Native tree species play a crucial role in addressing the challenge of seasonal drought in South China. In this study, one-year-old seedlings of eight native tree species in Guangdong Province were subjected to continuous simulated drought stress and rewatering. In order to identify key drought-resistant traits and best performing tree species, physiological and biochemical responses were assessed through 21 indicators. The results showed the following: (1) All species exhibited responses to drought stress prior to the fourth day, as evidenced by reductions in morphological indicators (crown breadth and ground diameter) and photosynthetic parameters (chlorophyll content, transpiration rate, net photosynthetic rate and stomatal conductance), along with increases in osmotic substances (soluble protein and proline) and antioxidant-related indicators malondialdehyde, peroxidase and superoxide dismutase). (2) The crown breadth, leaf relative water content, chlorophyll content, and ascorbate peroxidase activity were significantly decreased under drought stress. And these indicators were not recovered to pre-stress levels following rewatering. (3) Mantel tests revealed that growth morphological characteristics, particularly plant height, were significantly and positively correlated with most osmotic substances indicators (p < 0.001). Specifically, plant height showed the strongest coupling with these traits, with Mantel’s r ranging from 0.44 to 0.89. In addition, the leaf relative water content, net photosynthetic rate, superoxide dismutase, and malondialdehyde were regarded as the key drought-resistant traits, providing insights into future research on plant improvement, stress-resilience breeding and even drought resistance mechanisms. (4) The eight tree species are ranked from most to least drought-resistant as follows: Zenia insignis, Michelia macclurei, Phoebe zhennan, Phoebe bournei, Erythrophleum fordii, Dalbergia odorifera, Cinnamomum burmanni and Michelia chapensis. This study provides a scientific basis for selecting tree species for afforestation in seasonally arid regions.

IntroductionArbuscular mycorrhizal fungi (AMF) affect plant performance and ecosystem functioning. The Plant AT-rich protein and zinc-binding protein (PLATZ) transcription factor family plays a pivotal role in the plant growth and meristem activity. However, the potential role of PLATZ genes in regulating arbuscular mycorrhizal (AM) symbiosis remains experimentally uncharacterized.MethodsThis study aimed to identify the PLATZ genes in Eucalyptus grandis and to preliminarily characterize their dual involvement in both growth regulation and AM symbiosis. A genome-wide identification and expression analysis of EgPLATZ genes was conducted through bioinformatics approaches and transcriptomic data.ResultsTwenty EgPLATZ members were identified and classified into 4 distinct clades, which is consistent with conserved domain architectures observed in other plant species. EgPLATZs are enriched in cis-regulatory motifs associated with cell expansion, phytohormone signaling, meristem activity, and mycorrhizal symbiosis, especially NODCON2GM (100%), PIBS (50%) and AW-box (75%). The protein predictions suggest that EgPLATZ proteins interact with Dof proteins and transcription initiation factors, indicating a conserved transcriptional mechanism analogous to that observed in other species. EgPLATZs exhibit tissue-specific expression patterns, and EgPLATZ14 and EgPLATZ15 were highly expressed in roots and leaves, respectively. Six EgPLATZs were generally down-regulated under AM symbiosis, with EgPLATZ15 and EgPLATZ2 showing significant downregulation.DiscussionThese results suggest that certain EgPLATZs may function at the interface of developmental signaling and mycorrhizal colonization. This study provides the genome-wide characterization of PLATZs in E. grandis, establishing a functional framework for future investigations into their roles in growth and symbiosis, and suggestion potential candidate genes involved in AMF-responsive in E. grandis.

