BACKGROUND:The helical tomotherapy (HT) system can expose more normal lung tissue to low radiation doses, resulting in extensive low-dose distribution in both lungs which may induce radiation pneumonitis (RP). PURPOSE:This study aims to optimize dosimetric parameters and identify a clinically feasible treatment plan by analyzing the impact of different block settings and modulation factor (MF) combinations on HT plans for lung cancer to reduce the low-dose exposure volumes in normal lung tissue. METHODS:We retrospectively reviewed 14 lung cancer patients who received radiotherapy. These cases were optimized using different modulation factors (MFs: 3, 4, 5) and block techniques (Unblocked, Directional, Complete). The impact of MF and block combinations on reducing low-dose bath (e.g., V5, V10) in lung tissue was evaluated by analyzing dose distribution maps, dose-volume histograms (DVH), homogeneity index (HI), conformity index (CI), and treatment time for each optimized HT plan combination. RESULTS:Block settings and higher MF exerted minimal influence on the average dose to the target volume. With stricter block constraints and higher MF, HI increased (range: 17.39%-27.54%) and CI decreased (range: 2.76%-17.43%); although both indices showed slight deterioration, they remained within acceptable clinical limits. Treatment time increased substantially (range: 15.77%-131.58%). The block technique significantly reduced V5 in the bilateral lungs and the contralateral (healthy) lung, with less impact on the ipsilateral (affected) lung. The combination of block and high MF effectively reduced V5. CONCLUSIONS:To balance target volume coverage (high dose), dose distribution uniformity, and treatment duration while reducing low-dose irradiation to normal lung tissue, we recommend implementing Directional block with an MF range of 3-4 to optimize the HT plan for patients with unilateral lung cancer.

ObjectiveTo quantify the difference between the (collapsed cone convolution) CCC algorithm and the (Monte Carlo) MC algorithm and remind that the planners should pay attention to some possible uncertainties of the two algorithms when employing the two algorithms.MethodsThirty patients’ cervical cancer VMAT plans were designed with a Pinnacle TPS (Philips) and divided equally into two groups: the simple group (SG, target volume was only the PTV) and the complex group (CG, target volume included the PTV and PGTV). The plans from the Pinnacle TPS were transferred to the Monaco TPS (Elekta).The plans’ parameters all remained unchanged, and the dose was recalculated. Gamma passing rates (GPRs) obtained from dose distribution from Pinnacle TPS compared with that from Monaco TPS with SNC software based on three triaxial planes (transverse, sagittal and coronal). GPRs and DVH were used to quantify the difference between the CCC algorithm in pinnacle TPS and the MC algorithm in Monaco TPS.ResultsAmong the statistical dose indexes in DVHs from the Pinnacle and Monaco TPSs, there were 7(7/15) dose indexes difference with statistically significant differences in the SG, and 10(10/18) dose indexes difference with statistically significant differences in the CG. With 3%/3mm criterion, the most (5/6) GPRs were greater than 95% from the SG and CG. But with 2%/2mm criterion, the most (5/6) GPRs were less than 90% from the two groups. In addition, we found that GPRs were also related to the selected triaxial planes and the complexity of the plan (GPRs varied with the SG and CG).ConclusionsObvious difference between the CCC and MC algorithms from Pinnacle and Monaco TPS. DVH maybe better than 2D gamma analysis on quantifying difference of the CCC and MC algorithms. Some attention should be paid to the uncertainty of the TPS algorithm, especially when the indicator on the DVH is at the critical point of the threshold value, because the algorithm used may overestimate or underestimate the DVH indicator.

目的:分析野生华中樱"YS01"花瓣挥发性物质种类、含量及香气特征.方法:采用顶空固相微萃取(SPME)和气相色谱-质谱(GC-MS)联用技术鉴定"YS01"不同发育时期花瓣挥发性物质,并应用气味"ABC"分类法对挥发性物质的香气进行了量化和特征分析.结果:从"YS01"花瓣中鉴定出66种挥发性物质,其中苯丙素类/苯环型化合物32种,脂肪酸衍生物26种,萜烯类及其衍生物5种,杂环化合物3种,挥发性物质的种类及其总释放量随花朵开放而逐渐增加."YS01"花瓣挥发性物质覆盖26种香型,其中水果香、麻醉性香、香荚兰香、青香、辛香和食品香占主导地位.结论:"YS01"花瓣的香韵丰富,香气较为独特,主要香气物质是苯甲醛、对甲氧基苯甲醛、4-甲氧基苯甲酸甲酯、水杨酸甲酯、芳樟醇、反式-2-己烯醛和己醛.

