Catalpa bignonioides extract improves exercise performance through regulation of growth and metabolism in skeletal muscles

Objective:To evaluate the effects of Catalpa bignonioides fruit extract on the promotion of muscle growth and muscular capacity in vitro and in vivo.Methods:Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Cell proliferation was assessed using a 5-bromo-2’-deoxyuridine(BrdU)assay kit.Western blot analysis was performed to determine the protein expressions of related factors.The effects of Catalpa bignonioides extract were investigated in mice using the treadmill exhaustion test and whole-limb grip strength assay.Chemical composition analysis was performed using high-performance liquid chromatography(HPLC).Results:Catalpa bignonioides extract increased the proliferation of C2C12 mouse myoblasts by activating the Akt/mTOR signaling pathway.It also induced metabolic changes,increasing the number of mitochondria and glucose metabolism by phosphorylating adenosine monophosphate-activated protein kinase.In an in vivo study,the extract-treated mice showed improved motor abilities,such as muscular endurance and grip strength.Additionally,HPLC analysis showed that vanillic acid may be the main component of the Catalpa bignonioides extract that enhanced muscle strength.Conclusions:Catalpa bignonioides improves exercise performance through regulation of growth and metabolism in skeletal muscles,suggesting its potential as an effective natural agent for improving muscular strength.

Effects of Drought Stress on Osmotic Regulation Substances of Five Catalpa bungei Clones

[Objective] This study aimed to investigate the effects of drought stress on osmotic regulation substances of Catalpa bungei clones. [Method] Potting experimental was carried out with plastic film sealing method, to differentiate the degrees of drought stress based on changes in soil water content and leaf water potential and investigate variations in contents of osmotic regulation substances（free proline,soluble sugar and soluble protein） in leaves of five Catalpa bungei clones under different degrees of drought stresses. [Result] According to changes in soil water content and leaf water potential, the whole process of drought stress was divided into normal level（CK, with soil water content of 97.49% and leaf water potential of-0.54MPa）, light drought（LD with soil water content of 59.96% and leaf water potential of-1.28 MPa）, mediate drought（MD with soil water content of 34.19% and leaf water potential of-2.32 MPa） and severe drought（SD with soil water content of 14.52%and leaf water potential of-2.99 MPa）. The soil water content and leaf water potential of five Catalpa bungei clones reached the highest correlation in exponential fitting, with an average R2of 0.989 3（P0.001）. The free proline content in leaves of five Catalpa bungei clones increased rapidly with the increasing degree of drought stress（P 0.001）. To be specific, free proline contents of Catalpa bungei clones015-1 and 7080 were 34.39 and 33.41 times of the normal level under severe drought conditions, which reached an extremely significant level（P0.001）; the free proline content of Catalpa bungei clone 1-3 rapidly increased to（855.46±227.52） μg/g Fw under light drought conditions. The soluble protein content in leaves showed different variation trends. To be specific, the soluble protein content of Catalpa bungei clone 7080 was the lowest at various drought stages and reached（1.644 ±0.137）mg/g Fw under normal conditions; the soluble protein content of Catalpa bungei clone 1-3 was relatively high under normal conditions and was reduced rapidly under light drought conditions, showing different response patterns. [Conclusion] Osmotic regulation substances in leaves of five Catalpa bungei clones all have certain response to drought stress. Free proline is the most important osmotic regulation substance, followed by soluble protein, while soluble sugar makes no significant contribution. According to changes in content of osmotic regulation substances, Catalpa bungei clone 7080 has relatively high capacity and good drought resistance, while Catalpa bungei clone 1-3 has the rapidest response to drought stress.

Comparative Study on Photosynthetic Characteristics of Different Catalpa bungei Clones

