Rye Embryos Research Articles

Germination of Rye Embryos Following Hydration-Dehydration Treatments: Enhancement of Protein and RNA Synthesis and Earlier Induction of DNA Replication

On germination of low viability embryos of rye, var. Lovasz Patonai, the rate of protein syn thesis increases during the early hours of imbibition and high rates of DNA replication commence around the 9th hour. If embryos are imbibed for 3 or 6 h then dehydrated back to their original weight, their rate of protein synthesis when next imbibed closely corresponds to that of embryos germinated for a period equal to that of the hydration pre-treatment plus the duration of the second imbibition. Pre-treatment also enhances subsequent RNA synthesis and embryos hydrated for 9 h then dehydrated start major DNA synthesis at once as water is again supplied. Many changes occurring during these periods of hydration pre treatment must therefore be stable to subsequent dehydration. Damage occurs to areas that are first active in protein and RNA synthesis if pre-treatments extend beyond 9 h and sub sequent germination of the embryo is then impaired. The implications of these results are discussed in relation to the effects of hydration pre-treatments upon enhanced germination and the stability to dehydration of the products of early RNA and protein synthesis.

Protein synthesis and loss of viability in rye embryos. The lability of transferase enzymes during senscence.

Poor germination and eventual loss of viability of rye grains on storage reflects a decreasing ability of embryos to synthesize protein in vivo. Cell-free protein-synthesizing systems from low viability embryo stocks exhibit lesions in the soluble components of the post-ribosomal supernatant fractions. tRNA and aminoacyl-tRNA synthetases are not impaired. The activity of enzymes concerned with transfer of phenylalanyl-tRNA from the aminoacyl to the peptidyl site on the ribosome is slightly decreased. The transfer enzymes (transferase I) involved in the binding of phenylalanyl-tRNA to the aminoacyl site show a loss of activity that closely reflects the loss of viability and the decline of protein synthesis of the embryo in vivo. The inactivation of labile transferase I components may be a major factor leading to senescence and loss of viability in rye grains.

Tobacco mosaic virus RNA directs the synthesis of a coat protein peptide in a cell-free system from wheat

Tobacco mosaic virus (TMV) RNA stimulates amino acid incorporation into protein in cell-free extracts from wheat germ, rye embryo and Escherichia coli. The properties of the wheat germ system are examined and the nature of the viral RNA-induced products studied with the aid of a virus mutant carrying a threonine → methionine replacement in its coat protein. A peptide containing this methionine residue is present in tryptic digests of mutant RNA-directed cell-free products, and is absent from digests of wild type RNA-directed products. The undigested cell-free product contains a very large number of polypeptides with molecular weights from 10,000 to 140,000, but little or no synthesis of correct sized coat protein is observed.

Protein synthesis and the viability of rye grains. Loss of activity of protein-synthesizing systems in vitro associated with a loss of viability.

A study was made of the integrity of some components of the protein-synthesizing system from viable and non-viable embryos of rye grains. In comparison with viable-embryo components both post-ribosomal supernatant and ribosomal fractions from non-viable embryos are impaired, for neither will fully support polyphenylalanine synthesis in poly(U)-directed cell-free systems. The lesion in the supernatant lies in components other than the tRNA or the aminoacyl-tRNA synthetase, for these are as functional as those present in the fully active cell-free systems from viable embryos. The ribosomes of embryos of lowered viability show considerable fragmentation and degradation of both 18S and 25S rRNA. This breakdown does not, however, account for the complete lack of polypeptide synthesis in the poly(U)-directed non-viable-embryo system, for if provided with viable-embryo supernatant, non-viable-embryo ribosomes will sustain 60% of the viable-embryo ribosome activity. A lesion in non-viable-embryo supernatant has been located in the binding of the aminoacyl-tRNA to the ribosome. The impaired components in both supernatant and ribosomes in systems in vitro may reflect the site of faults in protein synthesis in vivo in the early hours of germination. The development of these lesions during grain storage could contribute to senescence and loss of viability in the embryos of rye.

Embryogenesis and germination in rye (Secale cereale L.)

When rye embryos imbibe water they rapidly return to a condition of biochemical and structural complexity. Three stages of imbibition can be recognised: Phase I a short period (10 min) of physical wetting; Phase II a longer period (1 h) when little further imbibition occurs, followed by Phase III a continuous phase of active water uptake. The latter coincides with an increase in respiration rate and an increase both in the number of mitochondria and of cristae within them. Changes in fine structure become evident in all organelles in Phase III, after 2 h of imbibition. In the unimbibed embryo endoplasmic reticulum is present only as short crescents associated with electron lucent bodies, but in Phase III the endoplasmic reticulum proliferates to form many surrounding cirlets. After 6 h these circlets become fewer and instead the endoplasmic reticulum is seen in close association with the nuclear membrane. Concurrently incorporation of radioactive uridine and thymidine is first detectible. This suggests that the large increase in protein synthesis occurs on new ribosomes present on the reticulum associated with the nuclear membrane. For the first 6 h protein synthesis must occur either on polysomes within the dense packing of ribosomes or on these circlets of endoplasmic reticulum associated with electron lucent bodies.