IntroductionWRKY transcription factors are essential for plant growth, health, and responses to biotic and abiotic stress.MethodsIn this study, we performed a deep in silico characterization of the WRKY gene family in the genome of Eucalyptus grandis. We also analyzed the expression profiles of these genes upon colonization by the arbuscular mycorrhizal fungus (AMF) Rhizophagus irregularis (Ri) and infection with the bacterial pathogen Ralstonia solanacearum (Rs).ResultsA total of 117 EgWRKYs were identified. Phylogenetic analysis divided the EgWRKY proteins into three groups: group I (21 proteins, 17.95%), group II (65 proteins, 55.56%), and group III (24 proteins, 20.51%). Additionally, seven EgWRKY proteins (5.98%) were categorized into group IV due to the absence of the WRKY domain or zinc-finger structure. All EgWRKY genes are distributed irregularly across the 11 chromosomes, with 25 pairs identified as segmental duplicates and four as tandem duplicates. The promoter regions of 50% of members of each subfamily contain plant hormone-related cis-elements associated with defense responses, such as ABREs, TGACG motifs, and CGTCA motifs. All subfamilies (except for group IV-b and IV-c) contain AW-boxes, which are related to mycorrhizal induction. Furthermore, transcriptomic analysis revealed that 21 EgWRKYs were responsive to the AMF Ri, with 13 and 8 genes strongly up- and downregulated, respectively. Several genes (including EgWRKY116, EgWRKY62, and EgWRKY107) were significantly induced by Ri; these genes might enhance the defense of E. grandis against Rs.DiscussionTherefore, we identified E. grandis WRKY genes that are regulated by AMF colonization, some of which might improve the defense of E. grandis against R. solanacearum. These findings provide insights into E. grandis WRKY genes involved in interactions among the host plant, AMFs, and R. solanacearum.

Introduction:Eucalyptus is one of the most productive trees, with short-rotation and high values. Fertilization and inoculating arbuscular mycorrhizal (AM) fungi can increase Eucalyptus productivity. Many studies have concentrated on plant absorption of inorganic nitrogen, but less on organic nitrogen and the effect of AM fungi on organic nitrogen acquisition. Methods:In this study, we set 28 treatments including with or without Rhizophagus irregularis inoculation, three organic nitrogen sources (glycine, L-glutamine and peptone) and four levels of nitrogen and phosphorus fertilization, with no application of organic nitrogen fertilizer as control. Results and Discussion:The results indicated that the height, ground diameter and crown width of Eucalyptus seedlings under 2.5 mM glycine and 0.3 mM Pi (G2P2) treatment were 3.23, 0.82 and 3.70 times higher than those without organic nitrogen under 0.03 mM Pi (N0P1) treatment, respectively. Inoculation with AM fungi contributed 10.85%-162.00% increase in dry weight compared to non-mycorrhizal (NM) treatments. Mycorrhizal seedlings also showed significantly higher total phosphorus contents, nitrogen use efficiency and activity of glutamine synthetase, relative to NM treatments. The relative expressions of genes related to organic nitrogen transport (EgAAP3, EgLHT1, EgProt2) and nitrate nitrogen transport (EgNPF4.5, EgNPF6.3, EgNPF8.1) were up-regulated in mycorrhizal Eucalyptus roots, compared to the NM treatment. Non-mycorrhizal Eucalyptus favored peptone, while mycorrhizal Eucalyptus preferred glycine. Eucalyptus growth under 2.5 mM organic nitrogen and 0.3 mM Pi (N2P2) treatments were promoted markedly, regardless of organic nitrogen source. Whereas, the growth of mycorrhizal Eucalyptus under 0.25 mM organic nitrogen and 0.3 mM Pi (N1P2) treatments were increased the most. This study explored the organic nitrogen and AM fungi fertilizer mode for Eucalyptus, this has potential to improve production practice of Eucalyptus under low nitrogen and phosphorus condition.

Microbiota living in the rhizosphere influences plant growth and fitness, from the opposite perspective; whether host genotypes control its root microbiota is of great interest to forest breeders and microbiologists. To improve low-yield plantations and promote sustainable management of Camellia oleifera, high-throughput sequencing was used to study the chemical properties and microbiome in rhizosphere soil of Camellia forests under three genotypes (common C. oleifera, local C. gauchowensis, and C. chekiangoleosa) and three growth stages (sapling stage at 4-year-old, primary fruit stage at 7-year-old, and full fruiting stage at 11-year-old). The results showed that the rhizosphere soil organic matter (OM), nutrient concentrations, diversity, and community composition of the microbiome were significantly varied among different Camellia genotypes. The relative abundance of symbiotic and pathotrophic fungi in the rhizosphere soil of C. chekiangoleosa was significantly higher than that of C. gauchowensis. Concentrations of OM, available phosphorus (AP), and bacterial alpha diversity increased with tree age. Fungi of Saitozyma, Mortierella, and Glomeromycota and bacteria of Burkholderia-Caballeronia-Paraburkholderia and Vicinamibacterales had potential for fertilizer development for Camellia plantation. Camellia genotypes and growth stages were significantly correlated with the rhizosphere soil pH, OM, and available potassium (AK). Soil pH and OM were key factors that affected the microbiome in the Camellia rhizosphere soils. In conclusion, tree genotypes and growth stages shaped microbial communities in Camellia rhizosphere soils, and some plant growth-promoting rhizobacteria were identified as preliminary candidates for improving Camellia plantation growth.