[Objective] This study aimed to provide scientific basis for the early selec-tion and breeding of excellent Catalpa bungei clones. [Method] The Li-6400 portable photosynthesis system was used to analyze the photosynthetic characteristics of five Catalpa bungei clones （1-3, 1-4, 004-1, 015-1 and 7080）. [Result] Al five Catalpa bungei clones had similar change trends of light response curves, but their maxi-mum net photosynthetic rates （Pmax） were in the order of 1-3＆gt;7080＆gt;015-1＆gt;004-1＆gt;1-4, showing that clone 1-3 and clone 7080 had strong light environmental adapt-ability with the light saturation points （LSP） of 1 147.97 μmol/m2＆#183;s and 1 196.31μmol/m2＆#183;s, respectively, while clone 1-4 had the narrowest range of adaptation to light. There were differences in the total photosynthetic amount per area among the five clones that clone 1-4 was the best of 433 974.24 μmol/m2, fol owed by clone 1-3 of 401 290.20 μmol/m2. The transpiration rates （Tr） and stomatal conductances （Cond） of the five clones presented the same change trend. And the diurnal varia-tion curves of net photosynthetic rate （Pn） of clone 1-3, 1-4 and 015-1 showed two typical peaks with obvious midday depression, while clone 004-1 and 7080 didn’t. [Concluson] Considering a variety of photosynthetic characteristics of indica-tors, photosynthetic capacity of clone 1-3 was the best among the five Catalpa bungei clones.

中国楸树(Catalpa bungei C.A.Mey)种质资源遗传多样性的ISSR分析

采用简单序列重复区间标记法(ISSR)分子标记技术,对中国楸树(Catalpa bungeiC.A.Mey)10个类型156个单株进行了遗传多样性分析。从46个简单重复序列引物中筛选出的14个引物共扩增出190条稳定的谱带,其中多态性谱带186条,多态性条带百分率达97.89%。在物种水平上,Nei′s基因多样性指数(H)为0.290 9,Shannon信息指数(I)为0.446 3,基因多样度(Ht)为0.296 7,基因分化系数(Gst)为0.397 1,基因流(Nm)为0.759 2。分析结果表明,楸树各类型间变异占总变异的39.71%,类型内的变异占总变异的60.29%,约为类型间变异的1.5倍,说明中国楸树类型内的变异在其遗传变异中占主导地位。楸树类型间的遗传相似系数介于0.668 4和0.984 9之间,平均为0.863 7。基于遗传相似系数的UPGMA聚类分析,可将楸树10个类型分为4类。

5个楸树(Catalpa bungei)无性系耗水特性比较

水是西北造林育种需要考虑的关键环境因子,速生树种高耗水现象是西北造林中亟待解决的问题。为筛选适宜造林的楸树无性系,本研究利用盆栽称重法及Li-6400XT便携式光合作用分析系统（Li-cor,U.S.）对于5个楸树无性系（004-1、015-1、7080、1-3、1-4）进行比较。结果显示：试验地甘肃天水地区午间14：00时气温达全天最高,为41.1±1.86℃,湿度仅为39.21±2.65%。在此条件下,5个楸树无性系耗水量及耗水速率均出现＂单峰变化＂,可归为＂非蒸腾午休型＂。其中无性系1-3午间耗水速率最大,达到7.9691±0.1367 mmol·m^-2·s^-1;楸树无性系全天耗水量较高,在1630.42±38.27-2089.95±34.14 g·d^-1,平均为1709.30±52.38 g·d^-1,但其日间生产能力较高,日间耗水速率占全天耗水速率92.78%,显著高于毛白杨。与其他4个无性系相比,无性系004-1水分利用效率出现＂双峰＂现象,分别在12：00时及16：00时出现两个峰,全天水分利用效率总和达到15.723±1.231μmol·mmol-1。因此,楸树耗水速率与普通植物相当,耗水量较高的原因与其较大的叶面积有关;无性系004-1较其他4个无性系,具有更高的苗高、地径,且整株叶面积达1.9907±0.032 m^2;在水分利用效率、耗水速率上也表现出良好的水分利用能力和生长能力,可作为当地丰产速生林的优质无性系进行种植。

Overexpression of CfPIP1-1,CfPIP1-2,and CfPIP1-4 genes of Catalpa fargesii in transgenic Arabidopsis thaliana under drought stress

Catalpa fargesii is an important economic tree species used for furniture and timber production because of its high density and hardness.Its survival and growth are severely aff ected and primarily limited by drought stress.Thus,to better understand the mechanism of drought resistance in C.fargesii,we used qRT-PCR to reveal signifi cantly diff erent expression of three plasma membrane intrinsic protein genes:CfPIP1-1,CfPIP1-2 and CfPIP1-4.We then cloned their full-length cDNA sequences and characterized the encoded proteins.We analyzed the genes phylogenetically and predicted conserved motifs,domains,and secondary and tertiary structures.To verify the function ofthe CfPIP1 genes further,we ectopically expressed CfPIP1 transgenes in Arabidopsis thaliana.The results showed that CfPIP1-1,CfPIP1-2 and CfPIP1-4 had several characteristics of aquaporins.The transgenic plants grew better than the WT plants did under drought stress,and overexpression of the CfPIP1 genes increased the plant water content and resistance to drought.Thus,CfPIP1-1,CfPIP1-2 and CfPIP1-4 of C.fargesii play key roles in regulating the intracellular and extracellular water balance and in mediating the plant response to drought.

