In cotyledons of 6-day-old amaranth seedlings, the large subunit (LSU) and the small subunit (SSU) polypeptides of ribulose-1,5-bisphosphate carboxylase are not synthesized in the absence of light. When dark-grown seedlings were transferred into light, synthesis of both polypeptides was induced within the first 3 to 5 hr of illumination without any significant changes in levels of their mRNAs. ...

We have shown that amide-linked IAA (indole-3-acetic acid) conjugates accumulated to high levels during maturation of bean seeds (K. Bialek and J.D. Cohen [1989] Plant Physiol 91: 775-779). In the present study, we were interested in the fate of these and other IAA conjugates during seed germination. The content of amide-linked conjugates of IAA in cotyledons declined dramatically during the fi...

Fluorescent products of lipid peroxidation accumulate with age in microsomal membranes from senescing cotyledons of Phaseolus vulgaris. The temporal pattern of accumulation is closely correlated with a rise in the lipid phase transition temperature reflecting the formation of gel phase lipid. Increased levels of fluorescent peroxidation products are also detectable in total lipid extracts of se...

The mechanism of cytokinin-induced cell expansion in cotyledons excised from dark-grown seedlings of radish (Raphanus sativus L.) and cucumber (Cucumus sativus L.) was studied. Cotyledons were incubated in dim light with or without 17 micromolar zeatin for periods up to 3 days. Fresh weights and osmotic potentials were measured daily. Cell wall extensibility properties were measured before and ...

Storage protein hydrolysis in the cotyledons of germinating mung beans (Phaseolus aureus Roxb.) was examined by histochemical techniques, and the autolytic capacity of isolated protein bodies was studied with biochemical methods. The localization of endopeptidase activity within the cotyledons was studied using an India ink-gelatin film technique. After 24 hours of imbibition, a low level of en...

Suimmary. Nucleotide compositions of soluble (sRNA), whole-cell, and in one instance particulate and nonparticulate, RNA of embryos, cotyledons (dark and lightgrown), leaves, stems, ancd roots of Gossypium hirsuttum were compared. Evidence of substantial differences in the overall compositions of the RNAs was not obtained. However, a tendency for some plant parts to differ, particularly in sRNA...

Herbicidal Action of Monuron, Light, Oxygen, Singlet Oxygen, Plant Pigments Monuron treatment of detached flax cotyledons caused a rapid inhibition of C 02 fixation in darkness and light. Chlorophyll breakdown was promoted by increased light intensity. Ethane generation, an indicator of membrane damage, increased as the chlorophyll level decreased. The carotene pigments were destroyed more rapi...

Intermediary forms of microbodies, glyoxyperoxisomes, are most likely synthesized at the stage of replacement of glyoxysomes by peroxisomes during the greening of fatstoring cells of cucumber cotyledons. This hypothesis is supported by three lines of results: 1. The levels of both glycollate oxidase and malate synthase are increased in the microbody fractions upon illumination of cotyledons. 2....

Phosphoinositides play important roles in plant growth and development. Several SAC domain phosphoinositide phosphatases have been reported to be for Here, we show functional analysis of SUPPRESSOR OF ACTIN 6 (SAC6) SAC8 Arabidopsis, a subfamily containing SAC-domain two transmembrane motifs. We isolated an Arabidopsis mutant ncp2 that lacked cotyledons seedling embryo pid, background defective...

Malate synthase is synthesized de novo in the very phase of germination. Its molecular and immunological properties do not differ from those of malate synthase from fully developed cotyledons. Radioactive leucine was administered to dry seeds of cucumber, and its incorporation into proteins of cotyledons was examined after 2 days of germination. The specific radioactivity of malate synthase, pu...