摘要：
Exotic pine trees are often introduced to novel places worldwide. How exotic pines interact with local microbial communities, such as symbiotic ectomycorrhizal (ECM) fungi, during early establishment compared to interactions by their native counterparts remains to be examined in detail. In this study, native masson pine (Pinus massoniana) and exotic slash pine (Pinus elliottii) seedlings were grown in field-collected soil cores. ECM root tips were collected 3- and 6-months after planting and fungi were identified using high-throughput sequencing. We found that host identity was a key factor determining ECM fungal community assembly after 3-months: native pines associated with Rhizopogon while exotic pines associated primarily with ECM generalists. After 6-months growth, however, ECM fungal communities in native and exotic pines were both dominated by Rhizopogon species. We also found that host selections of several pioneer ECM fungi shared by both native and exotic pines may facilitate an exotic pine's establishment. These findings indicate that more attention should be paid to ECM fungal community shuffling by exotic trees during early establishment and, in turn, the influence of the potential changes in ECM fungal communities on local forest ecosystems.
作者机构：
[Wang, Jiaolong; Yan, Wende; Ning, Chen] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;[Yan, Wende; Ning, Chen; Chen, Xiaoyong] Natl Engn Lab Appl Technol Forestry & Ecol South, Changsha 410004, Peoples R China.;[Gsell, Timothy; Chen, Xiaoyong] Governors State Univ, Coll Arts & Sci, University Pk, IL 60484 USA.
通讯机构：
[Yan, Wende] C;[Yan, Wende] N;[Chen, Xiaoyong] G;Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;Natl Engn Lab Appl Technol Forestry & Ecol South, Changsha 410004, Peoples R China.
关键词：
Polycyclic aromatic hydrocarbons;Artificial root exudates;Koelreuteria Paniculata;Phenanthrene;Bacterial community structure
摘要：
Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants that represent a serious threat to the health of humans and ecosystems. The effects of plant root and artificial root exudates (ARE) on the biodegradation of phenanthrene (PHE) and their impact on soil bacterial community structure was the focus of this work using four treatments for 180 days. Treatments included; control treatment (CK), low concentration of ARE (AREL), high concentration of ARE (AREH), and planting Koelreuteria paniculata saplings (KOE). The diversity and composition of soil bacterial community were analyzed using highthroughput sequencing. The results showed that KOE treatments had the most significant effect on the biodegradation of PHE compared to controls. ARE treatments had the similar effects on the biodegradation of PHE in soil with high efficiency in AREH than AREL. Both KOE and ARE treatments reduced diversity of bacterial community but increased the abundance of PAHs degrading bacterial populations within representative phyla, including Proteobacteria and Firmicutes. During the study, the total bacterial OTUs showed the number of unique genus types initially increased, then lowered in the later stages of the incubation process. Specific bacterial populations enriched by the treatments and supported by the exudates seemed to determine the biodegradation of PHE and not the overall bacterial diversity. (C) 2020 Elsevier Ltd. All rights reserved.
摘要：
Phellodendron chinense Schneid is an important Chinese herb with berberine and phellodendrine in stems and leaves, but with little information available on in vitro culture of this species. Disinfection of explants in 75% alcohol for 45 s, sterilization in 0.1% HgCl2 for 20 min, and submersion in 1.0 mol L-1 gibberellin3 (GA(3)) solution for 24 h was the optimal condition for seed germination. Murashige and Skoog's (MS) medium supplemented with 2.0 mg L-1 6-benzylaminopurine (6-BA) in combination with 1.5 mg L-1 1-naphthylacetic acid (NAA) was optimal for callus induction. MS medium supplemented with 2.0 mg L-1 6-BA was the appropriate medium for induction of adventitious shoots, and 1/2MS medium supplemented with 2.0 mg L-1 indole-3-butytric acid (IBA) and 0.5% active carbon was the optimal medium for root induction. The 15-d survival rate of regenerated plantlets after transplanting to basins containing perlite and peat moss (1:4) was greater than 80%, and the berberine and phellodendrine accumulation was lower in callus compared with regenerated plantlets. The establishment of highly efficient regeneration system provides technical support for genetic breeding of Phellodendron chinense Schneid.