Secondary cell wall (SCW) thickening in plant inflorescence stems is a complicated cellular process that is essential for stem strength and biomass. Although Arabidopsis NAC transcription factor (TF) 1 (NST1) regulates the SCW thickening in anther walls, the single T-DNA-insertion mutant (nst1) does not show disrupted SCW thickening in anther endothecium, interfascicular fibers or xylem. To better understand the regulatory mechanism of this process, we generated an ethyl methanesulfonate (EMS)-mutagenized Arabidopsis population with the nst1 background. scd5 (SCW-defective mutant 5) was isolated in a forward genetic screen from the EMS mutant library, which displayed not only less lignin deposition in the interfascicular fiber and xylem than the wild type but also a pendent inflorescence stem. The EMS-induced mutation associated with the scd5 phenotype was found in the 5th exon of At2G46030 that encodes a ubiquitin-conjugating enzyme (UBC6), we thereby renamed the allele nst1 ubc6. Overexpressing UBC6 in nst1 ubc6 rescued the defective SCW, whereas disrupting UBC6 in nst1 by the CRISPR/Cas9 system caused a phenotype similar to that observed in nst1 ubc6. UBC6 was localized to the nucleus and plasma membrane, and possessed E2 ubiquitin-conjugating activity in vitro. MYB7 and MYB32 are considered as transcription repressors in the phenylpropanoid pathway and are involved in NAC TF-related transcriptional regulation in SCW thickening. UBC6 can interact with MYB7 and MYB32 and positively mediate the degradation of MYB7 and MYB32 by the 26S proteasome. Overall, these results indicated the contribution of UBC6 to SCW thickening in Arabidopsis inflorescence stems.

RNA helicases (RHs) are required for most aspects of RNA metabolism and play an important role in plant stress tolerance. Heat stress (HS) causes the deleterious effects on plant cells, such as membrane disruption and protein misfolding, which results in the inhibition of plant growth and development. In this study, CaRH57 was identified from pepper (Capsicum annuum) and encodes a DEAD-box RH. CaRH57 was induced by HS, and overexpression of CaRH57 in Atrh57-1 rescued the glucose-sensitive phenotype of Atrh57-1, suggesting the functional replacement of CaRH57 to AtRH57. The nucleolus-localized CaRH57 possessed a RH activity in vitro. CaRH57 knockdown impaired pepper heat tolerance, showing severe necrosis and enhanced ROS accumulation in the region of the shoot tip. Additionally, accumulation of aberrant-spliced CaHSFA1d and CaHSFA9d was enhanced, and the corresponding mature mRNA levels were reduced in the TRV2 (Tobacco rattle virus)-CaRH57-infected plants compared with the control plants under HS. Overall, these results suggested that CaRH57 acted as a RH to confer pepper heat tolerance and was required for the proper pre-mRNA splicing of some HS-related genes.

