中国苏铁属植物资源和保护

苏铁类植物含2科10属, 是现存种子植物最原始的类群之一, 具有重要的科学研究和保护价值。苏铁属(Cycas)是唯一在中国有自然分布的苏铁类植物, 约20种, 多数种类为中国特有。中国的苏铁属植物主要分布于西南地区和东南沿海, 大部分种类为狭域分布的类群, 其生存繁衍受到了严重的威胁, 均被列为国家一级重点保护野生植物。基于文献资料收集整理和野外调查, 本文对中国苏铁属植物的研究和保护进行了阶段性总结。介绍了中国苏铁属植物分类研究、地理分布; 阐述了中国苏铁植物生存面临的主要威胁及相应的保护措施, 提出了保护方案的制定应遵循遗传学特征等科学依据。文中总结了我国苏铁植物保护科研工作中存在的5个主要问题: (1)苏铁植物基础科学问题有待进一步研究, (2)苏铁植物生境破坏较为严重, (3)人为盗采贩卖依然猖獗而苏铁植物园林园艺育种事业却举步不前, (4)苏铁自身生物学特性导致繁殖困难, (5)迁地保护难以保证苏铁种质“纯洁性”等, 同时针对这些问题提出相应建议, 以期为我国苏铁属植物的研究、保护以及可持续利用工作提供参考。     

L312, a novel PPARγ ligand with potent anti-diabetic activity by selective regulation

Background

Selective PPARγ modulators (sPPARγM) retains insulin sensitizing activity but with minimal side effects compared to traditional TZDs agents, is thought as a promising strategy for development of safer insulin sensitizer.

Methods

We used a combination of virtual docking, SPR-based binding, luciferase reporter and adipogenesis assays to analyze the interaction mode, affinity and agonistic activity of L312 to PPARγ in vitro, respectively. And the anti-diabetic effects and underlying molecular mechanisms of L312 was studied in db/db mice.

Results

L312 interacted with PPARγ-LBD in a manner similar to known sPPARγM. L312 showed similar PPARγ binding affinity, but displayed partial PPARγ agonistic activity compared to PPARγ full agonist pioglitazone. In addition, L312 displayed partial recruitment of coactivator CBP yet equal disassociation of corepressor NCoR1 compared to pioglitazone. In db/db mice, L312 (30 mg/kg·day) treatment considerably improved insulin resistance with the regard to OGTT, ITT, fasted blood glucose, HOMA-IR and serum lipids, but elicited less weight gain, adipogenesis and hemodilution compared with pioglitazone. Further studies demonstrated that L312 is a potent inhibitor of CDK5-mediated PPARγ phosphorylation and displayed a selective gene expression profile in epididymal WAT.

Conclusions

L312 is a novel sPPARγM.

General significance

L312 may represent a novel lead for designing ideal sPPARγM for T2DM treatment with advantages over current TZDs.     

黄瓜果瘤的遗传及SSR标记

通过对以荷兰温室无瘤黄瓜(Cucumis sativus)品种Z1和Z3为母本(tutu),有瘤黄瓜品系东农129为父本(TuTu)的杂交后代F1和F2的统计分析,结果表明:在F1代,2个组合果实都有果瘤,有果瘤为显性;F2代果实有瘤与无瘤呈现分离,其比例分别是2．92:1和2．95:1,表明Tu基因是独立遗传的,即有瘤(Tu)对无瘤(tu)为显性。为了获得与黄瓜果瘤基因连锁的SSR(simple sequence repeat)标记,从129×Z3 F2群体中选取有瘤、无瘤单株的DNA各10个,构建有瘤、无瘤近等基因池。用86对SSR引物在亲本及DNA混合池之间进行筛选,并对F2群体的75个单株进行验证。筛选得到了5对与果瘤相关的SSR引物,经MAPMAKER／EXP version 3．Ob软件分析,其中CSWGATT01B、CSWGATT01C、CSCT335和CSWGATT01A四个标记位于同一连锁群上,Tu基因位于这4个标记构建的连锁群中,具体位置为CSWGATT01C-Tu-CSCT335,距离两侧标记的遗传距离分别为20．0 cM和14．1 cM。     

农业生态系统养分循环再利用的作物产量增益

在辽西褐土上进行8年的田间试验结果表明,在不同化肥基础上,每年以60％的收获产品堆腐后循环回田,平均分别可获得29．6％（不施化肥）、15．2％（N肥）、11．1％（NP肥）和9．2％（NPK肥）的增产率,或分别每年增产粮食1.33、0．99、0．79、0．64t·hm－2．养分循环再利用的作物增产效益在试验的8年中有着逐年增长趋势,表明以堆肥形式循环回田养分对作物的增产作用存在着明显的残效叠加效应,因此,只有通过长期田间试验方能准确评估农业系统中养分循环再利用的作物产量增益．     

