scholarly journals Heterochronic effects of glossy15 mutations on epidermal cell identity in maize

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1971-1981 ◽  
Author(s):  
M.M. Evans ◽  
H.J. Passas ◽  
R.S. Poethig
Keyword(s):  
Epidermal Cell ◽  
Reproductive Traits ◽  
Reproductive Development ◽  
Wild Type ◽  
Normal Position ◽  
Vegetative Development ◽  
Biochemical Traits ◽  
Juvenile Phase ◽  
Recessive Mutations ◽  
Adult Phase

Vegetative development in maize is divided into a juvenile phase and an adult phase that differ in the expression of a large number of morphological, anatomical, and biochemical traits. Recessive mutations of Glossy15 cause a premature switch in the expression of some of these phase-specific traits. Mutant plants cease producing juvenile traits (e.g. epicuticular wax) and begin to produce adult traits (e.g. epidermal hairs) significantly earlier than their wild-type siblings. In glossy15-1 plants this switch generally occurs at leaf 2 or 3 rather than at the normal position of leaf 6 or 7. An analysis of the effect of glossy15 mutations on a variety of vegetative and reproductive traits revealed that these mutations only affect the character of the epidermis. They have no effect on the overall vegetative morphology of the plant, or on its reproductive development. This phenotype is the opposite of that of the gain-of-function mutations Teopod1, Teopod2 and Teopod3, all of which prolong the expression of a large number of juvenile traits. Double mutants between glossy15 and Teopod1 or Teopod2 indicate that Glossy15 is required for the effect of Teopod1 and Teopod2 on epidermal traits but not for other aspects of the Teopod phenotype. We conclude that Glossy15 initiates or maintains the expression of juvenile epidermal traits and suppresses the expression of adult epidermal traits, and that it acts downstream of the Teopod genes.

A rice heterochronic mutant, mori1, is defective in the juvenile-adult phase change

Development ◽  
2002 ◽  
Vol 129 (1) ◽  
pp. 265-273 ◽  
Author(s):  
Kazumi Asai ◽  
Namiko Satoh ◽  
Haruto Sasaki ◽  
Hikaru Satoh ◽  
Yasuo Nagato
Keyword(s):  
Phase Change ◽  
Structural Characteristics ◽  
Day Treatment ◽  
Vascular Bundles ◽  
Wild Type ◽  
Remarkable Feature ◽  
Juvenile Phase ◽  
Shoot Architecture ◽  
Adult Phase ◽  
In The Wild

We have identified five recessive allelic mutations, mori1-1 to mori1-5, which drastically modify the shoot architecture of rice. The most remarkable feature of mori1 plants is a rapid production of small leaves and short branches. The mori1 plants are about 5 cm in height even 7 months after sowing. No reproductive growth was attained in mori1 plants even if inductive short-day treatment was applied. Leaves of mori1 at any position were very small and the size and shape were comparable to those of the wild-type 2nd leaf. The stem of mori1 7 months after sowing did not differentiate node and internode and had randomly oriented vascular bundles, which were characteristic of the basal part of the wild-type stem where 2nd and 3rd leaves were inserted. These structural characteristics indicate that mori1 maintains the 2nd-leaf stage (juvenile phase) of the wild type. The short plastochron and high cell division activity in the shoot apical meristem further confirmed the juvenility of mori1, corresponding to the 2nd-leaf-differentiation stage in the wild-type embryo. Furthermore, the apparent photosynthetic rate in mori1 leaves was low as in the wild-type 2nd leaf. Thus, mori1 is a heterochronic mutation that suppresses the induction of adult phase and the termination of the juvenile phase. Therefore, MORI1 plays an important role in the juvenile-adult phase change. The importance of heterochronic mutations in modifying shoot architecture is discussed.

scholarly journals Mutants of downy mildew resistance in Lactuca sativa (lettuce).