Objective This meta-analysis explored whether the expression of actin filament-associated protein 1 antisense RNA 1（AFAP1-AS1） is related to the prognosis and clinicopathological features of patients with cancer.Methods PubMed, EMBASE, and Cochrane Library were systematically searched. Hazard ratios（HRs） with 95% confidence intervals（CIs） were used to assess the prognostic value based on overall survival（OS）, disease-free survival（DFS）, and progression-free survival（PFS）. Odds ratios（ORs） with 95% CIs were used to determine the relationships between AFAP1-AS1 and clinicopathological features, such as large tumor size（LTS）, high tumor stage（HTS）, poor histological grade（PHG）, lymph node metastasis（LNM）, and distant metastasis（DM）.Results Thirty-five eligible articles and 3433 cases were analyzed. High AFAP1-AS1 expression, compared to low AFAP1-AS1 expression, correlated with significantly shorter OS（HR = 2.15, 95% CI = 1.97–2.34, P ＜ 0.001）, DFS（HR = 1.37, 95% CI = 1.19–1.57, P ＜ 0.001）, and PFS（HR = 1.97, 95% CI = 1.56–2.50, P ＜ 0.001） in patients with cancer. In various cancers, elevated AFAP1-AS1 expression was significantly associated with LTS（OR = 2.76, 95% CI = 2.16–3.53, P ＜ 0.001）, HTS（OR = 2.23, 95% CI = 1.83–2.71, P ＜ 0.001）, and PHG（OR = 1.39, 95% CI = 1.08–1.79, P = 0.01） but not LNM（OR = 1.59, 95% CI = 0.88–2.85, P = 0.12） or DM（OR = 1.81, 95% CI = 0.90–3.66, P = 0.10）.Conclusion High AFAP1-AS1 expression was associated with prognostic and clinicopathological features, suggesting that AFAP1-AS1 is a prognostic biomarker for human cancers.

【Objective】This work aimed to investigate the community structure and species diversity of wild Prunus discoidea in Mufu Mountain, Pingjiang, Hunan Province, so as to provide a theoretical basis for the protection, rational development and utilization of wild cherry germplasm resources.【Method】By using the method of a typical sample plot survey, 27 sample plots were set up to investigate the community structure of the wild Prunus discoidea community in Mufu Mountain, Pingjiang, Hunan Province. The species diversity of the Prunus discoidea community was evaluated based on the Gleason richness index, Simpson dominance index,Shannon diversity index and Pielou evenness index.【Result】The species composition of the Prunus discoidea community in Mufu Mountain of Pingjiang consisted of 38 families, 59 genera and 69 species of vascular plants. The flora was dominated by pantropical plants, followed by north temperate plants. The life-form spectrum was mainly composed of phanerophytes, accounting for 72.46%,followed by geophytes, accounting for 11.59%. The vertical structure was the shrub layer and the herb layer. The ground diameter structure of the community was an “inverted J type”, which is the growing type. The dominant species in the shrub layer of the Prunus discoidea community were Prunus discoidea, Loropetalum chinense and Camellia oleifera, and the dominant species in the herb layer were Nephrolepis cordifolia, Miscanthus floridulus and Cyrtomium fortunei. In terms of the species diversity of the Prunus discoidea community, the Gleason richness index was 5.97 in the shrub layer and 2.26 in the herb layer. The Simpson dominance index was 0.90 in the shrub layer and 0.40 in the herb layer. The Shannon diversity index was 2.94 in the shrub layer and 1.06 in the herb layer. The Pielou evenness index was 0.77 in the shrub layer and 0.38 in the herb layer, and the overall species diversity of the shrub layer was higher than that of the herb layer.【Conclusion】The Prunus discoidea community in Mufu Mountain, Pingjiang, Hunan Province is in the early stage of secondary forest evolution, and the community structure is relatively simple. The species diversity of the herb layer is relatively weak. The Prunus discoidea community belongs to a growing community, in order to maintain stability and expand the growth space of the community. It is necessary to take conservation measures such as pruning surrounding trees.

Plants are capable of regenerating adventitious roots (ARs), which is important for plant response to stress and survival. Although great advances in understanding AR formation of leaf explants have been made, the regulatory mechanisms of AR formation still need to be investigated. In this study, irr1-1 (impaired root regeneration) was isolated with the inhibition of adventitious rooting from Arabidopsis leaf explants. The β-glucuronidase (GUS) signals of IRR1pro::GUS in detached leaves could be detected at 2-6 days after culture. IRR1 is annotated to encode a Class III peroxidase localized in the cell wall. The total peroxidase (POD) activity of irr1 mutants was significantly lower than that of the wild type. Detached leaves of irr1 mutants showed enhanced reactive oxygen species (ROS) accumulation 4 days after leaves were excised from seedlings. Moreover, thiourea, a ROS scavenger, was able to rescue the adventitious rooting rate in leaf explants of irr1 mutants. Addition of 0.1 μM indole-3-acetic acid (IAA) improved the adventitious rooting from leaf explants of irr1 mutants. Taken together, these results indicated that IRR1 was involved in AR formation of leaf explants, which was associated with ROS homeostasis to some extent.

