Shamay Izhar - Academia.edu (original) (raw)
Papers by Shamay Izhar
Malformin induces curvatures, stimulates root hair and lateral root formation, promotes radial ex... more Malformin induces curvatures, stimulates root hair and lateral root formation, promotes radial expansion, inhibits elongation, wet and dry weight, cell division and cell wall synthesis in roots of Zea mays , but has no effect on protein synthesis. The growth curves (elongation, wet and dry weight) of Z. mays roots treated with malformin are cubic. Processes which are involved in inhibition of elongation are considered the primary cause of root curvatures by malformin.
Mgg Molecular General Genetics, 1985
Journal of Heredity, 1976
CYTOPLASMIC MALE STERILITY (cms)* in petunia is a classical example of cytoplasmic inheritance in... more CYTOPLASMIC MALE STERILITY (cms)* in petunia is a classical example of cytoplasmic inheritance in higher plants. Two lines of evidence suggested the occurrence of variation in plasmagenes that cause male sterility in petunia. One involves the different results ...
Theor Appl Genet, 1980
Two types of cytoplasmic hybrids were obtained by protoplast fusion. These contained either one o... more Two types of cytoplasmic hybrids were obtained by protoplast fusion. These contained either one or the other original parental nucleus and heteroplasmon, a mix of plasmons inducing cytoplasmic male sterility and fertility. In subsequent generations, following selfing, stable ...
Acta Botanica Neerlandica, 1973
In previous papers we demonstrated direct transfer of cytoplasmic male sterility (cms) in Petunia... more In previous papers we demonstrated direct transfer of cytoplasmic male sterility (cms) in Petunia via protoplast fusion. We showed further that a heteroplasmic state with respect to male sterility and fertility was obtained. Once this heteroplasmic state was achieved, the ...
Plant Science Letters, 1984
Abstract A convenient procedure for the efficient plating of cells and protoplasts at low densiti... more Abstract A convenient procedure for the efficient plating of cells and protoplasts at low densities (as low as 200/ml) was developed. Feeder cells from exponentially growing Petunia suspension cell cultures are embedded in solid medium and overlaid with a ...
Plant Molecular Biology 2, 1991
Go to AGRIS search. NATO ASI series : Series A : Life sciences (1991). Cytoplasmic male sterility... more Go to AGRIS search. NATO ASI series : Series A : Life sciences (1991). Cytoplasmic male sterility in petunia. ...
Plant Science Letters, 1984
Abstract The growth hormones 6-benzylaminopurine (BAP), naphthaleneacetic acid (NAA) and 2, 4-dic... more Abstract The growth hormones 6-benzylaminopurine (BAP), naphthaleneacetic acid (NAA) and 2, 4-dichlorophenoxy-acetic acid (2, 4-D) were used as a selection tool in some protoplast fusion experiments involving different inbred lines of Petunia. The efficiency of ...
Theoretical and Applied Genetics, 1971
In the locules of fertile Petunia hybrida anthers the in vivo pH during meiosis is 6.8--7.0 and n... more In the locules of fertile Petunia hybrida anthers the in vivo pH during meiosis is 6.8--7.0 and no callase activity can be detected. Towards the end of the tetrad stage, the pH drops to 5.9--6.2 followed by a burst of callase activity. Subsequently, callose in the tetrad walls is digested and the quartets of microspores are released into the anther locules and develop into pollen grains. In the anther locules of one cytoplasmic male sterile (cms) Petunia type the pH drop and strong callase activity are already evident at early meiotic stages. Consequently, the callose already accumulated in the pollen mother cell (PMC) walls is digested and the PMC's cease to develop and are degraded. In another sterile genotype, the pH of the locule remains high (6.8--7.0), no callase activity is detected at the end of tetrad stage and the callose walls remain intact until a very late stage. It is suggested that the timing of callase activity is critical for the normal development of tile male gametophyte and that faulty timing may result in male sterility. Measurements of pH in vivo and assays for callase activity in vitro indicate that the low pH is a precondition for the enzyme activity. Furthermore, it is suggested that the activation of callase in vivo is in some way connected with the changes in the pH of the locule.
Theoretical and Applied Genetics, 1984
This paper describes the relationship between the restorer gene and the gene for male sterility i... more This paper describes the relationship between the restorer gene and the gene for male sterility in the background of normal cytoplasm. We combined these two traits by crosses in one plant, thus making genetic analysis possible. Two main conclusions can be drawn: 1. The restorer gene and the gene for male sterility are located at different loci which segregate independently one from the other. 2. The Rf allele does not affect the expression of the e allele.
