Lipid content has been determined for two types of lipid-rich vesicles isolated from bush bean cotyledon at 24 hr of germination. The larger, nonassociating vesicles are four to six times richer in triglyceride than the smaller vesicles which associate strongly among themselves, as well as with smooth membranes in the cell. The larger vesicles contain about 640 micromoles of phospholipid per gr...

We analyzed the natural genetic variation between Landsburg erecta (Ler) and Cape Verde Islands (Cvi) accessions by studying 105 recombinant inbred lines to search for players in the regulation of sensitivity to light signals perceived by phytochromes in etiolated seedlings of Arabidopsis. In seedlings grown under hourly pulses of far-red (FR) light, we identified three quantitative trait loci ...

The transport of salicylic acid (SA) was studied in cucumber (Cucumis sativus L.) using 14C-labeled benzoic acid that was injected in the cotyledons at the time of inoculation. Primary inoculation with tobacco necrosis virus (TNV) on the cotyledons led to an induction of systemic resistance of the first primary leaf above the cotyledon against Colletotrichum lagenarium as early as 3 d after ino...

Plant seedlings have either one or two cotyledons. The mechanisms that regulate this organ number are poorly understood. Mutations in the RECEPTOR-LIKE PROTEIN KINASE1 (RPK1) gene of the dicot Arabidopsis have only one cotyledon, with low penetrance due to complex genetic redundancy. An analysis of patterning genes required for cotyledon initiation showed that these have normal expression patte...

Although resprouting plays an important role in facilitating persistence of damaged seedlings, the functional attributes of cotyledons and taproots during resprouting of 1-year oak seedlings are not well explored. In this study, cotyledons were removed from Quercus mongolica seedlings to explore resprouting in response to simulated disturbance as a function of shoot clipping, and to examine the...

Tylosema esculentum (marama) beans and tubers are used as food, and traditional medicine against diarrhoea in Southern Africa. Rotaviruses (RVs) are a major cause of diarrhoea among infants, young children, immunocompromised people, and domesticated animals. Our work is first to determine anti-RV activity of marama bean and tuber ethanol and water extracts; in this case on intestinal enterocyte...

The interaction between simulated cotyledon herbivory and interspecific competition was studied in a greenhouse experiment using two species of trees, Acer rubrum and Quercus palustris, which commonly invade abandoned agricultural fields. Herbivory treatments were applied as a gradient of cotyledon removal for A. rubrum with 0, 25, 50, 75, and 100% of cotyledon tissue removed. Cotyledons from Q...

Cotyledon expansion in response to blue light was compared for wild-type Arabidopsis thaliana (L.) Heynh. and the mutants blu3 and hy4, which show reduced inhibition of hypocotyl growth in blue light. White, blue, and red light stimulated cotyledon expansion in both intact and excised cotyledons of wild-type seedlings (ecotypes No-0, WS, Co-0, La-er). Cotyledons on intact blu3 and hy4 seedlings...

Seed dormancy is a key adaptive trait in plants responsible for the soil seed bank. The long established hormone-balance theory describes the antagonistic roles of the dormancy promoting plant hormone abscisic acid (ABA), and the germination promoting hormone gibberellin (GA) in dormancy control. Light, temperature, and other dormancy-breaking signals function to modulate the synthesis and perc...