华中樱是原产于我国的野生樱花,湖南省是其主要分布区域,开展湖南省华中樱遗传多样性研究,可为种质资源保护及开发利用奠定基础.通过对核糖体基因转录间隔区(ITS,internal transcribed spacer)序列进行PCR扩增和测序,应用遗传学软件分析了湖南省10个华中樱群体207份个体的遗传多样性和遗传结构.结果表明,湖南省华中樱的总体核苷酸多样性为0.0056,单倍型多样性为0.763,207份种质资源可分为14个单倍型,其中来自怀化市中方县的群体遗传多样性最高,其次是来自衡阳市南岳区的群体,来自郴州市苏仙区的群体的遗传多样性最低.分子方差分析(AMOVA,analysis of molecular variance)结果表明,60％的遗传变异存在于华中樱群体间,40％存在于群体内,大部分群体之间存在较大的遗传分化,其中来自常德市石门县和来自郴州市苏仙区的群体的遗传分化指数高达0.96571.中性检验结果表明,Tajima's D(1.02121)和Fu and Li's D(1.07527)均为正值,但统计检验不显著(P＞0.10);错配分布分析结果显示,错配分布呈双峰曲线,表明湖南省华中樱群体遵循中性进化模式,且进化过程中可能经历了平衡选择或突然群体收缩.Mantel test检验表明,群体之间的地理距离与遗传距离存在显著的正相关性(r=0.3356,P=0.026＜0.05).湖南省华中樱种质资源遗传多样性水平较高,群体间遗传分化明显且符合距离隔离模型.

Prunus clarofolia (Schneid.) Yu et Li is a very attractive wild flowering cherry endemic to China. In this study, the complete chloroplast genome of P. clarofolia was assembled. The total length of the chloroplast genome was 157,899 bp, containing a pair of inverted repeat regions of 26,393 bp each, separated by a small single-copy region of 19,142 bp, and a large single-copy region of 85,971 bp. The overall GC content of the chloroplast genome was 36.71%. The genome contained 131 genes, including 85 protein-coding genes, 37 tRNA genes, eight rRNA genes, and one pseudogene. Phylogenetic analysis revealed that P. clarofolia and P. pseudocerasus showed the closest relationship.

为给优异樱花种质的保存和利用提供理论依据，对47份樱花种质资源进行了RAD简化基因组测序，挖掘高一致性的群体SNP，应用RAxML、ADMIXTURE、GCTA、PopGenome和Arlequin 3.0等生物信息学软件进行了系统进化树构建、基因分型分析、主成分分析和核苷酸多样性分析。经过基因型完整性过滤和紧密连锁位点筛选后，共获得79 667个高一致性群体SNP。系统进化、遗传结构和主成分聚类分析结果基本一致，47份种质资源分为8个类群，各类群的核苷酸多样性（π）和平均期望杂合度（He）分别为Ⅰ：0.128 19,0.119 94；Ⅱ：0.139 64,0.130 55；Ⅲ：0.215 5,0.164 73；Ⅳ：0.086 82,0.061 22；Ⅴ：0.095 49,0.069 73；Ⅵ：0.191 22,0.106 1；Ⅶ：0.168 5,0.158 78；Ⅷ：0.290 98,0.183 43。类群Ⅳ与Ⅴ之间的遗传分化程度最高（FST=0.461 289），其次是类群Ⅳ与Ⅵ（FST=0.456 958），类群Ⅶ与Ⅷ之间的分化程度最低（FST=0.097 613），各类群之间的遗传分化均处于中等及以上水平。基因分型结果显示，单一遗传组分的个体有29个（61.70%），含有2或3种遗传组分的个体有18个（38.30%），潜在的种间自然杂交个体有4个。樱花种质资源的遗传多样性丰富，8个类群之间存在明显的遗传分化。通过基因型分析，明确了种间自然杂交后代和人工杂交品种的遗传组分，初步探讨了亲本来源。