Plant Molecular Biology, 1985
We have characterized two related regions of two Petunia mitochondrial genomes in order to unders... more We have characterized two related regions of two Petunia mitochondrial genomes in order to understand how plant mt genomes from a cytoplasmic male sterile (cms) line and a fertile line diverge from one another. Restriction maps of these regions indicate that a sequence arrangement shared by the two genomes adjoins sequences which are not shared at the co~responding locations in the two genomes. A point where the mt genomes from the cms line and the fertile lines diverge from each other was identified and mapped.
Plant Molecular Biology, 1988
The progeny of somatic hybrid Petunia plants derived from the fusion of a male-fertile line and a... more The progeny of somatic hybrid Petunia plants derived from the fusion of a male-fertile line and a cytoplasmic male-sterile (cms) line were examined. Male-fertile progeny derived from three different male-sterile somatic hybrid plants did not exhibit the mitochondrial DNA (mtDNA) arrangement which has previously been correlated with cms in Petunia. The cms-associated mtDNA arrangement was present in the male-sterile predecessors of these fertile revertants. Thus, it is concluded that the loss of this mtDNA arrangement is associated with reversion to fertility in the progeny of the unstable somatic hybrid petunia plants.
Plant Cell Reports, 1984
Eggplant (Solanum melongena L.) mesophyll protoplasts were obtained from in vitro growing plants ... more Eggplant (Solanum melongena L.) mesophyll protoplasts were obtained from in vitro growing plants of line 410 and cv. 'Classic'. Relatively high (15%) plating efficiency was achieved using petri dishes with alternate quadrants containing reservoir medium (R medium + 1% activated charcoal) and culture medium. Shoot regeneration occurred within 6 weeks following initiation of protoplast culture.
Plant Cell Reports, 1984
Significantly higher than normal mitotic index (MI) values were induced in Petunia cell suspensio... more Significantly higher than normal mitotic index (MI) values were induced in Petunia cell suspensions following treatments with colchicine, aphidicolin, drastic medium replacement, or a sequential application of aphidicolin and colchicine. This last treatment yielded the highest MI values: cells incubated with 30 μg/ml aphidicolin for 18 h, then cultured in drug-free medium for 8 h and finally exposed to 0.1% colchicine for 8 additional hours exhibited MI of 62.8% and 65.7% respectively, for the two cell lines in study.
MGG Molecular & General Genetics, 1985
The chloroplast genomes of three sets of Petunia somatic hybrids were analyzed to examine the rel... more The chloroplast genomes of three sets of Petunia somatic hybrids were analyzed to examine the relationship between chloroplast DNA (cpDNA) composition and cytoplasmic male sterility (CMS). Chloroplast genomes of somatic hybrid plants were identified either by restriction and electrophoresis of purified cpDNAs or by hybridization of total DNA digests with cloned cpDNA probes that distinguish the parental genomes.
MGG Molecular & General Genetics, 1995
In petunia, a mitochondrial (mt) locus, S-Pcf, has been found to be strongly associated with cyto... more In petunia, a mitochondrial (mt) locus, S-Pcf, has been found to be strongly associated with cytoplasmic male sterility (CMS). The S-Pcf locus consists of three open reading frames (ORF) that are co-transcribed. The first ORF, Pcf, contains parts of the atp9 and coxlI genes and an unidentified reading frame, urf-s. The second and third ORFs contain NADH dehydrogenase subunit 3 (had3) and ribosomal protein S12 (rpsl2) sequences, respectively. The had3 and rpsl2 sequences included in the S-Pcf locus are identical to the corresponding sequences on the mt genome of fertile petunia. In both CMS and fertile petunia, only a single copy of nad3 and rpsl2 has been detected on the physical map of the main mt genome. The origin of the urf-s sequence and the molecular events leading to the formation of the chimeric S-Pcf locus are not known. This paper presents evidence indicating that two different mt sequences, related to urf-s and found in fertile petunia lines (orf-h and Rf-1), might have been involved in the molecular evolution of the S-Pcflocus.
MGG Molecular & General Genetics, 1983
In previous papers we demonstrated direct transfer of cytoplasmic male sterility (cms) in Petunia... more In previous papers we demonstrated direct transfer of cytoplasmic male sterility (cms) in Petunia via protoplast fusion. We showed further that a heteroplasmic state with respect to male sterility and fertility was obtained. Once this heteroplasmic state was achieved, the ...