Genetics ◽  
1994 ◽  
Vol 137 (3) ◽  
pp. 867-874
Author(s):  
P A Okubara ◽  
P A Anderson ◽  
O E Ochoa ◽  
R W Michelmore
Keyword(s):  
Molecular Marker ◽  
Downy Mildew ◽  
Genomic Dna ◽  
Spontaneous Mutation ◽  
Multigene Families ◽  
Downy Mildew Resistance ◽  
Bremia Lactucae ◽  
Wild Type ◽  
Mildew Resistance ◽  
Recessive Mutations

Abstract As part of our investigation of disease resistance in lettuce, we generated mutants that have lost resistance to Bremia lactucae, the casual fungus of downy mildew. Using a rapid and reliable screen, we identified 16 distinct mutants of Latuca sativa that have lost activity of one of four different downy mildew resistance genes (Dm). In all mutants, only a single Dm specificity was affected. Genetic analysis indicated that the lesions segregated as single, recessive mutations at the Dm loci. Dm3 was inactivated in nine of the mutants. One of five Dm 1 mutants was selected from a population of untreated seeds and therefore carried a spontaneous mutation. All other Dm1, Dm3, Dm5/8 and Dm7 mutants were derived from gamma- or fast neutron-irradiated seed. In two separate Dm 1 mutants and in each of the eight Dm3 mutants analyzed, at least one closely linked molecular marker was absent. Also, high molecular weight genomic DNA fragments that hybridized to a tightly linked molecular marker in wild type were either missing entirely or were truncated in two of the Dm3 mutants, providing additional evidence that deletions had occurred in these mutants. Absence of mutations at loci epistatic to the Dm genes suggested that such loci were either members of multigene families, were critical for plant survival, or encoded components of duplicated pathways for resistance; alternatively, the genes determining downy mildew resistance might be limited to the Dm loci.

scholarly journals A splice junction deletion deficient in the transport of RNA does not polyadenylate nuclear RNA.

1983 ◽  
Vol 3 (8) ◽  
pp. 1381-1388 ◽  
Author(s):  
L P Villarreal ◽  
R T White
Keyword(s):  
Simian Virus 40 ◽  
Splice Junction ◽  
Simian Virus ◽  
The Body ◽  
Splice Acceptor Site ◽  
Acceptor Site ◽  
Wild Type ◽  
Normal Position ◽  
Nuclear Rna ◽  
Late Region

A late region deletion mutant of simian virus 40 (dl5) was previously shown to be deficient in the transport of nuclear RNA. This is a splice junction deletion that has lost the 3' end of an RNA leader, an intervening sequence, and the 5' end of the splice acceptor site on the body of the mRNA. In this report, we analyzed the steady-state structure of the untransported nuclear RNA. The 5' ends of this RNA are heterogeneous but contain a prominent 5' end at the normal position (nucleotide 325) in addition to several other prominent 5' ends not seen in wild-type RNA. The 3' end of this RNA does not occur at the usual position (nucleotide 2674) of polyadenylation; instead, this RNA is non-polyadenylated, with the 3' end occurring either downstream or upstream of the normal position.

scholarly journals GENE INTERACTIONS BETWEEN POTASSIUM-SENSITIVE AND POTASSIUM-RESISTANT MUTATIONS OF PARAMECIUM TETRAURELIA

Genetics ◽  
1983 ◽  
Vol 103 (2) ◽  
pp. 153-160
Author(s):  
Donald L Cronkite
Keyword(s):  
High Resistance ◽  
Gene Interactions ◽  
Paramecium Tetraurelia ◽  
Wild Type ◽  
Recessive Mutations ◽  
Resistant Genes ◽  
Type Gene ◽  
Moderately Resistant

ABSTRACT Two unlinked recessive mutations (ks-1 and ks-2) have been induced in Paramecium tetraurelia stock 51. Wild-type survives and grows when up to 30 mm KCl is added to the medium, but the mutants cease to grow and die when added KCl reaches 20-25 m m. These K+-sensitives have been crossed to stocks containing the K+-resistant genes, fA (very resistant) and kA(moderately resistant). All four genes are unlinked. Double mutants of ks-1 and either kA or fA are as resistant as the resistant member of the pair. Doubles of ks-2 and kA are like wild type, and doubles of ks-2 and fA are shifted from high resistance toward wild type. Gene ks-2 acts like a suppressor of kA and fA. This suppression can be understood in terms of the known biochemical defects of the mutants.