Background There is a close relationship between radiotherapy and autophagy in tumors, but the prognostic role of radiotherapy-related autophagy genes (RRAGs) in lung adenocarcinoma (LUAD) remains unclear. Methods Data used in the current study were extracted from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Weighted gene co-expression network analysis (WGCNA) was executed to recognize module genes associated with radiotherapy. The differentially expressed genes (DEGs) between different radiotherapy response groups were filtered via edgeR package. The differentially expressed radiotherapy-related autophagy genes (DERRAGs) were obtained by overlapping the module genes, DEGs, and autophagy genes (ATGs). Then, prognostic autophagy genes were selected by Cox analyses, and a risk model and nomogram were subsequently built. Gene Set Enrichment Analysis (GSEA) and single-sample Gene Set Enrichment Analysis (ssGSEA) were performed to investigate potential mechanisms through which prognostic autophagy signatures regulate LUAD. Radiotherapy-resistant cell lines (A549IR and PC9IR) were established after exposure to hypo-fractionated irradiation. Ultimately, mRNA expression was validated by quantitative real-time PCR (qRT-PCR), and relative protein levels were measured in different cell lines by western blot. Results A total of 11 DERRAGs were identified in LUAD. After Cox analyses, SHC1 , NAPSA , and AURKA were filtered as prognostic signatures in LUAD. Then, the risk score model was constructed using the prognostic signatures, which had a good performance in predicting the prognosis, as evidenced by receiver operating characteristics curves. Furthermore, Cox regression analyses demonstrated that risk score was deemed as an independent prognostic factor in LUAD. Moreover, GSEA and ssGSEA results revealed that prognostic RRAGs may regulate LUAD by modulating the immune microenvironment and affecting cell proliferation. The colony formation assay showed that the radiosensitivity of radiation-resistant cell lines was lower than that of primary cells. The western blot assay found that the levels of autophagy were elevated in the radiotherapy-resistant cell lines. Moreover, the expression of DERRAGs ( SHC1 , AURKA ) was higher in the radiotherapy-resistant cells than in primary cells. Conclusion Our study explored the role of RRAGs in the prognosis of LUAD and identified three biomarkers. The findings enhanced the understanding of the relationship between radiotherapy, autophagy, and prognosis in LUAD and provided potential therapeutic targets for LUAD patients.

[目的]分析樱属植物Cerasus种间、品种间的叶形态、解剖结构差异,为樱属植物分类提供参考.[方法]运用LI-COR LI3000C叶面积仪、组织透明法和石蜡切片法,对16个樱属植物的叶形态特征(叶柄长、叶长、叶宽、叶面积)和叶片解剖结构(叶表皮细胞特征、气孔特征、解剖结构特征)等20项典型特征指标进行测定.[结果]尾叶樱桃、华中樱桃、迎春樱桃、高盆樱桃、钟花樱桃、大叶早樱、大岛樱7个物种及'染井吉野'之间的形态特征有显著性差异,其他选育或杂交的亲缘关系相近的品种、品种与原种之间差异不显著;试材中叶片表皮微形态特征参数和叶解剖结构的参数存在显著差异(P<0.05),16份樱属植物的试材叶片解剖结构参数中,7个种之间差异显著,其他亲缘关系相近的品种之间差异不显著.除尾叶樱桃叶片上下两面密被长表皮毛,迎春樱桃、'杭州早樱'、大叶早樱有短表皮毛外,其他樱花叶片均无表皮毛.华中樱桃与钟花樱桃的上表皮细胞呈不规则形,其他樱花上表皮细胞均呈多边;尾叶樱桃的叶片下表皮细胞呈多边形,其他樱花叶片下表皮细胞均呈不规则形;迎春樱桃、大叶早樱和'杭州早樱'的叶片上表皮垂周壁式样呈弓形,其余均为平直;钟花樱桃、大叶早樱、'花笠樱'和'郁金樱'的叶片下表皮垂周壁式样呈波状,其他均为弓形;'松月樱'的单个气孔面积最大,气孔密度最小,迎春樱桃的气孔密度是最大,单个面积最小;其中尾叶樱桃、钟花樱桃、大叶早樱、'修善寺寒樱'和'天之川樱'气孔器保卫细胞两极有"T"形加厚;尾叶樱桃、'阳光樱'和'郁金樱'的栅栏组织为1层,其他为2层,叶肉组织均分化为栅栏组织和海绵组织,主脉均为开放的半圆形结构,厚度存在显著性差异(P<0.05).'花笠樱'的下表皮厚度、叶片厚度和栅栏组织厚度最大,高盆樱桃的栅栏组织厚度与海绵组织厚度之比最大.[结论]华中樱桃等7个物种的叶形态特征和解剖结构有显著差异,亲缘关系相近的品种之间差异不显著,叶形态特征和解剖结构可以作为樱属植物种间鉴定和分类的重要依据.