Malformin induces curvatures, stimulates root hair and lateral root formation, promotes radial ex... more Malformin induces curvatures, stimulates root hair and lateral root formation, promotes radial expansion, inhibits elongation, wet and dry weight, cell division and cell wall synthesis in roots of Zea mays , but has no effect on protein synthesis. The growth curves (elongation, wet and dry weight) of Z. mays roots treated with malformin are cubic. Processes which are involved in inhibition of elongation are considered the primary cause of root curvatures by malformin.
Mgg Molecular General Genetics, 1985
Journal of Heredity, 1976
CYTOPLASMIC MALE STERILITY (cms)* in petunia is a classical example of cytoplasmic inheritance in... more CYTOPLASMIC MALE STERILITY (cms)* in petunia is a classical example of cytoplasmic inheritance in higher plants. Two lines of evidence suggested the occurrence of variation in plasmagenes that cause male sterility in petunia. One involves the different results ...
Theor Appl Genet, 1980
Two types of cytoplasmic hybrids were obtained by protoplast fusion. These contained either one o... more Two types of cytoplasmic hybrids were obtained by protoplast fusion. These contained either one or the other original parental nucleus and heteroplasmon, a mix of plasmons inducing cytoplasmic male sterility and fertility. In subsequent generations, following selfing, stable ...
Acta Botanica Neerlandica, 1973
In previous papers we demonstrated direct transfer of cytoplasmic male sterility (cms) in Petunia... more In previous papers we demonstrated direct transfer of cytoplasmic male sterility (cms) in Petunia via protoplast fusion. We showed further that a heteroplasmic state with respect to male sterility and fertility was obtained. Once this heteroplasmic state was achieved, the ...
Plant Science Letters, 1984
Abstract A convenient procedure for the efficient plating of cells and protoplasts at low densiti... more Abstract A convenient procedure for the efficient plating of cells and protoplasts at low densities (as low as 200/ml) was developed. Feeder cells from exponentially growing Petunia suspension cell cultures are embedded in solid medium and overlaid with a ...
Plant Molecular Biology 2, 1991
Go to AGRIS search. NATO ASI series : Series A : Life sciences (1991). Cytoplasmic male sterility... more Go to AGRIS search. NATO ASI series : Series A : Life sciences (1991). Cytoplasmic male sterility in petunia. ...
Plant Science Letters, 1984
Abstract The growth hormones 6-benzylaminopurine (BAP), naphthaleneacetic acid (NAA) and 2, 4-dic... more Abstract The growth hormones 6-benzylaminopurine (BAP), naphthaleneacetic acid (NAA) and 2, 4-dichlorophenoxy-acetic acid (2, 4-D) were used as a selection tool in some protoplast fusion experiments involving different inbred lines of Petunia. The efficiency of ...
Theoretical and Applied Genetics, 1971
In the locules of fertile Petunia hybrida anthers the in vivo pH during meiosis is 6.8--7.0 and n... more In the locules of fertile Petunia hybrida anthers the in vivo pH during meiosis is 6.8--7.0 and no callase activity can be detected. Towards the end of the tetrad stage, the pH drops to 5.9--6.2 followed by a burst of callase activity. Subsequently, callose in the tetrad walls is digested and the quartets of microspores are released into the anther locules and develop into pollen grains. In the anther locules of one cytoplasmic male sterile (cms) Petunia type the pH drop and strong callase activity are already evident at early meiotic stages. Consequently, the callose already accumulated in the pollen mother cell (PMC) walls is digested and the PMC's cease to develop and are degraded. In another sterile genotype, the pH of the locule remains high (6.8--7.0), no callase activity is detected at the end of tetrad stage and the callose walls remain intact until a very late stage. It is suggested that the timing of callase activity is critical for the normal development of tile male gametophyte and that faulty timing may result in male sterility. Measurements of pH in vivo and assays for callase activity in vitro indicate that the low pH is a precondition for the enzyme activity. Furthermore, it is suggested that the activation of callase in vivo is in some way connected with the changes in the pH of the locule.
Theoretical and Applied Genetics, 1984
This paper describes the relationship between the restorer gene and the gene for male sterility i... more This paper describes the relationship between the restorer gene and the gene for male sterility in the background of normal cytoplasm. We combined these two traits by crosses in one plant, thus making genetic analysis possible. Two main conclusions can be drawn: 1. The restorer gene and the gene for male sterility are located at different loci which segregate independently one from the other. 2. The Rf allele does not affect the expression of the e allele.
