Germination and seedling development are crucial phases in a plant’s life cycle with economical agronomical implications. The RNA quality seeds is linked to seed viability, being an important agronomic trait since this leads loss germination efficiency. In addition, can be phosphorous reservoir seeds, affecting the efficiency of mobilisation nutrients towards seedlings. However, knowledge about...

Protein storage vacuoles were examined for the induction of H+-pyrophosphatase (H+-PPase), H+-ATPase, and a membrane integral protein of 23 kD after seed germination. Membranes of protein storage vacuoles were prepared from dry seeds and etiolated cotyledons of pumpkin (Cucurbita sp.). Membrane vesicles from etiolated cotyledons had ATP- and pyrophosphate-dependent H+-transport activities. H+-A...

Phytoalexin biosynthesis is part of the defense mechanism of soybean (Glycine max) plants against attack by the fungus Diaporthe phaseolorum f. sp. meridionalis (Dpm), the causal agent of stem canker disease. The treatment of soybean cotyledons with Dpm elicitor or with sodium nitroprusside (SNP), a nitric oxide (NO) donor, resulted in a high accumulation of phytoalexins. This response did not ...

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...

During sucrose uptake by the cotyledons of castor bean seedlings excised from their endosperms, small amounts of glucose and fructose accumulate in the medium. When these hexoses were supplied separately, it was found that the rate of fructose uptake exceeded that of glucose at concentrations up to 0.5 m. Sucrose uptake exceeded that of both hexoses combined, particularly at concentrations grea...

Growth parameters and total pigment content (chlorophyll a+b and carotenoids) were investigated through postgermination, greening, natural senescence and subsequent rejuvenation of intact cotyledons of Cucurbita pepo L. (zucchini). Dark-induced senescence and recovery of the cotyledons after 2-day darkening of a whole plant were also studied. Results showed significant increase in the fresh wei...

l-Canavanine, the guanidinooxy structural analog of l-arginine, is an important nonprotein amino acid of many leguminous plants with nitrogen storage a major proported role. l-[Guanidinooxy-(14)C]canavanine, [(14)C] urea, and [(15)N]urea were injected separately into the fleshy, green cotyledons of 9-day old jack bean plants, Canavalia ensiformis (L.) DC. [Leguminosae]. There was significant tr...

The metabolism of allantoin by immature cotyledons of soybean (Glycine max L. cv Elf) grown in culture was investigated using solid state (13)C and (15)N nuclear magnetic resonance. All of the nitrogens of allantoin were incorporated into protein in a manner similar to that of each other and to the amide nitrogen of glutamine. The C-2 of allantoin was not incorporated into cellular material; pr...

We have identified transcripts of two lipoxygenase (LOXs) from 3-day-germinated etiolated cotyledons. One encodes a soluble and the other encodes a plastid LOX. They are 2520 bp and 2676 bp in size, respectively. Antibodies raised against the C-terminal 500 amino acids of the plastid LOX recognize a 90 kDa LOX in 5-day-old etiolated and green cotyledons. In mature leaves a LOX of 95 kDa is dete...

Explanted cotyledons from cineraria ‘Jester Pink’ seeds were cultured in vitro on a modified Murashige–Skoog medium containing (in M): 13.5 NAA, 13.5 2,4-D, 4.4 BAP, 13.5 NAA + 4.4 BAP, 13.5 2,4-D + 4.4 BAP or no plant growth regulators (control). Photographs were taken at 7-day intervals for 35 days to follow the embryogenic/organogenic development of the explanted cotyledons. Calorespirometri...