Allelic variation in the coumarate 3-hydroxylase gene associated with wood properties of Catalpa fargesii Bur.

Coumarate 3-hydroxylase(C3h)genes participate in the synthesis of lignin and may affect the properties of wood that are important for its commercial value.A better understanding of the natural variation in C3h genes and their associations to wood properties is required to effectively improve wood quality.We used a candidate gene-based association mapping approach to identify CfC3h allelic variants associated with traits that affect the wood properties of Catalpa fargesii.We first isolated the full-length CfC3h cDNA(1825 bp),which was expressed at relatively high levels in xylem according to real time-polymerase chain reaction.In totally,17 common single-nucleotide polymorphisms(minor allele frequency>5%)were identified through cloning and sequencing the CfC3h locus from a mapping population(including 88 unrelated natural C.fargesii individuals collected from main distribution area).Nucleotide diversity and linkage disequilibrium(LD)in CfC3h indicate that CfC3h has low nucleotide diversity(π_(t)=0.0031 andθ_(w)=0.0103)and relatively low LD(within 1800 bp;r^(2)≥0.1).An association analysis identified eight common single-nucleotide polymorphisms(SNPs)(false discovery rate,Q<0.10)and ten haplotypes(Q<0.10)associated with wood properties,explaining 4.92-12.09%of the phenotypic variance in an association population consisted of 125 unrelated natural individuals(The 88 individuals from the mapping population were comprised in the association population).Our study would provide new insight into C3h gene affecting wood quality,and the SNP markers identified would have potential applications in marker-assisted breeding in the future.

Global Lysine Acetylome Analysis of Flower Bud Development in Catalpa bungei

Lysine acetylation,a reversible and dynamic post-translational modification,plays pivotal roles in regulating many biological processes in plants.However,the information of lysine acetylation during flower development of woody angiosperm remains unclear.Herein,we identified a total of 667 lysine acetylation sites in 467 proteins in flower buds of Catalpa Bungei.The acetylated proteins were mainly involved in the pathways of carbon metabolism,glycometabolism and oxidative phosphorylation.Using functional enrichment analysis,61 and 13 acetylated proteins were involved in the glycometabolism and oxidative phosphorylation pathways,respectively.This suggests that lysine acetylated proteins play critical roles in the energy metabolism pathways.Accordingly,the protein–protein interactions were also highly enriched in the carbon metabolic pathway.Integrative analysis of lysine acetylome and transcriptome showed that transcript level changes of seven key lysine-acetylated proteins/genes involved in energy metabolism were significant different during floral transition.Importantly,compared with the normal flowering variety,the expression levels of phosphoribulokinase,phosphoenolpyruvate carboxykinase,ATP synthase and pyruvate dehydrogenase complex genes were significantly up-regulated at the stages of vegetative and transition buds during early flowering of C.bungei.These data represent the first lysine acetylome in the C.bungei flowers,and can serve as an essential basis for exploring the function of lysine acetylated proteins in the flower bud development of plants.

我国北方楸树资源(Sect.Sinocatalpa)繁育技术研究进展

目前楸树繁殖的方式主要有种子育苗、嫁接、埋根、扦插、组培、体胚发生技术等几种。种子育苗(除去杂交育种外)、埋根作为一种传统的繁育手段,已经逐渐被其他无性繁育手段代替。在无性繁殖手段方面:嫁接和扦插在现阶段生产上表现出不可替代的优势,是目前种苗繁育的重要策略,但长远看来这2种手段仍然存在一定的问题。指出组培、体胚发生等新技术作为繁育技术的发展方向具有巨大的潜力,但也存在一些技术性难点需要进一步解决,同时,还要着力解决好与生产环节衔接等方面的诸多问题。综合判断,最终楸树繁育的最佳方式还是要走向体胚发生。