In southern China, seasonal droughts and low soil phosphorus content constrain the productivity of Eucalyptus trees. To understand the rhizosphere microbiome response to the dry season, metagenomic sequencing analysis was used to investigate the 6-year-old Eucalyptus rhizosphere microbiome under four different irrigation and fertilization treatments. The results showed that irrigation and fertilization during the dry season significantly altered the composition of microbiome in the rhizosphere soil of Eucalyptus plantations. The soil physicochemical properties and enzyme activity explained 30.73 % and 29.75 % of the changes in bacterial and fungal community structure in Eucalyptus rhizosphere soil, respectively. Irrigation and fertilization during the dry season significantly altered the physicochemical properties of rhizosphere soil. Compared with the seasonal drought without fertilizer treatment (CK), the dry season irrigation with fertilizer treatment (WF) significantly increased the content of total nitrogen (46.34 %), available nitrogen (37.72 %), available phosphorus (440.9 %), and organic matter (35.34 %). Soil organic matter (OM), pH, and available phosphorus (AP) were key environmental factors influencing the microbial community composition. Moreover, irrigation and fertilization promoted carbon fixation and nitrogen and phosphorus mineralization, increasing soil OM content and the availability of inorganic nitrogen and phosphorus. Meanwhile, compared to the CK, the increase of acid phosphatase (16.81 %), invertase (146.89 %)and urease (59.45 %) in rhizosphere soil under irrigation (W) treatment further proves that dry season irrigation promote the soil carbon, nitrogen and phosphorus cycles. Irrigation and fertilization treatment alleviated the constraints of low phosphorus in southern China's soil, which promoted Eucalyptus productivity. In conclusion, we suggest implementing reasonable irrigation and fertilization strategies in the production practice of Eucalyptus and utilizing microbial resources to improve soil fertility and Eucalyptus productivity.

Irrigation and fertilization are essential management practices for increasing forest productivity. They also impact the soil ecosystem and the microbial population. In order to examine the soil bacterial community composition and structure in response to irrigation and fertilization in a Eucalyptus plantations, a total of 20 soil samples collected from Eucalyptus plantations were analyzed using high-throughput sequencing. Experimental treatments consisting of control (CK, no irrigation or fertilization), fertilization only (F), irrigation only (W), and irrigation and fertilization (WF). The results showed a positive correlation between soil enzyme activities (urease, cellulase, and chitinase) and fertilization treatments. These enzyme activities were also significantly correlated with the diversity of soil bacterial communities in Eucalyptus plantations.. Bacteria diversity was considerably increased under irrigation and fertilization (W, F, and WF) treatments when compared with the CK treatment. Additionally, the soil bacterial richness was increased in the Eucalyptus plantations soil under irrigation (W and WF) treatments. The Acidobacteria (38.92–47.9%), Proteobacteria (20.50–28.30%), and Chloroflexi (13.88–15.55%) were the predominant phyla found in the Eucalyptus plantations soil. Specifically, compared to the CK treatment, the relative abundance of Proteobacteria was considerably higher under the W, F, and WF treatments, while the relative abundance of Acidobacteria was considerably lower. The contents of total phosphorus, accessible potassium, and organic carbon in the soil were all positively associated with fertilization and irrigation treatments. Under the WF treatment, the abundance of bacteria associated with nitrogen and carbon metabolisms, enzyme activity, and soil nutrient contents showed an increase, indicating the positive impact of irrigation and fertilization on Eucalyptus plantations production. Collectively, these findings provide the scientific and managerial bases for improving the productivity of Eucalyptus plantations.