Faithful DNA replication is one of the most essential processes in almost all living organisms. However, the proteins responsible for organellar DNA replication are still largely unknown in plants. Here, we show that the two mitochondrion-targeted single-stranded DNA-binding (SSB) proteins SSB1 and SSB2 directly interact with each other and act as key factors for mitochondrial DNA (mtDNA) maintenance, as their single or double loss-of-function mutants exhibit severe germination delay and growth retardation. The mtDNA levels in mutants lacking SSB1 and/or SSB2 function were 2- to 4-fold higher than in the WT, revealing a negative role for SSB1/2 in regulating mtDNA replication. Genetic analysis indicated that SSB1 functions upstream of mitochondrial DNA POLYMERASE IA (POLIA) or POLIB in mtDNA replication, as mutation in either gene restored the high mtDNA copy number of the ssb1-1 mutant back to WT levels. In addition, SSB1 and SSB2 also participate in mitochondrial genome maintenance by influencing mtDNA homologous recombination (HR). Additional genetic analysis suggested that SSB1 functions upstream of ORGANELLAR SINGLE-STRANDED DNA BINDING PROTEIN1 (OSB1) during mtDNA replication, while SSB1 may act downstream of OSB1 and MUTS HOMOLOG1 (MSH1) for mtDNA HR. Overall, our results yield new insights into the roles of the plant mitochondrion-targeted SSB proteins and OSB1 in maintaining mtDNA stability via affecting DNA replication and DNA HR. This article is protected by copyright. All rights reserved.

[目的]了解蓝莓酒渣花青素的组成以及蓝莓发酵前后花青素组成的差异,提高蓝莓酒渣花青素的利用效率.[方法]以蓝莓酒渣为原料,以柠檬酸酸化的乙醇为提取溶剂,综合考察乙醇体积分数、提取温度、料液比、提取时长和溶剂pH共5个因素对蓝莓酒渣花青素提取的影响.在单因素试验的基础上,采用响应面法对蓝莓酒渣花青素的提取工艺进行优化.使用高效液相色谱仪分析蓝莓酒渣花青素的组成,并对蓝莓发酵前后花青素组成进行比较.[结果]蓝莓酒渣花青素提取的最佳工艺条件为乙醇体积分数70％、提取温度50℃、料液比1:20,溶剂pH=2、提取时长1 h,该条件下提取液中花青素的质量分数可达6.38 mg/g.蓝莓鲜果中主要含有飞燕草色素、矢车菊色素、锦葵色素和一种未知色素,4种色素的相对含量分别为16.92％、11.08％、55.17％和16.83％,蓝莓酒渣中仅含70.48％飞燕草色素和29.52％的锦葵色素,矢车菊色素和未知色素均未检出.[结论]料液比、溶剂pH、提取温度、乙醇体积分数和提取时长5个因素对蓝莓酒渣花青素的提取效率均有显著影响.蓝莓发酵前后花青素组成有较大的区别,蓝莓发酵过程中矢车菊色素和未知色素显著减少,锦葵色素减少量较大,飞燕草色素减少量较小,蓝莓发酵后仅含飞燕草色素和锦葵色素2种花青素.