Phylogeny of Catalpa （Bignoniaceae） inferred from sequences of chloroplast ndhF and nuclear ribosomal DNA

Phylogenetics of Chilopsis and Catalpa (Bignoniaceae) was elucidated based on sequences of chloro-plast ndhF and the nrDNA ITS region. In Bignoniaceae, Chilopsis and Catalpa are most closely related as sister genera. Our data supported section Macrocatalpa of the West Indies and section Catalpa of eastern Asian and North American continents. Within section Catalpa, Catalpa ovata of eastern Asia form a clade with North American species, C. speciosa and C. bignonioides, while the other eastern Asian species comprise a clade where C. duclouxii is sister to the clade of C. bungei and C. fargesii. The Caribbean species of Catalpa diverged early from the continental species. More studies are needed to test whether the phylogenetic pattern is common in eastern Asian-North American disjunct genera with species in the West Indies.

锑胁迫下不同楸树无性系的光合生理特性

【目的】为了研究锑胁迫对不同锑耐受型楸树无性系光合生理的影响。【方法】以2种不同锑耐受型楸树无性系为研究对象,分别为敏感型无性系(1-1)和耐受型无性系(5-8)。以无污染的红壤为基质开展盆栽胁迫试验,设置3种锑胁迫处理,质量分数(以锑元素计)分别为0、1200、3000 mg/kg,分别在胁迫0、20、40 d测定2个无性系的生长量、叶片叶绿素相对含量、叶绿素荧光参数和光合参数。【结果】1)在相同锑胁迫条件下,敏感型无性系(1-1)较耐受型无性系(5-8)植株的生长受影响较大。2)在锑胁迫处理下,2个无性系叶片叶绿素相对含量均下降,并且随着锑胁迫质量分数的增加和时间的延长,其叶片叶绿素相对含量逐渐降低,但是耐受型无性系下降幅度远小于敏感型无性系。3)2个无性系在锑胁迫下叶绿素荧光参数存在差异。在同一时间内随着锑胁迫质量分数的升高,可变荧光、PSII最大光化学效率和PSII潜在活性均呈下降趋势,耐受型无性系受影响较小。4)锑胁迫下2个无性系净光合速率均下降,胞间CO_(2)浓度呈上升的趋势,表明在锑胁迫下楸树是受非气孔因素导致的。【结论】在高质量分数锑胁迫下耐受型无性系(5-8)相对于敏感型无性系(1-1)具有更高的叶绿素含量,光合系统受损伤的影响较小,能够更好地应对锑胁迫。

温度和湿度对乙二醛聚合物加固饱水梓木文物性能和微观结构的影响

乙二醛聚合物加固饱水梓木文物在自然环境或者博物馆存放时,受环境因素如温度和湿度的影响会导致文物发生劣化。本研究采用傅里叶红外光谱(FTIR)、扫描电镜(SEM)等方法研究了乙二醛聚合物脱水加固饱水梓木试样在不同温度和湿度环境中性能与微观结构变化。结果显示,饱水梓木文物材料经乙二醛聚合物脱水加固后,乙二醛聚合物与梓木细胞壁结合紧密,部分填充于梓木细胞内加固梓木细胞壁。试样在25℃和50%RH环境中试验30 d其结构和性能无明显变化。在60℃和50%RH环境中试验30 d,试样内部的乙二醛聚合物逐渐均匀附着于细胞壁且表面平滑,试样横截面断口平整;但试样表面的乙二醛聚合物逐渐消失,暴露出木材本体。在25℃和95%RH环境中乙二醛聚合物吸湿性明显增强,其与水的结合能力高于梓木细胞壁,乙二醛聚合物与细胞壁之间的结合被破坏,失去加固效果,但仍填充于细胞中。最后分析了温湿度对乙二醛聚合物加固饱水梓木性能与结构的影响机制,并提出了试样在吸湿和脱水过程中乙二醛聚合物与梓木细胞壁的结构变化模型。