[背景]桉树(Eucalyptus)青枯病危害严重,丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)与桉树共生影响桉树对青枯病的抗性,而AMF响应桉树青枯菌侵染的机制仍不清楚.[目的]探索AMF响应桉树茄科雷尔氏菌(Ralstonia solanacearum)的侵染机制.[方法]以非菌根化和异形根孢囊霉(Rhizophagus irregularis)菌根化巨桉(Eucalyptus grandis)分别受茄科雷尔氏菌侵染 0、24、48 和 96 h接种后(hour post-inoculated,hpi)的根系组织为研究对象,基于转录组测序筛选和鉴定菌根化巨桉根系中异形根孢囊霉响应茄科雷尔氏菌侵染的基因信息.[结果]与对应非菌根化桉树受茄科雷尔氏菌侵染的时间点相比,菌根化桉树中异形根孢囊霉响应青枯菌侵染显著差异表达基因为 3382-5989 个,随青枯侵染时间进程的增加,异形根孢囊霉特异性响应茄科雷尔氏菌侵染差异表达基因数量逐渐增多.茄科雷尔氏菌侵染 24 hpi时,异形根孢囊霉显著富集共生体生长、孢子形成和凋亡信号通路、铁载体等相关基因;茄科雷尔氏菌侵染 48 hpi时,异形根孢囊霉主要提高自身跨膜运输的能力,促进自身钾、氮等养分吸收与交换等;茄科雷尔氏菌侵染 96 hpi时,异形根孢囊霉主要调控氧化还原反应和黄酮类等抗菌物质合成.[结论]菌根化桉树中AMF主要调控其生长加强生态位和营养(如氮、钾、铁)竞争、分泌抗菌物质、激活防御反应以响应青枯菌的侵染,所鉴定的相关基因信息为研究AMF-桉树-青枯菌互作机制提供一定的资源和参考.

[目的]研究桉树响应从枝菌根真菌和青枯菌的生长和生理特征,为应用菌根化育苗技术防控桉树青枯病提供理论支撑.[方法]以巨桉幼苗为对象,研究摩西管柄囊霉菌根化和青枯菌侵染进程对寄主生长和防御相关酶活性的影响.[结果]1)摩西管柄囊霉能与巨桉根系良好共生,菌根化桉树株高、地径、干质量、根冠比分别为非菌根化处理的2.30、4.38、2.75和1.71倍.与非菌根化处理相比,菌根化巨桉幼苗根长、根直径、根表面积、根体积、根冠比、根系和叶片中氮、磷和钾含量均显著增加(P＜0.05).2)随青枯菌侵染时间的增加,菌根化桉树叶片中的防御相关酶活性显著高于对应的非菌根化处理,过氧化物酶(POD)和多酚氧化酶(PPO)、β-1,3-葡聚糖酶活性在菌根化桉树组织中先升高后降低,分别在青枯菌侵染48、24、144hpi时达到峰值;菌根化桉树叶片中的超氧化物歧化酶(SOD)、苯丙氨酸解氨酶(PAL)和几丁质酶活性先升高后降低,在青枯菌侵染96 hpi后达到峰值.3)接种摩西管柄囊霉对桉树青枯病的防控效果为81.67％.[结论]接种摩西管柄囊霉显著促进桉树幼苗健壮生长,受青枯菌侵染后,菌根化桉树幼苗快速和大幅度提高防御相关酶活性,增强寄主防御青枯菌的能力.

Plantation forests productivity is severely limited by the seasonal drought and fertilization practices in South China. Soil nutrient and water availability influence soil fungal community, functional group diversity and the variation of plant productivity; however, the effects of irrigation and fertilization on fungal responses have rarely been studied. Here, we investigate the responses of fungal community structure and functional groups in Eucalyptus plantation soils to short-term fertilization (F), dry-season irrigation (W), short-term fertilization combined with dry-season irrigation (FW), and control (CK) treatments for ten months. A higher proportion of Basidiomycota was observed in the irrigation and/or fertilization treatments; conversely, lower proportions of Ascomycota and Mucoromycotina were observed in the only irrigation and fertilization treatments. Higher soil carbon contents and symbiotroph fungi (mainly Ectomycorrhizas) proportion were detected in the FW treatment, while low proportions of saprophytic and pathogenic fungi were observed in the FW treatment when compared with those in other treatments. These results may indicate that Eucalyptus tree growth under irrigation and fertilization condition was better than under fertilization only, irrigation only, or neither management. The results highlight that short-term fertilization and dry-season irrigation can shift fungal community structure and functional groups by regulating available soil moisture and nutrients. They also provide a theoretical basis for the development of more appropriate management approaches in the early stages of forest plantation.