Faithful DNA replication is one of the most essential processes in almost all living organisms.However, the proteins responsible for organellar DNA replication are still largely unknown in plants.Here, we show that the two mitochondriontargeted single-stranded DNA-binding(SSB) proteins SSB1 and SSB2 directly interact with each other and act as key factors for mitochondrial DNA(mt DNA) maintenance, as their single or double loss-of-function mutants exhibit severe germination delay and growth retardation. The mt DNA levels in mutants lacking SSB1 and/or SSB2 function were two-to four-fold higher than in the wild-type(WT), revealing a negative role for SSB1/2 in regulating mt DNA replication. Genetic analysis indicated that SSB1 functions upstream of mitochondrial DNA POLYMERASE IA(POLIA) or POLIB in mt DNA replication, as mutation in either gene restored the high mt DNA copy number of the ssb1-1 mutant back to WT levels. In addition,SSB1 and SSB2 also participate in mitochondrial genome maintenance by influencing mt DNA homologous recombination(HR). Additional genetic analysis suggested that SSB1 functions upstream of ORGANELLAR SINGLE-STRANDED DNABINDING PROTEIN1(OSB1) during mt DNA replication, while SSB1 may act downstream of OSB1and MUTS HOMOLOG1 for mt DNA HR. Overall,our results yield new insights into the roles of the plant mitochondrion-targeted SSB proteins and OSB1 in maintaining mt DNA stability via affecting DNA replication and DNA HR.

[目的]研究不同蓝莓品种果实的品质特征、抗氧化物质含量、抗氧化能力以及多酚组成的区别,为蓝莓产品开发和生物活性物质的高效利用提供科学参考.[方法]以'灿烂'乡铃'园蓝'昂丝萝'顶峰'5个适宜湖南种植的兔眼蓝莓品种果实为材料,采用直接测量法对5个品种蓝莓的品质特征(单果质量、含水量、硬度、总酸、可溶固形物、固酸比)进行测定,采用分光光度法测定果实的抗氧化物质含量(总酚、总黄酮、总花色苷)和抗氧化能力(DPPH自由基清除能力、ABTS自由基清除能力),采用HPLC对果实中多酚组成进行分析.[结果]5个蓝莓品种的果实品质特征、抗氧化物质含量、抗氧化能力和多酚组成均有显著性差异.'灿烂'和'园蓝'果实较大,单果质量分别为1.72±0.07和1.14±0.08 g,固酸比较高,分别为6.33±0.37和5.09±0.10,3种抗氧化物质含量明显低于其他3个品种,它们的DPPH和ABTS自由基清除率分别为38.80±1.87％和40.51±0.38％以及40.11±1.02％和40.93±0.96％,抗氧化能力明显较弱,因此适合鲜食.'乡铃'和'昂丝萝'固酸比分别为4.49±0.45和4.80±0.11,含水量较低,分别为81.74±0.16％和82.40±0.24％,3种抗氧化物质含量分别为4.12±0.06 mg GAE/g、0.61±0.03 mg RE/g和1.09±0.03 mg/g以及3.73±0.14 mg GAE/g、0.97±0.02 mg RE/g和0.92±0.02 mg/g,抗氧化物质含量和抗氧化能力在5个品种中均为中等,因此既适合鲜食也适合果干类食品加工.'顶峰'固酸比适中但含水量高达83.20±0.15％,果实中3种抗氧化物质含量较高,分别为4.63±0.13 mg GAE/g、0.72±0.02 mg RE/g和1.15±0.11 mg/g,DPPH和ABTS自由基清除率分别为50.39±0.37％和50.99±1.29％,抗氧化能力明显强于另外4个品种,因此'顶峰'适合果汁类功能食品加工.HPLC结果表明蓝莓果实中至少含有12种多酚,其中绿原酸和表儿茶素是含量最高的2种多酚,含量分别在45.77％和4.22％以上.'灿烂'果实中的多酚组成最为复杂,至少有12种,'园蓝'果实中仅检测出绿原酸和表儿茶素.[结论]不同蓝莓品种的品质特征、抗氧化物质含量、抗氧化能力和多酚组成有显著性差异,因此可以根据不同需要选择不同的品种进行种植,对于消费水平高、鲜食蓝莓需求量大的地域和旅游区附近可适量加大推广'灿烂'和'园蓝'蓝莓种植面积,对鲜食蓝莓需求量少、以深加工为主的地域可推广种植种'乡铃'昂丝萝'和'顶峰'.