scholarly journals RNA Sequencing Reveals Rice Genes Involved in Male Reproductive Development under Temperature Alteration

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 663
Author(s):  
Sudthana Khlaimongkhon ◽  
Sriprapai Chakhonkaen ◽  
Keasinee Tongmark ◽  
Numphet Sangarwut ◽  
Natjaree Panyawut ◽  
...  
Keyword(s):  
High Temperature ◽  
Rna Sequencing ◽  
Reproductive Development ◽  
Yield Reduction ◽  
World Population ◽  
Rice Grain ◽  
Wild Type ◽  
Rice Plants ◽  
Male Development ◽  
Temperature Conditions

Rice (Oryza sativa L.) is one of the most important food crops, providing food for nearly half of the world population. Rice grain yields are affected by temperature changes. Temperature stresses, both low and high, affect male reproductive development, resulting in yield reduction. Thermosensitive genic male sterility (TGMS) rice is sterile at high temperature and fertile at low temperature conditions, facilitating hybrid production, and is a good model to study effects of temperatures on male development. Semithin sections of the anthers of a TGMS rice line under low (fertile) and high (sterile) temperature conditions showed differences starting from the dyad stage, suggesting that genes involved in male development play a role during postmeiotic microspore development. Using RNA sequencing (RNA-Seq), transcriptional profiling of TGMS rice panicles at the dyad stage revealed 232 genes showing differential expression (DEGs) in a sterile, compared to a fertile, condition. Using qRT-PCR to study expression of 20 selected DEGs using panicles of TGMS and wild type rice plants grown under low and high temperature conditions, revealed that six out of the 20 selected genes may be unique to TGMS, while the other 14 genes showed common responses to temperatures in both TGMS and wild-type rice plants. The results presented here would be useful for further investigation into molecular mechanisms controlling TGMS and rice responses to temperature alteration.

INHERITANCE OF RADIATION-INDUCED SPINAL CURVATURES IN THE GUPPY LEBISTES RETICULATUS

1969 ◽  
Vol 11 (4) ◽  
pp. 937-947 ◽  
Author(s):  
Johannes Horst Schröder
Keyword(s):  
Germ Cells ◽  
Vertebral Column ◽  
Segregation Ratio ◽  
X Rays ◽  
Wild Type ◽  
Spinal Curvatures ◽  
Recessive Mutations ◽  
Quantitative Characters ◽  
Radiation Induced ◽  
Lebistes Reticulatus

Hereditary changes in the shape of the vertebral column in Lebistes reticulatus appeared after ancestral irradiation of immature germ cells with 500 or 1000 R of X-rays. Although the mutant to wild-type ratios in the F2 generation after outcrossing fitted a digenic and a trigenic segregation ratio, respectively, the quantitative characters in question are assumed to be caused by recessive mutations of polygenes which are highly mutable.

Characterisation of three shoot apical meristem mutants of Arabidopsis thaliana

Development ◽  
1992 ◽  
Vol 116 (2) ◽  
pp. 397-403 ◽  
Author(s):  
H. M. Ottoline Leyser ◽  
I. J. Furner
Keyword(s):  
Arabidopsis Thaliana ◽  
Root Growth ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Floral Development ◽  
Wild Type ◽  
Recessive Mutations ◽  
Phenotypic Characterisation ◽  
Dicotyledonous Plants ◽  
And Function

The shoot apical meristem of dicotyledonous plants is highly regulated both structurally and functionally, but little is known about the mechanisms involved in this regulation. Here we describe the genetic and phenotypic characterisation of recessive mutations at three loci of Arabidopsis thaliana in which meristem structure and function are disrupted. The loci are Clavata1 (Clv1), Fasciata1 (Fas1) and Fasciata2 (Fas2). Plants mutant at these loci are fasciated having broad, flat stems and disrupted phyllotaxy. In all cases, the fasciations are associated with shoot apical meristem enlargement and altered floral development. While all the mutants share some phenotypic features they can be divided into two classes. The pleiotropic fas1 and fas2 mutants are unable to initiate wild- type organs, show major alterations in meristem structure and have reduced root growth. In contrast, clv1 mutant plants show near wild-type organ phenotypes, more subtle changes in shoot apical meristem structure and wild-type root growth.