结合国内涉农高等院校的林学专业特点,主要针对本科生"文献检索与科技论文写作"课堂教学与实践教学过程中存在的学生对该课程认知和重视程度不高、现用教材与专业的契合度不足、学生上机实践能力不足、信息素质教育不足以及学术行为失范等问题,在分析学科培养目标和学生情况的基础上,提出农林院校该类课程的教学改革新思路.从教学模式、课程内容等方面,对该门类课程进行教学改革的初步探索,旨在有效地提升该类课程的教学质量与教学效果.

为明确广东省油茶品种(系)对炭疽病的抗性及引起油茶炭疽病的病原菌种类,对广东省肇庆市、广州市和韶关市的149个油茶品种(系)进行田间抗性调查,从发病组织中分离纯化致病菌,观察菌株形态学特征,并结合3-磷酸甘油醛脱氢酶(glyceraldehyde-3-phosphate dehydrogenase,GAPDH)基因扩增序列进行分子生物学鉴定.结果显示,有93.29％的油茶品种(系)发生炭疽病,3个调查地油茶炭疽病的平均发病率为18.86％～24.25％,较抗病的油茶品种(系)占调查总数的53.02％,感病油茶品种(系)占调查总数的46.98％.其中,海南3号、长林400号和湘林89号等10个品种(系)表现为近免疫,揭阳5号、桂14号和湘林350号等16个品种(系)表现为高抗,赣5190号、湘林27号和岑软11号等53个品种(系)表现为中抗,赣兴46号、赣州S4号和赣州R10号等36个品种(系)表现为中感,岑软11-3000号、长林53号和湘林67号等34个品种(系)表现为高感,其中岑软11-19号发病率高达65.00％.共分离获得油茶炭疽病致病菌25株,结合形态学特征和基于GAPDH序列的系统发育树分析,将其中24株鉴定为果生炭疽菌Colletotrichum fructicola,1株鉴定为为暹罗炭疽菌C.siamense.筛选的油茶抗病品种(系)可作为广东省油茶良种选育材料,且该省油茶炭疽病主要由果生炭疽菌引起.

Background Herbal tea residue (HTR) is generally considered to be the waste of herbal tea beverage production while it still retains rich nutrients and active substances. The main aim of the present study was to investigate the effect of fermentation technology on improving the quality of HTRs, and focus on the fermented HTR-induced alleviation of summer heat stress in fattening cattle. Results In this study, the waste HTR was fermented and then fed to a total of 45 fattening cattle that were divided into 3 groups (fermented HTR replaced 0, 15, 30% of the forage component of the diet), and the feeding experiment was lasted for 40 days. The physiological indexes, growth performance and fecal microbiota of fattening cattle were evaluated and results showed that fermented HTR could effectively reduce the respiratory rate and rectal temperature of fattening cattle under heat stress, increase the daily feed intake and daily gain, and improve the antioxidant content and blood immune index. In addition, we studied the fecal microbiota composition of 6 fattening cattle in control and 30% HTR substitution groups and found fermented HTR significantly changed the composition of fecal microbiota and increased microbial diversity, and correlation analysis suggested that the bacteria were closely related to fecal SCFA levels of fattening cattle under heat stress. Conclusions In this study, fermented HTR replaced 30% of the forage component of the diet that can change the intestine microorganisms, maintain health and alleviate the heat stress of fattening cattle.

