‘72杨’韧皮部的构造与理化性能

将‘72杨’、杉木和毛竹的木质部进行对比试验,观察并测试‘72杨’韧皮部的解剖构造以及理化特性,为其高值化利用提供基础数据。使用场发射环境扫描电镜、X射线衍射仪、傅里叶变换红外光谱仪等设备和NREL标准对‘72杨’韧皮部的微观结构、结晶度、化学成分等物化性质进行测定与分析。研究结果表明,‘72杨’韧皮部中韧皮薄壁细胞和筛管分子占细胞总面积的(81.9±1.8)%,结构相对简单。‘72杨’韧皮部气干密度为0.358 g/cm3,绝干密度为0.321 g/cm3;而木质部的相应密度较高,分别为0.497和0.482 g/cm3;‘72杨’韧皮部结晶度仅为19.4%,比木质部低8.7%。‘72杨’韧皮部纤维素、半纤维素、木质素的含量分别为28.7%,11.1%,24.1%,均低于木质部中相应成分的含量,且木质化程度低,半纤维素以木糖为主。此外,由红外谱图发现‘72杨’韧皮部含有单宁、酚类、胼胝质等物质。‘72杨’韧皮部具有低密多孔、结构疏松、结晶度低、木质素含量低、抽提物含量高等特点。因此,‘72杨’韧皮部特别有利于机械(能耗低)或化学(抗降解屏障低)降解以及物化改性(多孔、可及性强),可提取酚类、单宁、胼胝质等物质用于工业应用,研究结果可为‘72杨’韧皮部的高值化利用提供重要的理论依据。     

Vectorizing agrochemicals: enhancing bioavailability via carrier‐mediated transport

Systemicity of agrochemicals is an advantageous property for controlling phloem sucking insects, as well as pathogens and pests not accessible to contact products. After the penetration of the cuticle, the plasma membrane constitutes the main barrier to the entry of an agrochemical into the sap flow. The current strategy for developing systemic agrochemicals is to optimize the physicochemical properties of the molecules so that they can cross the plasma membrane by simple diffusion or ion trapping mechanisms. The main problem with current systemic compounds is that they move everywhere within the plant, and this non‐controlled mobility results in the contamination of the plant parts consumed by vertebrates and pollinators. To achieve the site‐targeted distribution of agrochemicals, a carrier‐mediated propesticide strategy is proposed in this review. After conjugating a non‐systemic agrochemical with a nutrient (α‐amino acids or sugars), the resulting conjugate may be actively transported across the plasma membrane by nutrient‐specific carriers. By applying this strategy, non‐systemic active ingredients are expected to be delivered into the target organs of young plants, thus avoiding or minimizing subsequent undesirable redistribution. The development of this innovative strategy presents many challenges, but opens up a wide range of exciting possibilities. © 2018 Society of Chemical Industry     

缺铁黄瓜地上部对根系适应性反应的调节

用营养液培养方法研究了黄瓜地上部对根系缺铁适应性反应的调节。缺铁导致植株根系Fe     

Stem growth during seed production in soybean: Implications for pod yield

In soybean (Glycine max (L.) Merr.), stems remain a competitive carbon resource sink during reproduction. Radial stem expansion after termination of axial stem growth requires resources to produce secondary cell walls in secondary vascular tissues. The impact of both the timing and extent of secondary growth in stems on fruit production in soybean is unknown. We hypothesized that cultivars gaining higher amounts of secondary vascular tissues during seed filling would experience lower reproductive output. Four determinate cultivars were grown in a greenhouse and harvested at the beginning and ending of seed filling for biomass determination and tissue composition measurement (ImageJ-Fiji). Cultivar ‘Hanover’ entered seed filling with the lowest amount of secondary phloem. It produced the largest increase in radial stem expansion, largest seeds, and fewest undeveloped (aborted) fruits. The physiological role of active secondary phloem production in stems for seed production in soybean reproduction is unclear. We reject our initial hypothesis and propose that high fitness may require the concomitant growth of vegetative and reproductive organs.     