The WUSCHEL gene is required for shoot and floral meristem integrity in Arabidopsis

Development ◽  
1996 ◽  
Vol 122 (1) ◽  
pp. 87-96 ◽  
Author(s):  
T. Laux ◽  
K.F. Mayer ◽  
J. Berger ◽  
G. Jurgens
Keyword(s):  
Developmental Stages ◽  
Shoot Meristem ◽  
Wild Type ◽  
Recessive Mutations ◽  
Organ Identity ◽  
Flat Structures ◽  
Meristem Identity ◽  
Wus Gene ◽  
Floral Meristems ◽  
Shoot Meristems

Self perpetuation of the shoot meristem is essential for the repetitive initiation of shoot structures during plant development. In Arabidopsis shoot meristem maintenance is disrupted by recessive mutations in the WUSCHEL (WUS) gene. The defect is evident at all developmental stages and is restricted to shoot and floral meristems, whereas the root meristem is not affected. wus mutants fail to properly organize a shoot meristem in the embryo. Postembryonically, defective shoot meristems are initiated repetitively but terminate prematurely in aberrant flat structures. In contrast to wild-type shoot meristems, primordia initiation occurs ectopically across mutant apices, including the center, and often new shoot meristems instead of organs are initiated. The cells of wus shoot apices are larger and more vacuolated than wild-type shoot meristem cells. wus floral meristems terminate prematurely in a central stamen. Double mutant studies indicate that the number of organ primordia in the center of wus flowers is limited, irrespective of organ identity and we propose that meristem cells are allocated into floral whorl domains in a sequential manner. WUS activity also appears to be required for the formation of supernumerary organs in the center of agamous, superman or clavata1 flowers, suggesting that the WUS gene acts upstream of the corresponding genes. Our results suggest that the WUS gene is specifically required for central meristem identity of shoot and floral meristems to maintain their structural and functional integrity.

Response of soya beans to planting date in south-eastern Queensland. II.* Vegetative and reproductive development

1974 ◽  
Vol 25 (5) ◽  
pp. 723 ◽  
Author(s):  
RJ Lawn ◽  
DE Byth
Keyword(s):  
Seed Yield ◽  
Vegetative Growth ◽  
Growth Period ◽  
Reproductive Development ◽  
Planting Date ◽  
Biological Efficiency ◽  
Vegetative Development ◽  
Planting Dates ◽  
Growing Period ◽  
Seed Yields

Vegetative and reproductive development of a range of soya bean cultivars was studied over a series of planting dates in both hill plots and row culture at Redland Bay, Qld. Responses in the extent of vegetative and reproductive development were related to changes in the phasic developmental patterns. The duration and extent of vegetative development for the various cultivar-planting date combinations were closely associated with the length of the period from planting to the cessation of flowering. Thus, vegetative growth was greatest for those planting dates which resulted in a delay in flowering and/or extended the flowering phase. Similarly, genetic lateness of maturity among cultivars was associated with more extensive vegetative development. Seed yield per unit area increased within each cultivar as the length of the growing period was extended until sufficient vegetative growth occurred to allow the formation of closed canopies under the particular agronomic conditions imposed. Further increases in the length of the period of vegetative growth failed to increase seed yield, and in some cases seed yields were actually reduced. Biological efficiency of seed production (BE) was negatively correlated with the length of the vegetative growth period. Differences in BE among cultivar-planting date combinations were large. It is suggested that maximization of seed yield will necessitate an optimum compromise between the degree of vegetative development and BE. Optimum plant arrangement will therefore vary, depending on the particular cultivar-planting date combination. ___________________ \*Part I, Aust. J. Agric. Res., 24: 67 (1973).

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