993.Seven species could be divided into three categories according to the needle length,and their seedlings could be identified and selected according to needle length,width and length/width,fresh weight,color and stomatal band.

Abstract:Based on field data,we established 100 quadrats within fourteen tree species in Taiyue Mountain of Shanxi.We analyzed interspecific segregation by using ArcView GIS software and the nearest neighbor method,interspecific segregation was studied with an N×N nearest-neighbor contingency table,a 2×2 nearest-neighbor contingency sub-table,and Pielou coefficient of segregation(S).According to their adapt ability to the environment and relationships between plants and environment,assisting in principal components analysis,the 14 species divided into three ecological species groups (ESG).The results showed:(1)Most of the species pairs are randomly segregated (74.73%),some species pairs are positively segregated (23.07%),and only a few species pairs are negatively segregated (2.20%).(2)There are some differences among different species in the interspecific segregation of all species.The Ulmus lamellosa in the communities tended to be randomly segregated with other species.Positive segregation appeared among dominant species,probably because of their stronger competitive vigor.For example,Carpinus cordata,Acer elegantulum and Populus davidiana are tended to be positively segregated each other.Negative segregation appeared among companion species in the communities,such as Carpinus turczaninowii,Acer grosseri,Koelreuteria paniculata and Acer ginnala.(3)The interspecific segregation is related to the heterogeneity in the communities,in that segregation often occurs between two species which have different habitat requirements;while the aggregation often appears between two species which have same or similar environmentally requirements.(4)In Ulmus lamellosa communities,the 14 species divided into three ecological species groups.On the whole,the 14 species we studied overlapped in distribution and were characterized by overall non-segregation.The interspecific relationships based on different species are adapted and their biological requirements may be one of the mechanisms which allow these species to stably coexist in the U.lamellosa community of the Taiyue Mountain in Shanxi.

Abstract:Six types of 25 years stand density(3 400 plants/hm²,2 900 plants/hm²,2 600 plants/hm²,2 300 plants/hm²,2 150 plants/hm² and 1 750 plants/hm²) were selected,and the law of importance values,species richness,species diversity index,evenness index with stand density were analyzed to study the relationship between stand density and plant diversity of under growth of Picea crassifolia plantation in Baoku Forest farm at Datong County of Qinghai Province.The aim of this paper was to verify an appropriate stand density that could improve plants diversity and maintain the stability of plantation ecosystem.The result showed that:(1)There were 60 vascular plants and one nonvascular plant in 45 families and 29 genera of under growth in P.crassifolia in the study area.(2)Stand density had a significant influence on dominant plants in shrub layer,but the influence was not obvious in herb layer;(3)There was a positive correlation between stand diversity and species richness index,Shannon-Wiener index and Alatalo index in shrub layer,and the correlation coefficients were 0.688,0.937,0.762,respectively.With respect to herb layer,the correlation between them was also obvious,and the correlation coefficients were 0.679,0.870,0.505,respectively.(4)As stand density increased,plants diversity decreased firstly,then increased and finally decreased.The research suggested that the response of plant diversity of understory vegetation to stand density was non-synchronous.When density arrived at 2 600 hm²,the understory plant diversity reached the maximum,which indicated that the density was more appropriate for growth and development of understory vegetation,and can contribute to an increase in forest diversity.

Abstract:(1)An endophytic fungus DZ05 isolated from medicinal plants Eucommia ulmoides was identified as Paecilomyces lilacinus based on its morphological characteristics and internal transcribed spacer (ITS) sequence.After being cultured in PDA medium for 3 days,DZ05 can secrete antimicrobial metabolites.(2)The ethyl acetate extraction of the fermentation broth exhibited significant inhibitory activity against 6 test bacteria and 9 phytopathogens,especially against Botrytis cinerea,Fulvia fulva and Colletotrichum gloeosporioides with diameters above 40 mm.The result indicated that the extraction of DZ05 has broad spectrum antimicrobial activity and may have potential application in the prevention and treatment of these phytopathogens.

Abstract:One genus and three species of plant are recorded to Shaanxi,China for the first time.The newly recorded genus is Fatoua Gaudichaud-Beaupré (Moraceae).The newly recorded species are Fatoua villosa (Thunberg) Nakai,Leonurus chaituroides C.Y.Wu & H.W.Li and Codonopsis lanceolata (Siebold & Zuccarini) Trautvetter.It not only has important significance for supplementing the plant resource and riching the plant flora of Shaanxi,but also reflects the special plant types of Jinsixia Grand Canyon in the Qinling Mountains.

Abstract:Rab proteins are one member of the Ras superfamily of small GTP-binding proteins.Phylogenetic analysis of amino acid sequence of Rab proteins indicate there are eight subfamilies in plants,such as RabA,RabB,RabC,RabD,RabE,RabF,RabG and RabH.The different Rab proteins are generally localized to the cytosolic face of specific intracellular membranes,where they act as key regulators of vesicular trafficking pathways.Rab proteins have highly conserved structural domains and greatly functional diversity.They have very important roles in cell proliferation,apical dominance,pollen tube growth,nodule development,and in response to both biotic and abiotic stresses.Therefore,this paper mainly summarized the structure characteristics and the function of Rab proteins in plants.

Abstract:Annexins are homologous,soluble and multifunctional proteins capable of Ca²⁺-dependent and Ca²⁺-independent binding to or insert into the membranes.Annexins exist in some prokaryotes and all eukaryotic phyla and always represent in high organisms as multiple gene family.The structure of plant annexins has only 1 or 2 repeats which are highly conserved (usually the first and the fourth).Functionally,plant annexins have the abilities of binding to cytoskeleton,hydrolysing ATP and GTP,acting as peroxidases or cation channels in response to abiotic stresses such as salinity,drought,high and low temperature,metal stress and wounding and biotic stresses such as fungi and pests.Annexins are expressed in a majority of plant organs and throughout the whole life cycle and varied with the body growth,development and environment change and play an important role in resistance to stress.In this paper,the known structure and function of plant annexins,especially the relationship between annexins and plant stress response were systematically summarized so as to offer an oriented suggestion for researches in plant annexins and stress resistance.