BACKGROUND:Buffalo milk is rich in various nutritional components and bioactive substances that provide more essential health benefits to human body. Recently, exosome identified in the breast milk has been reported as a neotype nutrient and can mediate intercellular communication with exosomal miRNAs. In the present study, we therefore hypothesized that exosome-derived miRNAs from buffalo milk would play the potential physiological importance of consumption of buffalo milk.RESULTS:We isolated exosomes from buffalo and cow milk samples that were obtained at mid-lactation period, and the exosomal miRNA profiles were then generated using miRNA-seq. In addition, miRNAomes of pig, human and panda milk exosomes were downloaded from GEO database. Finally, a total of 27 milk exosomal miRNA profiles that included 4 buffalo, 4 cow, 8 pig, 4 human and 7 panda were analyzed using the miRDeep2 program. A total of 558 unique miRNA candidates existed across all species, and the top 10 highly expressed miRNA were evolutionarily conserved across multiple species. Functional analysis revealed that these milk enriched miRNAs targeted 400 putative sites to modulate disease resistance, immune responsiveness and basic metabolism events. In addition, a total of 32 miRNAs in buffalo milk were significantly up-regulated compared with non-buffalo milks, while 16 were significantly down-regulated. Of interest, functional analysis showed that up-regulated miRNAs were mainly related to host metabolism processes, while the predicted functions of down-regulated miRNAs were enriched in immune response.CONCLUSION:In this study, we explored the exosomal miRNAome differences between milks of different animals, expanding the theoretical basis for potential applications of the miRNA-containing vesicles.

Herbal tea residue (HTR) is a reusable resource with high nutritional value and bioactive substances content, which can be used as a feed additive. In the present study, HTRs were fermented by lactic acid bacteria, and then fed to a total of 90 Holstein heifers, termed as CN, LC, and HC groups. The supplementation improved physiological indices of respiratory frequency and rectal temperature, increased the concentrations of immunoglobulins and antioxidant capacity-related parameters, and reduced the concentrations of heat stress-related parameters and serum hormones. The heifers' body height increased considerably, while their energy metabolism rates were stimulated in response to fermented HTRs. We also studied the fecal microbial community composition of 8 Holstein heifers in each group, and employed correlation analysis with tested parameters. We found that the bacteria were closely related to characteristics including the energy utilization rate, growth performance, serum biochemical indexes, and fecal SCFA levels of the heifers. Based on our findings, the 5% fermented HTRs replaced corn silage might be advantageous for the heifers' characteristics under heat stress.

Summer temperatures are generally high in Southern China, and cows are likely to suffer a heat stress reaction. Heat stress will have a negative impact on the performance of dairy cows; however, the mechanism by which high temperature affects lactation is not clear. CircRNA is a type of non-coding RNA discovered in recent years, which performs a crucial function in many biological activities. However, the effects of circRNA on lactation function of dairy cows under heat stress is unknown. The present study aimed to explore the expression levels of circRNA in the mammary gland tissue of cows under heat stress. Firstly, we collected blood and milk samples of summer and winter cows and evaluated lactation performance using serum indicators, milk production, and milk composition. Incorporating the calculation of the temperature and humidity index, we conformed the heat stress status of cows in summer. Heat stress increased the concentration of HSP70 and decreased the concentration of SOD and PRL. Heat stress not only reduced milk yield but also affected milk quality, with milk lactose and milk protein decreasing with increased temperature. The analysis of the fatty acid composition in summer milk found significantly reduced concentrations of unsaturated fatty acids, especially long-chain unsaturated fatty acids. Sequencing of the cow's mammary gland transcriptome revealed that compared to the appropriate temperature (ST) group, the heat stress (HS) group had a total of 2204 upregulated and 3501 downregulated transcripts. GO enrichment and KEGG pathway analysis showed that these genes were mainly related to milk fat metabolism. In addition, 19 upregulated and 19 downregulated circRNA candidates were found in response to heat stress. We used Pearson's test to establish the correlation of circRNA-mRNA and identified four pairs of circRNA-miRNA networks between four circRNAs, six miRNAs, and the CD36 gene. In this study, we revealed the possible role of circRNAs in lactation of dairy cows and identified that circRNA-miRNA-mRNA networks might exist in the cow's mammary glands, providing valuable experience for dairy lactation and milk quality.

采用叶盘法对供试寄主杨树进行落叶松-杨栅锈菌夏孢子人工接种处理,研究了杨树对落叶松-杨栅锈菌抗病性的生理机制.结果 表明,接种病原菌后1～8 d,6种杨树的PAL、PPO、几丁质酶和β-N-乙酰氨基葡萄糖苷酶活性均升高,且酶活性的变化与树种的抗性表现了较好的正相关.抗病较强的美黑01和中绥12号接种病原菌后,PAL、PPO、几丁质酶和β-N-乙酰氨基葡萄糖苷酶活性不仅升高幅度大,而且这些酶活性绝对值也明显高于抗病性较弱(或感病)树种中林美荷、69杨等.同时抗病较强的树种中这些酶高活维持的时间也较长.这些变化促进了抗病物质的形成和积累,从而表现出抗病性.从几种酶活性测定的总体结果来看,PAL和几丁质酶在受侵各杨树种(品种)体内的活性增幅较其他酶类明显较高,故这几种酶可作为杨树抗叶锈病的生理指标.

