极危孑遗蕨类中华水韭叶结构的系统学意义

水韭属是濒危的孑遗植物,是研究古生态及其物种演化的活化石。本文用扫描电子显微镜和透射电子显微镜观察了中华水韭叶片的结构特征,首次报道了:(1)通气道横隔细胞在同一平面以5~7个放射状短臂相互连接,且细胞表面有数百个微纤毛;(2)叶表皮为复表皮;(3)光合细胞以5~7个短臂在3D空间相互连接;(4)叶脉不分支,管胞的环纹与初生壁间另有连接结构,管胞周围有薄壁细胞紧密包围;(5)舌足与叶肉嵌合处各有表皮;(6)自气孔下室观察了气孔器的内侧结构,为气孔研究拓展了视野。认为水韭属叶片的超微3D结构具有稳定的特殊性和复杂性,与近源的石松科及卷柏科相差甚远,证明水韭有孤立的演化路线。     

混凝土结构物与植物叶片之红外热像侦测研究

红外热像仪准确量测温度的主要关键为物质的发射率.红外热像仪常用于战区侦测,但战区目标物常以植物绿化达到伪装效果.为此基于能量平衡法则,建立叶片发射率仿真模型,可用以估算叶片发射率.另外以红外热像仪分析±0.5℃微小温差环境中混凝土结构物与植物叶片之红外热影像,实验结果显示两种目标物红外热像平均温度与红外热像仪发射率参数设定值的回归直线相当接近,但两种目标物平均温度标准误差与红外热像仪发射率参数设定值的回归直线明显不同.混凝土与叶片具有不同的红外热像性质,此一发现将有助于提升红外热像仪对微小温差目标区的侦测能力.     

黑龙江苹果亚科植物叶表皮形态结构的研究

利用扫描电子显微镜对黑龙江苹果亚科14种植物叶表皮微形态进行比较研究。结果显示:(1)叶表皮细胞呈多边形或无规则形,垂周壁式样呈平直或弓形、浅波纹、深波纹;(2)除无毛花楸无表皮毛外,其它均具有表皮毛,类型均为单细胞不分支非腺毛;(3)叶表皮纹饰呈均匀分布蜡质纹饰和仅气孔周围有蜡质条纹;(4)气孔器均在下表皮分布,且气孔器类型为轮列型、无规则型或不典型辐射型;气孔外拱盖为单层或双层,内缘近平滑或不规则波状;保卫细胞两极仅在水榆花楸、毛山楂、黑果栒子和全缘栒子中出现"T"型加厚。研究表明,该亚科下5属间的叶表皮微形态特征存在一定差异,属内种间在气孔器、表皮毛以及表皮纹饰特征上存在一致性,为属间的系统分类和演化提供了形态结构的依据。     

植物叶片厚度日变化及其与生态因子相关性的研究

多数植物的叶片很薄、很软、充满水分,对其组织结构的研究主要集中在显微结构和亚显微结构方面.利用自主研发的YI-20010A型植物叶片厚度精密测量仪,对几种温室栽培的植物叶片进行监测,可以直接获得叶片厚度的实时变化情况.供试的5种植物叶片都在正午前后出现叶片厚度一天中的最低值.对番茄和高羊茅叶片厚度与相同时段的叶片附近的光照强度、空气温度、相对湿度三个周期性变化的生态因子的相关性进行分析,得出叶片厚度变化与光照强度有显著的负相关,与相对湿度呈显著的正相关.     

The Conserved and Specific Roles of the LUX ARRHYTHMO in Circadian Clock and Nodulation

LUX ARRHYTHMO (LUX) plays a key role in circadian rhythms and flowering. Here, we identified the MtLUX gene which is the putative ortholog of LUX in Medicago truncatula. The roles of MtLUX, in both the nodulation belowground and leaf movement aboveground, were investigated by characterizing a loss-of-function mtlux mutant. MtLUX was required for the control of flowering time under both long-day and short-day conditions. Further investigations showed that the early flowering in the mtlux mutant was correlated with the elevated expression level of the MtFTa1 gene but in a CO-like independent manner. MtLUX played a conserved role in the regulatory interactions with MtLHY, MtTOC1, and MtPRR genes, which is similar to those in other species. Meanwhile, the unexpected functions of MtLUX were revealed in nodule formation and nyctinastic leaf movement, probably through the indirect regulation in MtLHY. Its participation in nodulation is of interest in the context of functional conservation and the neo-functionalization of the products of LUX orthologs.     

Rosmarinic Acid,as an NHE1 Activator,Decreases Skin Surface pH and Improves the Skin Barrier Function

Stratum corneum (SC) pH regulates skin barrier functions and elevated SC pH is an important factor in various inflammatory skin diseases. Acidic topical formulas have emerged as treatments for impaired skin barriers. Sodium proton exchanger 1 (NHE1) is an important factor in SC acidification. We investigated whether topical applications containing an NHE1 activator could improve skin barrier functions. We screened plant extracts to identify NHE1 activators in vitro and found Melissa officinalis leaf extract. Rosmarinic acid, a component of Melissa officinalis leaf extract, significantly increased NHE1 mRNA expression levels and NHE1 production. Immunofluorescence staining of NHE1 in 3D-cultured skin revealed greater upregulation of NHE1 expression by NHE1 activator cream, compared to vehicle cream. Epidermal lipid analysis revealed that the ceramide level was significantly higher upon application of the NHE1 activator cream on 3D-cultured skin, compared to application of a vehicle cream. In a clinical study of 50–60-year-old adult females (n = 21), application of the NHE1 activator-containing cream significantly improved skin barrier functions by reducing skin surface pH and transepidermal water loss and increasing skin hydration, compared to patients who applied vehicle cream and those receiving no treatment. Thus, creams containing NHE1 activators, such as rosmarinic acid, could help maintain or recover skin barrier functions.     

麻纤维在汽车用装饰材料中的应用

本文介绍麻纤维的优良性能及其在汽车装饰材料中的应用及前景展望。     

Selectively fluorinated analogs reveal differential olfactory reception and inactivation of green leaf volatiles in insects

The role of the alkyl terminus of green leaf volatile (GLV) molecules in olfactory reception and inactivation was examined in three diverse insect species: the beet armyworm,Spodoptera exigua (Lepidoptera); the Colorado potato beetle,Leptinotarsa decemlineata (Coleoptera); and the desert locust,Schistocerca gregaria (Orthoptera), using selectively fluorinated analogs of GLVs and electroantennograms (EAGs). When only the magnitude of the depolarization of the EAG is considered (a measure of reception), the order of effectiveness was 1-hexanol (6:OH)=(Z)-3-6:OH > 5,5,6,6,6-pentafluoro-(Z)-3-6:OH =5,5-difluoro-(Z)-3-6:OH 5,5,6,6,6-pentafluoro-6: OH. Percent recovery of the EAG (a measure of inactivation) was greater for the pentafluoro-(Z)-3-6: OH analog than for the difluoro-(Z)-3-6: OH analog. Our results show that the alkyl end of GLV molecules plays an important role not only in reception, but also inactivation processes in insect olfaction. Furthermore, specificities of these two processes may differ.Research conducted by J.C.D. while on an ARS Fellowship at IPO-DLO.