作者机构：
[闫文德; 颜成正] College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, China;[郑文革] Beijing General Station of Soil and Water ConservationBeijing 100036, China;[王忠诚; 贾剑波] College of Forestry, Central South University of Forestry and Technology, Changsha, 410004, China;[贾国栋] College of Water and Soil Conservation, Beijing Forestry UniversityBeijing 100083, China
关键词：
冠层气孔导度;土壤含水量;液流密度;水汽压亏缺
摘要：
建立了不同控水条件下(无降水、一半降水、自然降水和二倍降水)的侧柏样地,于2016年8月—2017年8月监测了样地土壤含水量(SWC)、降水量、液流密度(Js)、叶面积指数(LAI)和水汽压亏缺(VPD)等因子,分析SWC对侧柏冠层气孔导度(gs)的影响。结果表明: 一半、自然和二倍降水样地的SWC与降水量呈正相关,SWC变化范围分别为4.9%～16.0%、7.2%～22.9%、7.4%～29.6%,无降水样地的SWC在8—10月下降50%;7月的日gs在14:00达到峰值(166.64 mmol·m-2·s-1),显著高于其他月份,且出现双峰现象, 1月的日gs在12:00达到峰值(54.1 mmol·m-2·s-1);3个降水条件下,侧柏gs与SWC呈负二次相关关系,且gs达到峰值,对应的SWC分别为8.5%、12.5%和18.5%,均趋近于年平均SWC。不同控水样地内侧柏gs对VPD的敏感性(δ)/参比冠层气孔导度(gsref)均≥0.6,表明不同控水条件下土壤水分状况较适合侧柏蒸腾用水的需求。当SWC在3.7%～7.5%时,δ和gsref值迅速增大,说明气孔调节能力更好,植物气孔对VPD的响应更敏感;当SWC上升到11%时,SWC变化对gsref和gs对VPD响应敏感性的影响不显著。可能存在侧柏产生适应状态的SWC阈值,植物体在自身的生命活动中关闭或减小气孔开度,降低叶片水势以适应过高的VPD,保护植物不会引起过度蒸腾,从而对蒸腾的调控更加有效。.A water-controlled experiment with four treatments (no rain, half raining, natural raining and double raining) was carried out in a Platycladus orientalis forest. The factors including soil water content (SWC), precipitation, sap flow density (Js), leaf area index (LAI), vapor pressure deficit (VPD) were monitored during August 2016 to August 2017. We further analyzed the response of canopy stomatal conductance (gs) to changes of SWC. The results showed that the SWC of plots (half, natural and double raining) showed a positive correlation with precipitation, and the range of SWC was 4.9%-16.0%, 7.2%-22.9%, 7.4%-29.6%, respectively. The SWC in the plot with no rain decreased by 50% from August to October. The daily gs reached a peak of 166.64 mmol·m-2·s-1 at 14:00 in July, which was significantly higher than other months. A bimodal phenomenon occurred. The daily gs reached a peak of 54.1 mmol·m-2·s-1 at 12:00 in January. Under the three rain plots, diurnal variation of gs and SWC showed a negative quadratic correlation. The SWC corresponding to the peak of gs was 8.5%, 12.5% and 18.5%, respectively, close to the annual average SWC. Sensitivity (δ) of gs to VPD /reference canopy stomatal conductance (gsref) was more than or equal to 0.6 in different water-controlled plots, indicating that soil water condition was more suitable for water demand of P. orientalis. When SWC was between 3.7% and 7.5%, the δ and gsref increased rapidly, indicating that stomata had better regulation ability, and that plant stomata was more sensitive to VPD. When SWC increased to 11%, SWC alteration did not affect the response sensitivity of gsrefand gs to VPD. There might be a SWC threshold value for the adaptation of P. orientalis. By closing or reducing stomatal aperture, leaf water potential decreased, P. orientalis could adapt to excessive VPD and avoid excessive transpiration, which was more effective in regulating transpiration.
作者：
Ning, Chen*;Xiang, Wenhua;Mueller, Gregory M.;Egerton-Warburton, Louise M.;Yan, Wende;...