Accumulation of a Distinct Macromolecular Component in Rye Embryos as a Result of Vernalization

MANY attempts have been made to relate the phenomena of vernalization to chemical entities, particularly macromolecular components, such as nucleic acids1, proteins2, and related substances3. The results so far obtained have been either negative or inconclusive. The present communication reports a successful demonstration of the accumulation of an electrophoretically homogeneous macromolecular component in the vernalized embryos (and seedlings) of Petkus winter rye (supplied by F. von Lochow, Petkus Co., Bergen, Germany). This component was greatly reduced by devernalization and was absent from non-vernalized embryos.

Production of lysergic acid derivatives by a strain of Claviceps paspali Stevens and Hall in submerged culture.

A STRAIN of Claviceps paspali Stevens and Hall isolated from the grass Paspalum distichum L. found growing on a hill in the neighbourhood of Rome was found, after propagation on a rye embryo grown on agar1, to be capable of producing lysergic acid derivatives in submerged culture.

OBSERVATIONS ON CEREAL EMBRYOS IN RELATION TO THE "EMBRYO TEST" FOR LOOSE SMUTS

The embryos of wheat, barley, oats, and rye may be distinguished readily by differences in the shape of the scutella and by the relative sizes of the root initials. Photomicrographs of transverse sections of a wheat embryo show that the embryonic leaves within the coleoptile are arranged alternately, the first one facing towards the scutellum. Their edges are curled around the growing point and meet on the opposite side of the cavity in the coleoptile. A structure, referred to as a "pad", covers the side of the embryo facing the endosperm.Abnormalities found in whole barley embryos include the dormant mycelium of loose smut which appears as brown threads mainly in the surface tissues of the scutellum. Frost, occurring during the later development of the kernel, causes a stunting of the embryo, particularly of the coleoptile, and the production of small particles of yellowish-brown pigment in the tissues of the embryo. Other abnormalities are figured and discussed.

The Germination of Ergot Conidia as Affected by Host Plant, and the Culture of Ergot on Excised Roots and Embryos of Rye

Physiologia PlantarumVolume 9, Issue 3 p. 350-355 The Germination of Ergot Conidia as Affected by Host Plant, and the Culture of Ergot on Excised Roots and Embryos of Rye A. St. Garay, A. St. Garay Research Institute for Medicinal Plants, Budapest XII, Dániel ut 40Search for more papers by this author A. St. Garay, A. St. Garay Research Institute for Medicinal Plants, Budapest XII, Dániel ut 40Search for more papers by this author First published: July 1956 https://doi.org/10.1111/j.1399-3054.1956.tb07796.xCitations: 9AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume9, Issue3July 1956Pages 350-355 RelatedInformation

Nucleic Acid Content of Petkus Rye Embryos in Relation to Vernalization and Devernalization

Pot,jms winter rye hus been subjectcd to vernalization treatmullts using the techniquo orrostricted moisture content in plastic boxoB lillod with filter paper. Grain so troated has also he en subjeeted to the dovol'l1aJizing action of temperat1ll'es highOl' than those aL which vernalization proceods

Accelerating Effect of an Extract of Vernalized Embryos of Winter Rye on Flower Initiation in Unvernalized Embryos

Accelerating Effect of an Extract of Vernalized Embryos of Winter Rye on Flower Initiation in Unvernalized Embryos

Vernalization of Excised Mustard Embryo

IN contrast to vernalized wheat and rye, vernalized unsplit mustard seed does not become devernalized under high temperature1. Experiments were undertaken with mustard T.102 to find out whether (i) embryos excised from dried vernalized unsplit seeds would produce vernalized plants ; and (ii) whether the effects of chilling excised embryos of mustard in different media would be similar to those observed by Gregory and Purvis2 and Purvis3 with embryos of winter rye.

Studies in Vernalisation of Cereals: VII. A Study of the Conditions of Formation and the Subsequent Growth of Dwarf Embryos of Rye

Journal Article Studies in Vernalisation of Cereals: VII. A Study of the Conditions of Formation and the Subsequent Growth of Dwarf Embryos of Rye Get access P. S. NUTMAN P. S. NUTMAN Research Institute of Plant Physiology, Imperial College of Science and TechnologyLondon Search for other works by this author on: Oxford Academic PubMed Google Scholar Annals of Botany, Volume 5, Issue 2, April 1941, Pages 353–374, https://doi.org/10.1093/oxfordjournals.aob.a087398 Published: 01 April 1941

Vernalization of Fragments of Embryo Tissue

EMBRYOS of cereal grains, separated from the endosperm and cultured on a medium containing sugar, can be vernalized by exposure to a temperature of 1° C. in the same way as whole grains1,2,3,4. In order to locate more precisely the tissues concerned in the process, embryos of Petkus winter rye were mutilated in various ways before vernalization treatment. In this preliminary experiment only two embryos were subjected to each type of mutilation.

Vernalization of Excised Embryos

IN a previous letter1 attention was directed to the fact that the process of vernalization could be carried out successfully on excised embryos of winter rye, var. Petkus (fuller information has been published elsewhere2). The embryos in the case referred to were removed from grains previously soaked for 5 hr. in a sterilizing solution and were kept on an agar medium containing nutrient salts and glucose.