Genome-wide investigation on the genetic variations of rice disease resistance genes

Exploitation of plant disease resistance (R) gene in breeding programs has been proven to be the most efficient strategy for coping with the threat of pathogens. An understanding of R-gene variation is the basis for this strategy. Here we report a genome-wide investigation on the variation of NBS-LRR-encoding genes, the common type of R genes, between two sequenced rice genomes, Oryza sativa L. var. Nipponbare and 93–11. We show that the allelic nucleotide diversity in 65.0% of 397 least-divergent pairs is not high (0.344% on average), while the remaining 35% display a greater diversity (5.4% on average). The majority of conserved R genes is single-copy and/or located as a singleton. The clustered, particularly the complex-clustered, R-genes contribute greatly to the rich genetic variation. Surprisingly only 11.2% of R-genes have remarkably high ratios of non-synonymous to synonymous rates, which is much less than the 17.4% observed between Arabidopsis genomes. Noticeable “artificially selective sweeping” could be detected in a large proportion of the conserved R-genes, a scenario described in the “arms race” co-evolutionary model. Based on our study, a variation pattern of R-genes is proposed and confirmed by the analysis of R-genes from other rice lines, indicating that the observed variation pattern may be common in all rice lines.Electronic Supplementary Material Supplementary material is available for this article at     

光合细菌利用工业有机废水产生5-氨基乙酰丙酸

[目的]利用本实验室筛选的5-氨基乙酰丙酸(5-aminolevulinic acid,ALA)高产紫色非硫红假单胞菌株,以味精、柠檬酸、啤酒和豆制品生产废水作为底物,进行光合细菌利用废水产生ALA并去除化学需氧量(CODcr)的研究.[方法]光合细菌培养温度为30℃,光照强度为3000 Lux,进行乙酰丙酸、甘氨酸、琥珀酸的添加与否和废水灭菌与否的处理,用比色法测定菌液光密度,ALA检测采用Ehrlich'S试剂分光光度检测法.[结果]在不添加乙酰丙酸(levulinic acid,LA)、甘氨酸和琥珀酸的条件下,菌株99-28的菌体生长在72～96 h达到稳定期,ALA产量在96h最高,在4种废水中,味精废水的ALA产量最高,CODcr去除率也最高;添加LA、甘氨酸和琥珀酸显著提高ALA产量,但CODcr去除效果不好.废水不灭菌略微降低99-28菌株的生长和CODcr的去除能力,在添加LA、甘氨酸和琥珀酸的条件下的,ALA产量明显下降.ALA高产突变菌株L-1在有机废水中的生长状况、对有机废水的CODcr去除与菌株99-28表现一致,在不添加和添加LA、甘氨酸和琥珀酸的条件下,突变株L-1的ALA产量明显比菌株99-28高.[结论]本实验室筛选的紫色非硫红假单胞菌株能利用有机废水作为底物产生ALA并降解CODcr.     

臭氧对微生物杀菌作用的初步研究

以稀释平板计数法 ,测定了臭氧对水体和空气环境的消毒杀菌作用。结果表明 :随着臭氧浓度 (时间 )的增加 ,对各类微生物杀灭率明显上升 ,除了芽孢杆菌外 ,杀灭率可以达到 1 0 0 %。     

白桦半同胞家系苗期生长和光合特性及其选育评价指标筛选

对6个白桦半同胞家系苗期生长、光合和叶绿素荧光参数进行测定,分析各指标的变异状况,并探讨白桦苗期选育评价的主要因子。结果表明:(1)白桦半同胞家系间生长性状(苗高、地径、叶片长度、叶片宽度、叶片数量、叶片长宽比)和光合指标(Pn、Gs、Ci、Tr、WUE)差异极显著,除Ci外各光合指标的变异系数和遗传变异系数均超过了10%。(2)白桦半同胞家系间叶绿素荧光参数F0、F0′、Fs、Fv′/Fm′、NPQ和Yield差异显著,除NPQ外所有叶绿素荧光参数变异系数和遗传变异系数均不超过10%,表明白桦半同胞家系叶片光合潜在能力差异不大。(3)白桦半同胞家系叶绿素荧光参数各指标遗传力H2均大于0.4,属中度遗传力,而生长指标和光合指标遗传力均大于0.7,属于较高遗传力,表明白桦半同胞家系生长和光合变异主要由遗传因素控制,有利于苗期选择评价。(4)白桦半同胞家系苗高、地径与WUE显著正相关,而与Yield显著负相关;叶片数量和叶片宽度对白桦苗期苗高和地径影响较大,可以作为苗期选择评价的主要因子。