[目的]研究观赏桃在湖南省长沙地区的观赏特性及其价值,为长沙地区引种栽培桃花提供科学依据.[方法]调查了湖南省森林植物园桃花园中18个观赏桃品种的花期物候期及其花色、花量、花瓣数、花冠直径(盛开时花朵自然张开的直径)、雄蕊、雌蕊、萼片数等观赏性指标,采用层次分析法对相关观赏性指标进行赋分评价.[结果]18个观赏桃品种的花色丰富,其花色有红色、粉色、白色、白粉相间和红粉相间等;在18个观赏桃品种中,‘北京紫’的观赏期最早,其于2月底便进入初花期,而‘红碧桃’的观赏期最晚,其于3月20日才进入初花期,两者前后相差20余d;‘瑞红’的花期最短,只有15 d,而‘元春’的花期最长,为25 d,整个园内桃花的观赏期接近40 d;‘人面桃’的花量最大,在长为50 cm的花枝上着生的花朵数量平均为34.8朵,而‘瑞红’的最少,全株仅有25朵花;‘迎春桃’的花冠直径最大,平均为52.5 mm;‘红碧桃’的花瓣数最多,平均为66枚;‘晚白’的雄蕊数最多,平均为53.1枚;‘人面桃’的雌蕊数最多,平均达到3.03枚;‘红碧桃’的萼片数最高,平均为11.37片.综合评价得分中,‘人面桃’‘元春’‘粉红女孩’‘红碧桃’排名前四,其得分分别为42、42、40和40分,其表现均优;而‘北京紫’‘照手桃’‘瑞红’的得分分别为29、28和26分,其表现均较差.[结论]‘人面桃桃’‘元春’‘粉红女孩’‘满天红’等16个品种在湖南省长沙地区均具较高的观赏性和适应性,可进一步利用;而‘瑞红’和‘绯桃’的表现均较差,在湖南省长沙地区造景造园时应慎用这两个品种.

Sphingolipids and their intermediates play multiple roles in biological processes. The sphingoid long-chain base component of sphingolipids has emerged as a participant in the regulation of plant biotic and abiotic stress responses. The phytohormone abscisic acid (ABA) regulates many stress responses in plants for environmental adaptation. However, the relationship between the sphingoid bases and ABA is undetermined. In this study, mhp1-1 (the yeast Mpo1 homolog in plants) was isolated through a sodium chloride (NaCl)-sensitivity screen of Arabidopsis transfer DNA (T-DNA) insertion mutants. mhp1-1 was hypersensitivity to salt/osmotic stress and ABA. MHP1 encodes a protein with a domain of unknown function 962 (DUF962). Endoplasmic reticulum-localized MHP1 was found to interact with ABI1. MHP1, a homolog of yeast dioxygenase Mpo1, rescued the growth arrest of mpo1Δ cells caused by ER stress, suggesting functional homology of MHP1 to Mpo1. Overall, MHP1 plays important roles in response to ABA.

To provide a scientific basis for the conservation and exploitation of wild Cerasus species in Dawei Mountain, we investigated the community characteristics and species diversity of Cerasus species. The results showed that there were four Cerasus communities, C. campanulata, C. diel-siana, C. conradinae and C. xueluoensis, in Dawei Mountain. Phaenerophyte in the life form and pantropical elements in the local flora were both dominant. The shrub layer had higher species diversity than that of the arbor layer. Species diversity of those four communities was following the order of C. dielsiana, C. conradinae, C. campanulata and C. xueluoensis. The community structure was relatively stable when young and mature individuals of Cerasus predominated. The ground dia-meter class structure indicated that the C. xueluoensis population was a growing population with a typical pyramid structure. The C. conradinae community was mono-dominated by C. conradinae, with C. dielsiana and C. campanulata as the important companion species. Those three Cerasus species would be replaced by other coniferous and broadleaved species due to the shortage of natural regeneration.