Plants being sessile organisms are often exposed to various abiotic stress conditions, which greatly hamper the growth, yields as well as the quality of produce. Plants respond to abiotic stresses in an exceptionally complex and coordinated manner, involving the interactions and crosstalk with many metabolic-molecular pathways. One of the most common responses is generation of reactive chemical species including reactive oxygen species (ROS), reactive nitrogen species (RNS), reactive carbonyl species (RCS) and reactive sulfur species (RSS). ROS and RNS have long attracted attention from the plant researchers for both their damaging as well as protective effects. However, several reports are emerging to confirm similar roles played by the relatively newer 'reactive' members, the RCS and RSS. Plant reactive species are also hailed as vivacious signaling molecules that play regulatory roles in many plant metabolic procedures. Undeniably, these reactive species are involved in virtually all aspects of plant cell functions. Reactive species and the antioxidant machinery maintain a delicate but critical cellular redox-balance which gets disturbed under stress conditions, where their biosynthesis, transportation, scavenging and the overall metabolism gets decisive for plant survival. The current review aims to highlight and discuss the role of ROS, RNS, RCS, and RSS in plants especially under abiotic stresses, cross-talks between them, current approaches and technological advents for their characterization, and a perspective view on exploration/manipulation of the pathways and check-points involved in biosynthesis, transport and scavenging of these reactive species for engineering abiotic stress tolerant crop plants.

Polymethylene-interrupted polyunsaturated fatty acids (PMI-PUFAs) are emerging functional lipids with proven antioxidant and anti-inflammatory effects. In this study, a typical PMI-PUFA, sciadonic acid (C20:3, 5c 11c 14c), was enriched in the kernel oil of Torreya fargesii (T. fargesii) by fractionation. Fractionated kernel oil of T. fargesii (containing 25% sciadonic acid) showed equal stability and similar radical scavenging ability compared with the non-fractionated oil. In anti-inflammatory tests, fractionated kernel oil was shown to inhibit the activity of phosphodiesterase (PDE-5, efficiency 80% at 133.7 mug/mL) and lipoxygenase-5 (LOX-5, efficiency 65% at 66.7 mug/mL) more effectively than the non-fractionated oil. This shows that increasing the amount of sciadonic acid can enhance the anti-inflammatory effect of the kernel oil. This research also indicates that fractionation is a feasible way to obtain sciadonic acid-rich functional oil with potential pharmacological effects.

为揭示不同海拔巴山榧树居群的遗传多样性水平,实验利用ISSR分子标记对四川花萼山4个不同海拔（1 000 m, 1 200 m, 1 450 m, 1 700 m）巴山榧树居群的遗传多样性和遗传分化进行分析。结果表明,巴山榧树在物种水平上多态性位点百分率为77.84%,Nei’s基因多样性指数（H）和Shannon’s信息指数（I）分别为0.249 3和0.375 2,反映出巴山榧树保持有较高的遗传变异。巴山榧树在居群水平上仍具有较高的遗传多样性,平均多态性位点百分率为54.04%,H和I均值分别为0.176 2和0.266 1。4个居群的遗传多样性总体上随着海拔的升高而增加,遗传多样性与海拔高度呈不显著的正相关（p＞0.05）。4个居群间的基因分化系数（Gst）为0.293 2,表明该地区巴山榧树居群的遗传分化程度较高,有29.32%的遗传变异位于居群间,70.68%的变异位于居群内。4个居群间的基因流（Nm）为1.205 1,较低的基因流可能是导致巴山榧树居群间遗传分化程度较高的重要因素。4个居群间的遗传距离介于0.073 2～0.197 9之间,遗传距离随着海拔高度差的增加总体呈现逐渐增大的趋势。上述结果有助于研究巴山榧树遗传资源的保护与利用。

The hydrosoluble extract from a processing waste, aril of Torreya fargesii Franch. (abbr.as Torreya F), was investigated for its antioxidative properties and resulting protective effect on the oxidation of DHA (docosahexaenoic acid) algal oil. The aril extract of Torreya F contained about 125.2 mg GAE/g dry extract total polyphenols and 18.5 mg RT/g dry extract total flavonoids. The scavenging ability on the DPPH (1,1-diphenyl −2-picrylhydrazyl), hydroxyl and superoxide anion radicals of aril extract of Torreya F was stronger than that of commercial ascorbyl palmitate. With the addition of Torreya F aril extract, the increasing peroxide value and acid value of DHA algal oil was inhibited both in the long-term storage test and the accelerating Schaal test.
© 2018 The Author(s).