期刊：
Plant and Soil,2020年446(1-2):179-193 ISSN：0032-079X
通讯作者：
Ning, Chen
作者机构：
[Liu, Shuguang; Xiang, Wenhua; Yan, Wende; Ning, Chen] Cent South Univ Forestry & Technol, Fac Life Sci & Technol, 498 Southern Shaoshan Rd, Changsha 410004, Peoples R China.;[Ning, Chen] Northwestern Univ, Program Plant Biol & Conservat, Evanston, IL 60208 USA.;[Mueller, Gregory M.; Egerton-Warburton, Louise M.] Chicago Bot Garden, Chicago, IL 60022 USA.
通讯机构：
[Ning, Chen] C;Cent South Univ Forestry & Technol, Fac Life Sci & Technol, 498 Southern Shaoshan Rd, Changsha 410004, Peoples R China.
关键词：
Community structure and function;Ectomycorrhizal fungi;Extracellular enzyme;Exotic pine;Rhizopogon;Russula
摘要：
Atypical dual-specific phosphatases (PFA-DSP) is a kind of special phosphatase in plants, and play key roles in physiological processes. OsPFA-DSP2 is a member of PFA-DSP family, and negatively regulates Magnaporthe grisea responses in when overexpressed in rice. Whereas, their activity and function response to bacterial pathogen stress are still unknown. The results showed that OsPFA-DSP2 was a tyrosine-specific phosphatase, and its phosphatase activity was regulated by redox condition. The overexpressing OX13/21 lines were sensitive to Xanthomonas oryzae pv. Oryzae (Xoo) and enhanced the expression levels of OsCEBiP in leaves, but showed little difference on the H2O2 production compared with control. Interestingly, OsPFA-DSP2 physically interacted with OsMAPK9 in vitro. These findings indicated that OsPFA-DSP2 was a tyrosine-specific phosphatase that negatively regulates Xoo response in overexpressing rice lines, which may execute through the mitogen-activated protein kinase (MAPK) signaling pathway.
关键词：
Leaf area index;Leaf title angle;Canopy openness index;Conifer;Chinese fir;LAI-2200C
摘要：
It has been generally accepted that different silvicultural practices affect the forest canopy morphology and structure. During forest establishment, many natural sites were converted to coniferous plantations in southern China. Retention of the canopy during stand conversion may be desirable to promote ecological function and meet conservation objectives. We tested the impact of planting density, foliar nitrogen and soil chemical properties on the canopy development of Chinese fir (Cunninghamia lanceolata) mid-age monoculture stands. Low density (1450 trees hm(-2) with planting spacing of 2.36 x 2.36 m), intermediate-density (2460 trees hm(-2) with planting spacing of 1.83 x 1.83 m) and high density (3950 trees hm(-2) with planting spacing of 1.44 x 1.44 m) stands were selected in Xinkou forest plantations in Sanming City, China. Canopy characteristics such as leaf area index (LAI), mean tilt angle of the leaf (MTA) and average canopy openness index (DIFN) were measured. Measurements were taken using LAI-2200 PCA. The results illustrated that stand density was the primal factor responsible in canopy structuring while soil chemical properties seem to play a secondary role for canopy dynamics. LAI increased from 3.974 m(2) m(-2) to 5.072 m(2) m(-2) and MTA increases from 34.8 degrees to 48.7 degrees as the stand density increased while the DIFN decreased from 0.1542 to 0.0902 with the increasing stand density but it was no significantly different in intermediate and high-density stands. Additionally, LAI and MTA were positively correlated to foliar nitrogen while the DIFN was negatively correlated. In general, soil available nitrogen, available phosphorus and soil pH were not significant to canopy parameters. The results presented provide guiding principles about the canopy dynamics distribution in varying stand densities from LICOR measurements in mid-age Chinese fir monoculture. Furthermore, this provides a base to study canopy dynamics at mature stage forests because of more senescence activities. (C) 2020 The Author(s). Published by Elsevier B.V.
