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1.
The pericarp of the dormant sugarbeet fruit acts as a storage reservoir for nitrate, ammonium and -amino-N. These N-reserves enable an autonomous development of the seedling for 8–10 d after imbibition. The nitrate content of the seed (1% of the whole fruit) probably induces nitrate-reductase activity in the embryo enclosed in the pericarp. Nitrate that leaks out of the pericarp is reabsorbed by the emerging radicle. Seedlings germinated from seeds (pericarp was removed) without external N-supply are able to take up nitrate immediately upon exposure via a low-capacity uptake system (vmax = 0.8 mol NO
3
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·(g root FW)–1·h–1; Ks = 0.12 mM). We assume that this uptake system is induced by the seed nitrate (10 nmol/seed) during germination. Induction of a high-capacity nitrate-uptake system (vmax = 3.4 mol NO
3
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·(g root FW)–1·h–1; Ks = 0.08 mM) by externally supplied nitrate occurs after a 20-min lag and requires protein synthesis. Seedlings germinated from whole fruits absorb nitrate via a highcapacity uptake mechanism induced by the pericarp nitrate (748 nmol/pericarp) during germination. The uptake rates of the high-capacity system depend only on the actual nitrate concentration of the uptake medium and not on prior nitrate pretreatments. Nitrate deprivation results in a decline of the nitrate-uptake capacity (t1/2 of vmax = 5 d) probably caused by the decay of carrier molecules. Small differences in Ks but significant differences in vmax indicate that the low- and high-capacity nitrate-uptake systems differ only in the number of identical carrier molecules.Abbreviations NR
nitrate reductase
-
pFPA
para-fluorophenylalanine
This work was supported by a grant from Bundesministerium für Forschung und Technologie and by Kleinwanzlebener Saatzucht AG, Einbeck. 相似文献
2.
Olof Ryding 《Plant Systematics and Evolution》1995,198(1-2):101-141
Pericarp structure was investigated in 158 species of the familiesLamiaceae andVerbenaceae. Data from 221 out of 262 genera ofLamiaceae s.l. and a few ofVerbenaceae s.str. were collected in a table. A cladistic analysis was performed on the basis of pericarp characters only. The abandonment of subfam.Pogostemonoideae as a taxonomic unit is considered. Examples of groups given additional support by similarities in pericarp characters are: (1) the gynobasic-styled labiates (subfamiliesPogostemonoideae, Lamioideae, Nepetoideae); (2) aLamioideae-Pogostemonoideae-group; (3)Nepetoideae; (4) aWestringia-Hemigenia-Hemiandra-Microcorys group (in subfam.Chloranthoideae); (5) aLepechinia-Chaunostoma-group (inNepetoideae); (6) aPrunella-Cleonia-group (inNepetoideae). 相似文献
3.
Marilyn M. G. Johnstone Dennis M. Reinecke Jocelyn A. Ozga 《Journal of Plant Growth Regulation》2005,24(3):214-225
This study explores the unique growth-regulatory roles of two naturally occurring auxins, indole-3-acetic acid (IAA) and 4-chloroindole-3-acetic
acid (4-Cl-IAA), and their interactions with gibberellin (GA) during early pea (Pisum sativum L.) fruit development. We have previously shown that 4-Cl-IAA can replace the seed requirement in pea pericarp growth (length
and fresh weight), whereas IAA had no effect or was inhibitory. When applied simultaneously, gibberellin (GA3 or GA1) and 4-Cl-IAA had a synergistic effect on pericarp growth. In the present study, we found that simultaneous application of
IAA and GA3 to deseeded pericarps inhibited GA3-stimulated growth. The inhibitory effect of IAA on GA-stimulated growth was mimicked by treatment with ethephon (ethylene
releasing agent), and the inhibitory effects of IAA and ethylene on GA-mediated growth were reversed by silver thiosulfate
(STS), an ethylene action inhibitor. Although pretreatment with STS could retard senescence of IAA-treated pericarps, STS
pretreatment did not lead to IAA-induced pericarp growth. Although 4-Cl-IAA stimulated growth whereas IAA was ineffective,
both auxins induced similar levels of ethylene evolution. However, only 4-Cl-IAA-stimulated growth was insensitive to the
effects of ethylene. Gibberellin treatment did not influence the amount of ethylene released from pericarps in the presence
or absence of either auxin. We propose a growth regulatory role for 4-Cl-IAA through induction of GA biosynthesis and inhibition
of ethylene action. Additionally, ethylene (IAA-induced or IAA-independent) may inhibit GA responses under physiological conditions
that limit fruit growth. 相似文献
4.
A -amylase (EC 3.2.1.2) was identified in the outer pericarp (P) of developing seeds of wheat (Triticum aestivum L.) and compared with the well known -amylase which is synthesized during seed development in the starchy endosperm (E). The enzyme P already exists in the tissues before anthesis and vanishes at the time when E starts to accumulate. The isoelectric-focusing patterns of P and E are very similar. The relative molecular weight (Mr) of P is slightly higher than that of E (66 and 64.5 kDa, respectively). Both P and E exhibit common epitopes in addition to epitopes specific for each of them. The two enzymes were identified in small amounts in the green tissues of the developing seeds (inner pericarp and testa). No antigenic difference was detected between P and the -amylases of roots and leaves.Abbreviations
P
pericarp -amylase
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E
endosperm -amylase
- IS1
anti--amylase immune serum
- IS2
anti- and anti- amylase immune serum
- IS3
anti- amylase immune serum
- IEF
isoelectric focusing
- IgG
immunoglobulin G
The authors thank Dr. P. Ziegler (Universität Bayreuth, FRG) for stimulating discussion and for useful suggestions during the writing of the text. The authors thank Miss C. Mayer for her skillful technical assistance. 相似文献
5.