Heat stress negatively influences milk production and disrupts normal physiological activity of lactating sows, but the precious mechanisms by which hyperthermia adversely affects milk synthesis in sows still remain for further study. Circular RNAs are a novel class of non-coding RNAs with regulatory functions in various physiological and pathological processes. The expression profiles and functions of circRNAs of sows in lactogenesis remain largely unknown. In the present study, long-term heat stress (HS) resulted in a greater concentration of serum HSP70, LDH, and IgG, as well as decreased levels of COR, SOD, and PRL. HS reduced the total solids, fat, and lactose of sow milk, and HS significantly depressed CSNαs1, CSNαs2, and CSNκ biosynthesis. Transcriptome sequencing of lactating porcine mammary glands identified 42 upregulated and 25 downregulated transcripts in HS vs. control. Functional annotation of these differentially-expressed transcripts revealed four heat-induced genes involved in lactation. Moreover, 29 upregulated and 21 downregulated circRNA candidates were found in response to HS. Forty-two positively correlated circRNA-mRNA expression patterns were constructed between the four lactogenic genes and differentially expressed circRNAs. Five circRNA-miRNA-mRNA post-transcriptional networks were identified involving genes in the HS response of lactating sows. In this study we establish a valuable resource for circRNA biology in sow lactation. Analysis of a circRNA-miRNA-mRNA network further uncovered a novel layer of post-transcriptional regulation that could be used to improve sow milk production.

为探索桉树人工林土壤真菌群落对短期施肥的响应特征,本研究利用Illumina高通量测序技术和FUNGuild平台,分析短期施肥和不施肥(control,CK)处理下土壤真菌的群落结构、功能类群及其影响因子.结果 表明:桉树土壤真菌群落主要由担子菌门和子囊菌门主导,分别占48.61％-46.74％和39.31％-38.08％,短期施肥对真菌门水平的影响不显著.在目水平上,施肥处理中牛肝菌目(23.73％)和散囊菌目(19.95％)的相对丰度显著高于CK处理,分别为CK的7.65和1.72倍,而古根菌目、爪甲团囊菌目、银耳菌目等优势菌目的相对丰度则低于CK处理.短期施肥后土壤真菌α多样性和丰富度指数有所降低,主坐标分析表明,施肥组与CK组真菌群落结构差异显著.桉树土壤真菌的营养类型以腐生型为主,施肥处理中共生型真菌相对丰度显著增加,是CK的4.19倍,且增加以外生菌根马勃菌为主,而大多数其他营养类型真菌的相对丰度则显著减少.冗余分析表明,土壤有效养分含量、微生物碳、土壤有机碳、pH值和土壤含水量等土壤因子是影响群落的主要因子.短期施肥显著改变桉树人工林土壤真菌群落结构和功能类群,增加共生真菌比例,改善土壤质量.

Moringa oleifera and Morus alba leaves are nutritious non-traditional feed ingredients containing bioactive substances. This study was to evaluate the potential application of dietary Moringa and Morus leaf powder on the growth traits, carcass characteristics and meat quality of finishing pigs. Moringa did not alter growth performance or carcass characteristics, but it decreased meat b* value, increased MyHCIIa and decreased MyHCIIx mRNA levels, and increased CP and concentrations of Ala, Thr, Ile, Lys and Pro in longissimus thoracis. Morus increased final BW, ADFI and ADG, decreased F/G ratio, improved slaughter weight, carcass weight, carcass yield and meat a* value, and decreased shear force, drip loss, MyHCIIx and MyHCIIb mRNA levels, and increased MyHCI and MyHCIIa mRNA levels. Morus also increased CP, Glu, Gly, Ala, Arg, Ile, Phe, Pro, Ser, Tyr and Asp, and C16:1, C18:1n9c, C20:4n6, C18:3n3, C20:3n3, C22:1n9 and n-3 PUFA, but decreased C12:0 and C16:0. In summary, Morus improved the parameters and held great potential as an unconventional feed crop.