锑胁迫对楸树无性系叶片解剖结构的影响

以10个楸树无性系为研究对象,采用室内盆栽的方法,共设置4种浓度的锑胁迫处理,各处理锑元素含量分别为0、600、1200、2000 mg·kg^(-1);以石蜡切片方法观测叶片的解剖结构,探讨锑胁迫对楸树叶片解剖结构的影响。结果表明:除2-8、1-1号2个楸树无性系在2000 mg·kg^(-1)锑胁迫下其叶片中锑含量均下降外,10个楸树无性系在0~2000 mg·kg^(-1)锑胁迫下其叶片中锑含量均随着锑胁迫浓度的增加而增加。在不同浓度的锑胁迫下,5-8、0号2个无性系的叶片厚度均没有显著差异,其余无性系的叶片厚度表现出不同的差异性;随着锑胁迫浓度的增加,不同楸树无性系的叶片厚度表现出不同的变化规律。随着锑胁迫浓度的增加,10个楸树无性系的叶片上表皮厚度和下表皮厚度总体呈现先升高后下降的变化规律。在不同浓度锑胁迫下,10个楸树无性系的叶片组织结构存在一定差异;在600~2000 mg·kg^(-1)锑胁迫下,各楸树无性系平均栅海比排序为5-8号的(0.99)>1号的(0.91)=2-8号的(0.91)>0号的(0.90)>5-2号的(0.89)>8402号的(0.88)=72号的(0.88)>1-1号的(0.86)=20-01号的(0.86)>63号的(0.71)。0~2000 mg·kg^(-1)锑胁迫对楸树无性系叶片结构无明显破坏,楸树对锑具有一定的耐受性。

楸树远缘杂交种花器官性状变异分析

为明确楸树(Catalpa bungei)远缘杂交种花器官性状的表型变异程度和变异规律,以12株楸树远缘杂交种为材料,采用方差分析、相关分析、聚类分析等统计分析方法,对楸树远缘杂交种的花期物候特征、花序性状、花朵性状和花色性状指标进行研究。结果表明:楸树远缘杂交种的花期物候特征差异明显,楸梓杂交种为假三叉分枝,花芽分化能力强,嫁接当年持续多轮开花,花期长达100 d以上,表现出母本性状。楸梓杂交种的花器官特征差异显著,花序轴共7~9轮侧枝,主轴为无限花序,侧枝为二歧聚伞花序,从底层到顶层过度为聚伞花序,处于楸树有限花序到梓树无限花序的过渡性状。花总长度、花筒直径、花筒长度、花冠宽度、花梗长度、雌蕊长度、花药长度、雄蕊长度、不育雄蕊长度的变幅分别为35.42~50.36,10.84~16.13,16.57~24.68,31.58~44.87,9.07~31.99,19.44~27.52,4.85~5.89,13.93~21.10,3.66~6.79 mm,变异系数为10.88%~31.02%,多样性指数(H’)为1.36~1.93,并以9个性状指标将12株杂交种聚为大花型、中花型、小花型3类。楸树杂交种间花色差异显著,以L*、a*、b*值将12株杂交种的唇瓣花斑颜色聚为3类,分别是粉紫色型、紫红色型和紫色型。

楸树DELLA基因家族生信分析及CbuGRAS9的功能分析

通过鉴定楸树(Catalpa bungei)DELLA家族基因并分析CbuGRAS9的基因功能,为楸树生殖调控性状的遗传改良提供理论依据。基于楸树基因组数据,鉴定并克隆了5个与拟南芥(Arabidopsis thaliana)同源的CbuDELLAs基因;利用ExPASy、SWISS-MODEL、Plant-mPloc、PlantCare等在线工具对CbuDELLAs蛋白进行等电点、蛋白结构、亚细胞定位及启动子顺式作用元件预测;以9-1(Catalpa bungei‘Luoqiu No.1’)和‘百日花’楸树(Catalpa‘Bairihua’)为材料,分析了CbuDELLAs基因的表达量差异,并通过异源转化拟南芥证实了CbuGRAS9的分子功能,利用酵母双杂交文库筛选了与CbuGRAS9互作的蛋白。结果表明:5个CbuDELLAs蛋白的氨基酸数目为455~588,蛋白相对分子质量为5.04~6.43 kDa,等电点为4.81~5.14;CbuDELLAs蛋白均含有DELLA和GRAS保守结构域,全部为亲水性蛋白。亚细胞定位预测结果显示CbuDELLAs蛋白均定位于细胞核中。启动子顺式作用元件分析发现,这5个DELLAs基因启动子区均含有参与赤霉素反应的顺式作用元件。qRT-PCR结果显示‘,百日花’楸中CbuDELLAs基因表达量显著高于对照9-1楸,其中CbuGRAS9为差异最显著的基因,CbuGRAS9转基因株系的开花时间被明显推迟。鉴定到与CbuGRAS9互作的蛋白质主要富集在核糖体、氨基酸合成、次级代谢、光合作用、TCA循环等代谢通路。

