多胚水稻ApⅢ（双13）的胚胎学观察

对多胚水稻（Ｏｒｙｚａ ｓａｔｉｖａ Ｌ．）ＡｐⅢ的大量成熟颖果、人工萌发的幼苗和开花后３～５ ｄ 的幼嫩颖果进行的整体解剖和显微制片观察表明：ＡｐⅢ的５０００粒成熟颖果中,８９．０％ 含单胚单苗,８．９％ 和１．２％分别含双胚双苗和三胚三苗;７００多粒幼嫩颖果中,９０．０％ ～９５．０％ 含单胚,５．０％ ～７．０％ 含双胚。因制片的数目有限,未见到含三胚的;在含单胚和多胚颖果中,胚均位于同一胚囊的珠孔端,未见到胚囊以外存在不定胚。根据上述结果,似可以认为ＡｐⅢ单粒颖果的双胚和三胚是由同一胚囊内的卵细胞和１或２个助细胞受精或不受精发育而来的     

包囊游仆虫休眠包囊的超微结构研究

包囊游仆虫休眠包囊中,各类纤毛器的纤毛基体上方的大部分纤毛杆退化,或仅保留毛基体,有时部分额腹棘毛的毛基体也瓦解消失。残留纤毛的纤毛杆周围微管和中央微管仍具有“9 2”结构特征,也有少数纤毛杆出现2套“9 2”微管共处于一层纤毛膜内的现象。毛基体中周围三联体微管的中央形成微管形结构聚合体,基体附属结构仅存在基体间连接及纤毛器托架的残余物;非纤毛区皮层表膜下未见微管层。纤毛区皮层含纤毛器腔周围微管层(相当于表膜下微管层)、纤毛器深部及附近的微管束和分散的微管群。并且,纤毛区皮层囊泡内含有呈不同形态的纤毛杆结构;大核核孔明显变大,核孔数目减少,核孔内膜附着染色质。     

复合氨基酸治疗眼角膜溃疡的研究

复合氨基酸在临床上的应用越来越被人们重视,我们利用水解猪血粉的方法得到含１７种氨基酸的复合液,配制成滴眼剂用于多种原因引起的眼角膜溃疡疾病的治疗研究取得了较好的效果。     

Reduced lignin in transgenic plants containing a caffeic acidO-methyltransferase antisense gene

Lignin is a major structural polymer of secondarily thickended plant vascular tissue and fibres, imparting mechanical strength to stems and trunks and hydrophobicity to conducting vessels. Constitutive expression of a lucerne caffeic acid 3-O-methyltransferase antisense RNA in transgenic tobacco leads to a significant reduction in lignin content, particularly in the younger parts of the stems, without apparent alterations in lignin monomer composition. These observations open up the possibility of genetically manipulating plants with reduced lignin for improved processing and biomass digestibility.     

水平回转对水稻幼苗叶细胞的影响

对在模拟微重力装置上回转１４ 天的水稻幼苗叶细胞进行了亚显微形态、电子探针和细胞酶化学研究。发现叶细胞质膜上Ｃａ２＋ －ＡＴＰ酶活性消失,膜内钙总量上升、膜外钙总量下降,细胞骨架变得疏松,细胞壁变薄并凹凸不平。叶绿体的基粒和线粒体的内嵴亦有部分变化。其变化机制,首先是细胞质膜上Ｃａ２＋ －ＡＴＰ酶活性消失,膜上钙泵停止工作,跨膜钙浓度差减小,膜内钙浓度上升,微管、微丝聚合受阻,细胞骨架疏松,分泌泡移动失去导向,从而导致细胞壁变薄等状态     

Supercritical carbon dioxide extraction of hydrocarbons from the microalgaBotryococcus braunii

Samples of the microalgaBotryococcus braunii were submitted to supercritical fluid extraction with carbon dioxide at 40 °C and pressures of 12.5, 20.0 and 30.0 MPa. The extraction yield and the fraction of the hydrocarbons in the extracts both increased with pressure and at 30 MPa these compounds were obtained rapidly. This behaviour is associated with the localization of the hydrocarbons outside the cell wall. In the extracts, which are fluid, golden and limpid, chlorophyll and phospholipids were not detected.Author for correspondence     

钆和镱对人红细胞膜脂及膜蛋白的作用

利用荧光偏振,自旋标标顺磁共振波谱和激光拉曼技术研究了钆和镱对人红细胞膜结构和功能的影响。结果表明,低浓度的Ｇｄ３＋（０．５μｍｏｌ／Ｌ）对（Ｎａ＋＋Ｋ＋）－ＡＴＰ酶和Ｍｇ２＋－ＡＴＰ酶有轻微的激活作用,而随着其浓度的增大,则明显抑制酶的活性,Ｇｄ３＋与Ｙｂ３＋和人红细胞膜作用后,降低膜脂流动性,并使膜蛋白酰胺Ｉ＇－α螺旋振动强度减弱．     

Characterization of inhibitory effects of NH2OH and its N-methyl derivatives on the O2-evolving complex of Photosystem II

Inorganic cofactors (Mn, Ca²⁺ and Cl^-) are essential for oxidation of H₂O to O₂ by Photosystem II. The Mn reductants NH₂OH and its N-methyl derivatives have been employed as probes to further examine the interactions between these species and Mn at the active site of H₂O oxidation. Results of these studies show that the size of a hydroxylamine derivative regulates its ability to inactivate O₂ evolution activity, and that this size-dependent inhibition behavior arises from the protein structure of Photosystem II. A set of anions (Cl^-, F^- and SO₄ ^2-) is able to slow NH₂OH and CH₃NHOH inactivation of intact Photosystem II membranes by exerting a stabilizing influence on the extrinsic 23 and 17 kDa polypeptides. In contrast to this non-specific anion effect, only Cl^- is capable of attenuating CH₃NHOH and (CH₃)₂NOH inhibition in salt-washed preparations lacking the 23 and 17 kDa polypeptides. However, Cl^- fails to protect against NH₂OH inhibition in salt-washed membranes. These results indicate that the attack by NH₂OH and its N-methyl derivatives on Mn occurs at different sites in the O₂-evolving complex. The small reductant NH₂OH acts at a Cl^--insensitive site whereas the inhibitions by CH₃NHOH and (CH₃)₂NOH involve a site that is Cl^- sensitive. These findings are consistent with earlier studies showing that the size of primary amines controls the Cl^- sensitivity of their binding to Mn in the O₂-evolving complex.Abbreviation MES 4-morpholinoethanesulfonic acid - PS II Photosystem II     

油菜菌核病菌生理生态研究

通过试验分析,结果得出,油菜菌核病菌生长温度范围在0～34℃之间,23℃以下菌丝生长速度与温度呈正相关,25℃以上则呈负相关,23～25℃最适宜,菌丝和菌核致死温度分别为45℃和75℃．该菌对酸碱度适应范围很广,PH1～14范围内只在PH_1条件下不能生长,其最适PH值为5～6。病菌利用铵态氮源能力最强,硝态氮源次之,不能利用亚硝态氮;对氨基酸利用能力以精氨酸最强,其次是酪氨酸、天门冬氨酸和谷氨酸,赖氨酸最差。植株内精氨酸和赖氨酸比值大的白菜型油菜“黄鳝籽”病情扩展最快。