(-)-Jasmonic acid was identified as a plant growth inhibitor of the pericarp of Vicia faba by means of gas-liquid chromatography, high resolution mass spectrometry, 1H-nuclear magnetic resonance (1H-NMR), and 13C-NMR. Additionally, the pericarp contains very small amounts of abscisic acid (ABA) and 4-dihydrophaseic acid. The highest level of jasmonic acid was reached prior to full pericarp length. This amount (3 g g-1 fresh weight) is similar to the maximal ABA content in the developing seed. Jasmonic acid is a plant growth inhibitor possessing a relative activity in the wheat seedling bioassay of 1–2.5%, compared to ABA. Contrary to ABA, jasmonic acid does not cause retardation of leaf emergence. The possible physiological role of jasmonic acid in the pericarp is discussed and compared with the assumed function of ABA in developing seeds.Abbreviations ABA
abscisic acid
- DPA
4-dihydrophaseic acid
- DPAMeTMS
methyl ester trimethylsilyl ether of DPA
- EtOAc
ethyl acetate
- Et2O
ether
- MS
mass spectrometry
- NMR
nuclear magnetic resonance
- GLC
gas-liquid chromatography
- TLC
thin-layer chromatography
- UV
ultraviolet light 相似文献
6.
荔枝果皮总蛋白质提取及双向电泳体系的建立 总被引:1,自引:0,他引:1
用TCA-丙酮、丙酮和酚3种方法提取荔枝(Litchi chinensis Sonn.)果皮的总蛋白质,比较了蛋白产量、单向SDS-PAGE和双向电泳等方面的差异,并对双向电泳体系进行探索.结果表明:酚抽提法最佳,提取的总蛋白得率最高,蛋白在单向SDS-PAGE中形成条带数目最多,最清晰;经双向电泳分离用银染显色,可检... 相似文献
7.
利用光学显微镜和扫描电镜对海三棱藨草(× Bolboschoenoplectus mariqueter (Tang & F. T. Wang))及其5个近缘种的果实形状、果皮微形态特征进行观察和分析。结果显示,海三棱藨草果实形状为双凸状,表面为波形网状纹饰,外果皮为中果皮厚度的2倍,与扁秆荆三棱( Bolboschoenus planiculmis (F. Schmidt) T. V. Egorova)明显不同,而与海滨三棱草( Bolboschoenus maritimus (L.) Palla)相似。研究结果支持将海三棱藨草归入三棱草属,不支持将海三棱藨草作为扁秆荆三棱的异名,推测其可能为海滨三棱草水滨亚种( Bolboschoenus maritimus subsp. paludosus (A. Nelson) T. Koyama)的异名。 相似文献
8.
外果皮厚度和种子大小对五种栎属橡子扩散的影响 总被引:1,自引:0,他引:1
动物对种子的扩散和贮藏是一个复杂的生态学过程,常常受到种子特征的影响。有关种子特征如何影响动物对种子扩散,许多研究结果并非完全一致。我们于2009 年9 月在黑龙江东方红林场野外和围栏内释放五种栎属橡子(Quercus mongolica,Q.serrata var. brevipetiolata,Q. aliena,Q.variabilis 和Q. liaotungensis),研究种子特征对鼠类(Apodemus peninsulae, Clethrionomys rufocanus 和Tamias sibiricus)扩散和埋藏橡子的影响。野外释放结果表明:橡子大小和外果皮厚度显著影响鼠类对橡子的扩散和埋藏。鼠类偏向扩散和埋藏种皮厚的大橡子,种皮薄的小橡子则多被原地取食。种皮厚的大橡子扩散距离显著高于种皮薄的小橡子。然而,只有外果皮的厚度显著影响围栏内花鼠对橡子的扩散和埋藏,橡子大小并非主要的影响因素。种子特征影响种子扩散的效应可能在种群和群落水平上存在差异。 相似文献
9.
10.
E. Millet M. J. Pinthus 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1980,58(6):247-252
Summary Reciprocal crosses were made between semi dwarf spring wheat cultivars (Triticum aestivum L.) differing in grain weight. The weights of the F1 grains (on maternal spikes), from intact as well as from defoliated plants, and those of the F2 grains (on f1 spikes), were examined. Grain weight was controlled primarily by the genotype of the maternal tissues (pericarp, testa or other floret or spikelet organs, including the vascular system), with complete dominance of heaviness. No indications suggesting maternal inheritance were obtained. The frequency distribution of the weights of the F2 grains indicated the presence of genotypic effects exerted by the endosperm or embryo. The embryo or endosperm factors for heaviness also seemed to be dominant.This study is based on data obtained by the senior author in his Ph. D. research at The Hebrew University of Jerusalem. The research was financed in part by The Fund for the Encouragement of Research — Histadrut — The General Federation of Labor in Israel. Contribution from the Agricultural Research Organization, Bet Dagan, Israel. No. 173-E, 1980 series 相似文献