期刊：
Ecology and Evolution,2019年9(9):5338-5347 ISSN：2045-7758
通讯作者：
Deng, Xiangwen
作者机构：
[Ouyang, Shuai; Xiang, Wenhua; Yan, Wende; Wu, Anchi; Fang, Xi; Deng, Xiangwen] Cent South Univ Forestry & Technol, Fac Life Sci & Technol, Changsha, Hunan, Peoples R China.;[Ouyang, Shuai; Xiang, Wenhua; Yan, Wende; Wu, Anchi; Fang, Xi; Deng, Xiangwen] Natl Engn Lab Appl Technol Forestry & Ecol South, Changsha, Hunan, Peoples R China.;[Ouyang, Shuai; Xiang, Wenhua; Yan, Wende; Wu, Anchi; Fang, Xi; Deng, Xiangwen] Huitong Natl Stn Sci Observat & Res Chinese Fir P, Huitong, Peoples R China.;[He, Honglin] Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing, Peoples R China.;[Ren, Xiaoli; He, Honglin] Chinese Acad Sci, Grad Univ, Beijing, Peoples R China.
通讯机构：
[Deng, Xiangwen] C;Cent South Univ Forestry & Technol, Fac Life Sci & Technol, Changsha, Hunan, Peoples R China.
关键词：
community structure;neutral theory model;niche model;secondary forests;spatial scaling;species abundance distributions
摘要：
To quantify and assess the processes underlying community assembly and driving tree species abundance distributions(SADs) with spatial scale variation in two typical subtropical secondary forests in Dashanchong state-owned forest farm, two 1-ha permanent study plots (100-m x 100-m) were established. We selected four diversity indices including species richness, Shannon-Wiener, Simpson and Pielou, and relative importance values to quantify community assembly and biodiversity. Empirical cumulative distribution and species accumulation curves were utilized to describe the SADs of two forests communities trees. Three types of models, including statistic model (lognormal and logseries model), niche model (broken-stick, niche preemption, and Zipf-Mandelbrodt model), and neutral theory model, were estimated by the fitted SADs. Simulation effects were tested by Akaike's information criterion (AIC) and Kolmogorov-Smirnov test. Results found that the Fagaceae and Anacardiaceae families were their respective dominance family in the evergreen broad-leaved and deciduous mixed communities. According to original data and random sampling predictions, the SADs were hump-shaped for intermediate abundance classes, peaking between 8 and 32 in the evergreen broad-leaved community, but this maximum increased with size of total sampled area size in the deciduous mixed community. All niche models could only explain SADs patterns at smaller spatial scales. However, both the neutral theory and purely statistical models were suitable for explaining the SADs for secondary forest communities when the sampling plot exceeded 40 m. The results showed the SADs indicated a clear directional trend toward convergence and similar predominating ecological processes in two typical subtropical secondary forests. The neutral process gradually replaced the niche process in importance and become the main mechanism for determining SADs of forest trees as the sampling scale expanded. Thus, we can preliminarily conclude that neutral processes had a major effect on biodiversity patterns in these two subtropical secondary forests but exclude possible contributions of other processes.
摘要：
Xanthium strumarium L is a candidate species for manganese (Mn)-phyto-remediation. To reveal the mechanism of this species adaptive to Mn stress, the growth, Mn subcellular distribution, chemical forms, as well as micro-structure and ultra-structure responses of the mining ecotype (ME) of X. strumarium to Mn stress were studied with the non-mining ecotype (NME) as the reference by a hydroponic experiment. The results showed the ME demonstrated a higher tolerance to Mn stress with a superior growth and a higher tolerance index (TI) when compared with the NME. The concentrations of Mn in leaves, stems, and roots of the ME were 1.1-1.8,1.2-1.9, and 13-1.9 times higher than those in the corresponding organs of the NME, respectively. The micro-structure and ultra-structure showed abnormal alterations, such as shrunken ducts and sieve canals, round-shaped chloroplasts, increased starch and osmiophilic granules, as well as expanded and non-compact granum thylakoids in the NME, compared to the ME. More than 83% of Mn was localized in cell wall and soluble fraction, while the Mn concentration in all fractions had a direct linear relationship with Mn treatment in the ME. The proportions of pectates and protein integrated-Mn, phosphate-Mn, and oxalate-Mn forms were dominant in leaves and stems of the ME, whereas, in the NME the relative proportions of inorganic Mn and water-soluble Mn forms in the roots was higher than the other forms. Altogether, the combination of preferential distribution of Mn in the cell wall and soluble fraction, and storage of Mn in low toxicity forms, such as phosphate-Mn, pectates and protein-bound Mn, and oxalate-Mn, might be responsible for alleviating Mn toxicity in the ME. (C) 2019 Published by Elsevier Ltd.