为探讨不同处理对巴山榧树扦插生根的影响,分别研究了基质种类、插穗类型、生根剂不同质量浓度配比及处理时间对巴山榧树扦插生根的影响。结果表明,不同基质对巴山榧树插穗的生根率、生根数和根长的影响极显著,1年生枝条插穗经1 000 mg/L ABT1处理30 min后,扦插于V（泥炭土）∶V（蛭石）∶V（园土）=3∶1∶1混合基质中的生根率最高,达51.13%;不同插穗类型对生根率和生根数的影响差异达到极显著水平,1年生插穗的生根率明显高于2年生插穗,3年生插穗不生根,2年生插穗的生根数略高于1年生插穗;正交试验显示处理时间和ABT1浓度2个试验因素对巴山榧树插穗生根率的影响达到显著水平,IBA浓度对生根率的影响则不显著,经1 000 mg/L ABT1和200 mg/L IBA处理40 min的插穗生根效果最好,生根率达75.56%。该试验为巴山榧树扦插育苗技术的深入研究提供了参考依据,为巴山榧树快速繁育和推广应用提供了科学依据。

以2年生巴山榧树幼苗为试材,采用常规石蜡切片方法和光学显微技术,研究了巴山榧树根、茎、叶的解剖结构,以期为巴山榧树的深入研究与保护利用提供参考依据。结果表明:2年生巴山榧树幼苗根的结构由周皮、次生维管组织和初生木质部组成;根内无髓部和树脂道;次生韧皮部中无石细胞。茎的结构由周皮、皮层、次生维管组织、初生木质部和髓组成;木质部中无树脂道,有少量木薄壁组织细胞;木射线单列。叶片结构由上下表皮、叶肉组织和叶脉组成;表皮细胞壁显著增厚,具角质层;气孔仅分布于下表皮,下表皮气孔带区域具有分叉的角质钉;叶肉组织分化为栅栏组织和海绵组织,叶肉中具有分枝状石细胞;维管束1条,在维管束的远轴面内生树脂道1个,泌脂细胞2~3层。

为揭示巴山榧树遗传多样性在时间尺度上的变化规律,根据胸径大小将四川省花萼山国家级自然保护区巴山榧树群体划分为幼苗、小树和成树3个世代,利用ISSR分子标记技术对3个世代共70个个体的遗传多样性及遗传分化进行了分析。10条ISSR引物扩增共检测到125个多态位点,多态位点百分率为74.85%,表明花萼山巴山榧树群体具有较高的遗传多样性。ISSR分析显示3个世代的多态位点百分率、Shannon’s信息指数（I）和Nei’s基因多样性指数（H）均以成树最高,幼苗最低,幼苗的遗传多样性指数低于小树和成树,表明花萼山巴山榧树种群世代间的遗传多样性呈下降趋势。巴山榧树3个世代间的基因分化系数Gst=0.109 8,基因流Nm=4.053 7。3个世代间的遗传一致度以幼苗与小树间最大,遗传距离则以幼苗与小树间最小。上述研究结果为深入研究巴山榧树遗传资源和制定有效的保护措施提供了科学依据。

A multifunctional composite of graphene (Gr), polydopamine (Pdop) and Ag nanoparticles (Ag NPs) was synthesized through a facile and gentle method, where Pdop was immobilized on Gr easily at room temperature and Au NPs was subsequently deposited through gently stirring. The electrochemical responses were investigated at the electrode modified with the composite of Ag, Pdop and Gr by sulforaphane acting as the model molecule. The results indicated that the electrode modified with Ag-Pdop-Gr composite exhibited remarkably favourable for the electron transfer kinetics compared to the glassy carbon electrodes modified with Gr or Ag NPs. At last, the proposed was applied into the simultaneous determination of sulforaphane of trace level in the specimens of carmine radish.

In the present work, a voltammetric sensor for detection of caffeine was prepared by modifying a glassy carbon electrode with Nafion and PDDA-MWCNT. This sensor shows high sensitivity for caffeine determination in the range from 0.3 to 80 mu M, and the detection limit is 0.05 mu M. Moreover, the sensor exhibits good stability, reproducibility and high activity for electrochemical oxidation of caffeine. Thus, it is available for the quantitative analysis of caffeine in Oolong tea.

为了掌握中国特有裸子植物巴山榧树的种群现状,预测种群数量动态趋势,以分布于重庆、四川、陕西、湖北、安徽、河南和甘肃等省市的15个地点的残存巴山榧树种群为对象,建立巴山榧树种群径级结构和高度级结构图,编制种群静态生命表,绘制种群存活曲线、死亡率和消失率曲线,同时结合谱分析方法分析种群数量动态变化。结果表明:巴山榧树种群密度较低,平均为5.33株/100m~2,其中神农架种群（SN）密度最高,为9.58株/100m~2,城口种群（CK）密度最低,为2.75株/100m~2。径级结构中低龄级个体占有较高的比例,种群表现为增长型年龄结构;不同局域种群的径级结构差异明显,除宝兴种群（BX）外,其余种群的径级分布不完整。高度级结构中低于6m的个体占88.74%,绝大多数个体处于群落灌木层。种群的生命期望在不同龄级间波动明显,第3、7龄级的生命期望较低。巴山榧树种群存活曲线趋于Deevey-Ⅲ型;死亡率曲线和消失率曲线变化趋势一致,均在第3、7龄级出现峰值。巴山榧树种群的数量动态除受基波的影响外,在3、5、7龄级还显示出明显的小周期波动。巴山榧树为长寿命孑遗植物,呈岛屿化斑块分布,种群规模小,自然更新能力差,面临灭绝的危险,应及时加以保护。