梓属5个种幼苗生长及生理性状对N素的响应

【目的】分析施氮对梓属5个种幼苗生长及生理性状的差异,旨在为梓属速生丰产林培育技术研究和生产实践提供理论依据。【方法】以梓属的楸树Catalpa bungei、滇楸Catalpa fargesii、黄金树Catalpa speciosa、梓树Catalpa ovata、紫葳楸Catalpa bignonioides 5个种为试材,通过2种氮素水平(施2 g氮和不施氮)处理,研究不同种幼苗生长及部分生理性状对氮素的响应。【结果】施氮处理下5个种的生物量较不施氮显著提高,但对氮素的响应不同,响应最大的是梓树,净增加量为29.633 g·株^(-1),其次为紫葳楸,其他依次为楸树、黄金树和滇楸。楸树和黄金树在两种N素处理下生物量积累均较高,紫葳楸较小。施氮处理下叶绿素含量、光能转化效率(F_(v)/F_(m))和根系活力均显著提高,而叶片硝酸还原酶活力(NR)却显著降低,不同的种对不同性状的响应不同。叶绿素对氮素的响应差异可能是生物量响应差异的重要原因。基于熵权法对两个处理下5个树种进行综合评价,在施氮情况下,综合评价值由大到小依次是梓树>楸树>紫葳楸>滇楸>黄金树;对照情况下,综合评价值由大到小依次是紫葳楸>楸树>黄金树>梓树>滇楸。【结论】在两种施氮水平下,5个树种的生物量排序为楸树>黄金树>滇楸>梓树>紫葳楸;不同树种对氮素的响应差异明显,综合分析发现5个树种幼苗对氮素的响应从大到小依次是紫葳楸>梓树>黄金树>楸树>滇楸。

山东省临沂市楸树人工林立地类型划分与质量评价

使用典型抽样方法在山东临沂的蒙阴、沂水、兰陵等6个县区,选择造林技术和经营措施基本一致的14个样点布设63块楸树人工林临时标准地,调查标准地内立地因子、林分生长因子以及土壤因子,通过主成分分析、聚类分析法分析立地因子对人工林生长的影响,进而对楸树人工林进行立地类型划分与立地质量评价。结果表明:1)最合适的导向曲线为幂函数曲线,经χ~2检验证明所编制的立地指数表合格。2)在影响楸树人工林生长的立地因子中,重要性排序为:土壤质地>坡向>坡位>坡度>土层厚度>海拔,其中土壤质地、坡向、坡位是影响临沂市楸树人工林生长的主导因子。3)以土壤质地、坡向、坡位3个主导立地因子将山东省临沂市楸树人工林划分为13个立地类型,3个地位级。现有立地条件下,最适宜楸树人工林生长的立地特征为:分布在阳坡或半阴坡的下坡位,土壤质地为中壤土的地区,占总标准地数量的13.64%。整体上,临沂市楸树人工林的立地质量有待提高,建议Ⅰ、Ⅱ地位级种植中大径材楸树,Ⅲ地位级种植小径材楸树。