适于苹果韧皮部提取蛋白质的方法

利用TCA/丙酮沉淀法、直接提取法和两种改良的Tris-HCl提取法对苹果实生树的韧皮部提取蛋白质,并用SDS-PAGE和银染显色的方法对提取的蛋白质结果进行比较,发现：用经过浓缩的的Tris-HCl改良法提取的蛋白质条带清晰,数量多,方法简单且杂质干扰少。因此浓缩的Tris-HCl改良法是适用于苹果韧皮部蛋白质提取的最佳方法。     

灵武长枣果实韧皮部后糖分运输生理特征研究

为探讨灵武长枣果实韧皮部后糖分运输生理机制,以不同发育时期灵武长枣果实为试材,探讨载体抑制剂PCMBS和ATP酶抑制剂(EB、DNP、NO_3~-)对果实韧皮部非维管束区吸收~(14)C-葡萄糖和~(14)C-蔗糖的影响。结果表明,在缓慢生长期S1、第1次快速生长期R1和第2次快速生长期R2,PCMBS和ATP酶抑制剂处理明显抑制了果实对~(14)C-葡萄糖的吸收;而在缓慢生长期S2,抑制作用不明显。~(14)C-葡萄糖跨膜运输至液泡的能力大小依次为R2S1R1S2。在第2次快速生长期R2和缓慢生长期S3,PCMBS和ATP酶抑制剂处理对果实吸收~(14)C-蔗糖影响明显,但不同发育时期抑制果实对~(14)C-蔗糖吸收的程度不同。R2和S3时期,~(14)C-蔗糖跨质膜和液泡膜运输积累的能力均较强。由此可见,在S1、R1、R2、S3时期,灵武长枣果实糖卸出后的运输是需要载体并与ATP酶相偶联的主动运输过程;在S2时,果实糖分的运输同时存在主动运输和被动运输2个过程。该研究可为灵武长枣果实糖分积累和品质调控奠定基础。     

云南沉香和白木香的木材结构比较解剖学研究

通过显微和亚显微解剖观察方法,对云南沉香和白木香的木材结构进行初步研究。结果表明,云南沉香的木材由内函韧皮部、木射线、管孔、木纤维等组成。内函韧皮部呈岛式均匀分布,可见大量的长方体晶体;管孔以复管孔、单管孔的形式存在;木射线为异性Ⅲ型。说明云南沉香与白木香的木材结构基本一致。     

Investigations on the inheritance of color and carotenoid content in phloem and xylem of carrot roots (Daucus carota L.)

Summary Investigations on the inheritance of root color in carrot (Daucus carota L.) were carried out by crossing uniformly colored roots to various tinge type roots, i.e. roots of which the xylem differs in color from the phloem.A single major gene (Y) was found to be responsible for the observed differences in progenies of orange x tinge orange-white (orange referring to phloem color, white to xylem color) crosses. Plants carrying the dominant Y-allele had either white or tinge orange-white roots, whereas plants with orange roots were of the genotype yy. Similarly one major gene (Y ₂) determined the segregation found in progenies of orange x yellow crosses. In the latter crosses, plants having the dominant Y ₂-allele had either yellow or tinge orange-yellow roots while the recessive would be orange. Variation in phloem color, i.e. differences between white and tinge orange-white or between yellow and tinge orange-yellow, was apparently caused by minor genes, modifiers, gene interactions, or by genes that are not involved in carotenogenesis in a direct way.When both the Y- and Y ₂-genes were present, the roots were always white. Usually white roots gave a digenic segregation pattern in the F₂ when crossed to orange, but there was some evidence that a third gene (Y ₁) was segregating in some crosses. Tinge orange-white x yellow crosses gave approximately the same results as orange x white crosses, confirming that the same Y- and Y ₂-genes were segregating.In crosses between orange lines and a light yellow line (RY) certain F₁ 's appeared to have a light orange xylem and a fairly dark orange phloem, which seems to be some evidence for the existence of recessive yellow. Although almost nothing is known yet about the genetics of RY it is assumed that it still carries a dominant inhibitor gene which may be leaky in heterozygous condition. The value of such a line as an aid in the selection of superior orange lines is discussed.Alpha- and beta-carotene were found to be the major pigments in orange carrot tissue; phytofluene, zetacarotene, gamma-carotene and xanthophylls were shown to be present in smaller amounts. Besides xanthophylls and a small amount of beta-carotene dark yellow carrot tissue appeared to contain an appreciable amount of an unidentified pigment (pigment I). Light yellow and white phloem or xylem tissue were low in total carotenoids.Research supported by the College of Agricultural and Life Sciences and by a grant from the Campbell Soup Company, Camden, New Jersey, USA. The investigation is a portion of a thesis submitted in 1978 as partial fulfillment of the requirements of the PhD degree.