Plant Molecular Biology, 1985
We have characterized two related regions of two Petunia mitochondrial genomes in order to unders... more We have characterized two related regions of two Petunia mitochondrial genomes in order to understand how plant mt genomes from a cytoplasmic male sterile (cms) line and a fertile line diverge from one another. Restriction maps of these regions indicate that a sequence arrangement shared by the two genomes adjoins sequences which are not shared at the co~responding locations in the two genomes. A point where the mt genomes from the cms line and the fertile lines diverge from each other was identified and mapped.
Plant Molecular Biology, 1988
The progeny of somatic hybrid Petunia plants derived from the fusion of a male-fertile line and a... more The progeny of somatic hybrid Petunia plants derived from the fusion of a male-fertile line and a cytoplasmic male-sterile (cms) line were examined. Male-fertile progeny derived from three different male-sterile somatic hybrid plants did not exhibit the mitochondrial DNA (mtDNA) arrangement which has previously been correlated with cms in Petunia. The cms-associated mtDNA arrangement was present in the male-sterile predecessors of these fertile revertants. Thus, it is concluded that the loss of this mtDNA arrangement is associated with reversion to fertility in the progeny of the unstable somatic hybrid petunia plants.
Plant Cell Reports, 1984
Eggplant (Solanum melongena L.) mesophyll protoplasts were obtained from in vitro growing plants ... more Eggplant (Solanum melongena L.) mesophyll protoplasts were obtained from in vitro growing plants of line 410 and cv. 'Classic'. Relatively high (15%) plating efficiency was achieved using petri dishes with alternate quadrants containing reservoir medium (R medium + 1% activated charcoal) and culture medium. Shoot regeneration occurred within 6 weeks following initiation of protoplast culture.
Plant Cell Reports, 1984
Significantly higher than normal mitotic index (MI) values were induced in Petunia cell suspensio... more Significantly higher than normal mitotic index (MI) values were induced in Petunia cell suspensions following treatments with colchicine, aphidicolin, drastic medium replacement, or a sequential application of aphidicolin and colchicine. This last treatment yielded the highest MI values: cells incubated with 30 μg/ml aphidicolin for 18 h, then cultured in drug-free medium for 8 h and finally exposed to 0.1% colchicine for 8 additional hours exhibited MI of 62.8% and 65.7% respectively, for the two cell lines in study.
MGG Molecular & General Genetics, 1985
The chloroplast genomes of three sets of Petunia somatic hybrids were analyzed to examine the rel... more The chloroplast genomes of three sets of Petunia somatic hybrids were analyzed to examine the relationship between chloroplast DNA (cpDNA) composition and cytoplasmic male sterility (CMS). Chloroplast genomes of somatic hybrid plants were identified either by restriction and electrophoresis of purified cpDNAs or by hybridization of total DNA digests with cloned cpDNA probes that distinguish the parental genomes.
MGG Molecular & General Genetics, 1995
In petunia, a mitochondrial (mt) locus, S-Pcf, has been found to be strongly associated with cyto... more In petunia, a mitochondrial (mt) locus, S-Pcf, has been found to be strongly associated with cytoplasmic male sterility (CMS). The S-Pcf locus consists of three open reading frames (ORF) that are co-transcribed. The first ORF, Pcf, contains parts of the atp9 and coxlI genes and an unidentified reading frame, urf-s. The second and third ORFs contain NADH dehydrogenase subunit 3 (had3) and ribosomal protein S12 (rpsl2) sequences, respectively. The had3 and rpsl2 sequences included in the S-Pcf locus are identical to the corresponding sequences on the mt genome of fertile petunia. In both CMS and fertile petunia, only a single copy of nad3 and rpsl2 has been detected on the physical map of the main mt genome. The origin of the urf-s sequence and the molecular events leading to the formation of the chimeric S-Pcf locus are not known. This paper presents evidence indicating that two different mt sequences, related to urf-s and found in fertile petunia lines (orf-h and Rf-1), might have been involved in the molecular evolution of the S-Pcflocus.
MGG Molecular & General Genetics, 1983
In previous papers we demonstrated direct transfer of cytoplasmic male sterility (cms) in Petunia... more In previous papers we demonstrated direct transfer of cytoplasmic male sterility (cms) in Petunia via protoplast fusion. We showed further that a heteroplasmic state with respect to male sterility and fertility was obtained. Once this heteroplasmic state was achieved, the ...