金丝楸CbuCYP71D15基因克隆及表达分析

【目的】通过对金丝楸CbuCYP71D15基因的分子特征和表达模式进行研究分析,为揭示CbuCYP71D15基因在金丝楸心材颜色形成过程中的作用提供参考依据。【方法】基于金丝楸木材样本的转录组数据,采用常规PCR扩增技术克隆获得CbuCYP71D15基因的编码区序列(CDS)全长,利用ProtParam,Protscale,PSORT Prediction等在线工具对CbuCYP71D15基因进行基础生物信息学分析。根据转录组数据,探究CbuCYP71D15基因在边材中的表达水平。同时,采用实时荧光定量PCR(qRT-PCR)的方法分析该基因在金丝楸不同组织部位中的表达模式。【结果】成功克隆得到长为1497 bp的CbuCYP71D15基因序列,生物信息学分析显示该基因编码498个氨基酸,相对分子量为56.5 kD,理论等电点为9.16,是稳定的亲水蛋白,其二级结构主要由α螺旋(46.18%)和无规则卷曲(34.34%)组成,存在跨膜区段。通过序列比对及系统进化分析发现,CbuCYP71D15基因所编码的氨基酸序列与芝麻的同源序列相似度最高,同源蛋白遗传关系最近,且CYP71Ds在进化过程中是保守的,CbuCYP71D15蛋白具有细胞色素P450超家族特征的保守结构域及血红素结合位点,属于CYP71家族。转录组数据分析显示CbuCYP71D15基因在边材中的表达水平与1,4-萘醌类化合物在边材中的表达趋势一致。qRT-PCR分析表明,CbuCYP71D15基因在金丝楸各组织部位均有表达,在边材中表达水平最高,根中表达水平最低。【结论】CbuCYP71D15基因可能在金丝楸心材呈色物质的合成代谢过程中起到羟化作用,可为进一步解析CbuCYP71D15基因在金丝楸中的生物学功能提供依据。

温度和光周期对楸树抗寒性生理生化指标的影响

为探究低温和短日照与楸树抗寒性诱导的关系,以2年生滇楸和灰楸嫁接苗为试材,进行4个温度与光周期组合处理:常温长日照(16 h/8 h,23℃)、常温短日照(8 h/16 h,23℃)、低温长日照(16 h/8 h,5℃)、低温短日照(8 h/16 h,5℃),研究温度和光周期对楸树抗寒性发育的影响,利用电导法(Electrolyte leakage,EL)和电阻抗图谱法(Electrical impedance spectroscopy,EIS)测定抗寒性的变化,测定质膜三磷酸腺苷酶(ATP酶)和5′-核苷酸酶(5′-AMP酶)、可溶性糖及淀粉含量等生理生化指标。结果表明,低温长日照(16 h/8 h,5℃)、低温短日照(8 h/16 h,5℃)对楸树抗寒性增强诱导最快,其中低温短日照处理对抗寒性的诱导又强于低温长日照处理,表明温度对楸树抗寒性增强起主导作用,光周期起次要作用,且温度和光周期对楸树抗寒性的诱导为非加性关系;常温长日照(16 h/8 h,23℃)处理下,2种楸树抗寒性均得到增强,表明在23℃仍能诱导楸树抗寒性的增强;高频电阻率r测定的抗寒性与电导法测定的抗寒性均显著相关,其中低温短日照处理下的抗寒性与电导法测定的抗寒性极显著相关,相关系数达到0.77,表明高频电阻率r可用于楸树抗寒性的测定;随着2种楸树抗寒性的增强,ATP酶和5′-AMP酶活性也上升,均在处理第30天时显著上升并达到高值,其中5′-AMP酶活性均高于ATP酶活性,且滇楸的2种酶活性均高于灰楸。

灰楸光合指标的无性系变异及其与环境因子的关系

分析灰楸无性系光合特性、叶绿素含量与环境因子的关系及遗传变异,旨在鉴定高光合效率、低蒸腾耗散的灰楸优良无性系,为灰楸光合高效育种和优质高效栽培管理提供理论依据。利用LI-6400便携式光合作用测定仪测定光合和气体交换参数,采用SPAD-502叶绿素仪测定叶绿素含量。结果表明,灰楸无性系间净光合速率、蒸腾速率、气孔导度和水分利用效率等4个主要指标存在极显著差异。净光合速率与蒸腾速率、气孔导度、水分利用效率呈极显著正相关,与胞间CO_(2)浓度呈极显著负相关。净光合速率与空气CO_(2)浓度呈负相关。通过回归方程确定了光照强度对瞬时净光合速率、气孔导度、胞间CO_(2)浓度均有较大正贡献。叶绿素含量与瞬时净光合速率呈正显著相关,说明叶绿素含量的高低直接决定楸树光合能力和生长状况。光合指标与环境因子的相关关系显著,光照强度对灰楸无性系瞬时净光合速率影响最大。灰楸无性系光合指标变异系数和重复力均较高,无性系光合能力选择潜力较大。叶绿素含量可作为灰楸早期选育的一个重要参考技术指标,与树高、胸径等共同作为开展灰楸良种选择的关键指标。