Genetic and Phenotypic Analyses of Carpel Development in Arabidopsis

NAA is used extensively for fruit thinning of apples to increase fruit size and to promote return bloom. In some cultivars, even if thinning is achieved, fruit size at harvest may be less than expected based on crop load. CPPU, N-(2-chloro-4-pyridinyl)-N.-phenylurea, has been shown to increase fruit growth in apples, grapes, and kiwi. We evaluated combinations of NAA and CPPU on thinning, fruit growth and return bloom in Redchief `Delicious', `Elstar', and `Gloster'. CPPU was applied at 5 mgμL–1 (based on 0 to 10 mgμL–1 response curve) in combination with 15 mgμL–1 NAA as high-volume sprays at 7 to 10 mm KFD. Yield and fruit size distribution (on total yield) were used as index of response. In `Delicious', CPPU (3-year study) increased % large (70 mm+) fruit, but in the presence of NAA % large fruit was reduced 2 of the 3 years. CPPU did not induce significant thinning. There were no significant effects on color or soluble solids; firmness was increased slightly and seed number reduced. The L/D ratio was increased and uneven lobe and carpel development was common. CPPU had no significant effect on return bloom in presence or absence of NAA, but NAA increased bloom in both the presence and absence of CPPU. With `Elstar' (2-year study) there was no significant thinning with either chemical, but CPPU increased mean fruit size and % large (70–80 mm) fruit over nonthinned, but not significantly greater than NAA alone. There were no significant differences in firmness, color, soluble solids or seed number. NAA + CPPU did not inhibit fruit growth or cause excessive uneven carpel development. Frost damage reduced crop load in `Gloster' where results were similar to `Elstar' except seed number was reduced by the NAA + CPPU combination.

Download Full-text

KNAT2: Evidence for a Link between Knotted-like Genes and Carpel Development

The Plant Cell ◽

10.1105/tpc.13.8.1719 ◽

2001 ◽

Vol 13 (8) ◽

pp. 1719-1734 ◽

Cited By ~ 73

Author(s):

V. Pautot

Keyword(s):

Carpel Development

Download Full-text

The Relationship between AGAMOUS and Cytokinin Signaling in the Establishment of Carpeloid Features

Plants ◽

10.3390/plants10050827 ◽

2021 ◽

Vol 10 (5) ◽

pp. 827

Author(s):

Andrea Gómez-Felipe ◽

Daniel Kierzkowski ◽

Stefan de Folter

Keyword(s):

Regulatory Network ◽

Dependent Manner ◽

Mads Box ◽

Type B ◽

Cytokinin Signaling ◽

Reproductive Structures ◽

Carpel Development ◽

Gene Regulatory ◽

The Relationship ◽

Gynoecium Development

Gynoecium development is dependent on gene regulation and hormonal pathway interactions. The phytohormones auxin and cytokinin are involved in many developmental programs, where cytokinin is normally important for cell division and meristem activity, while auxin induces cell differentiation and organ initiation in the shoot. The MADS-box transcription factor AGAMOUS (AG) is important for the development of the reproductive structures of the flower. Here, we focus on the relationship between AG and cytokinin in Arabidopsis thaliana, and use the weak ag-12 and the strong ag-1 allele. We found that cytokinin induces carpeloid features in an AG-dependent manner and the expression of the transcription factors CRC, SHP2, and SPT that are involved in carpel development. AG is important for gynoecium development, and contributes to regulating, or else directly regulates CRC, SHP2, and SPT. All four genes respond to either reduced or induced cytokinin signaling and have the potential to be regulated by cytokinin via the type-B ARR proteins. We generated a model of a gene regulatory network, where cytokinin signaling is mainly upstream and in parallel with AG activity.

Download Full-text

GEG Participates in the Regulation of Cell and Organ Shape during Corolla and Carpel Development in Gerbera hybrida

The Plant Cell ◽

10.1105/tpc.11.6.1093 ◽

1999 ◽

Vol 11 (6) ◽

pp. 1093-1104 ◽

Cited By ~ 73

Author(s):

Mika Kotilainen ◽

Yrjö Helariutta ◽

Merja Mehto ◽

Eija Pöllänen ◽

Victor A. Albert ◽

...

Keyword(s):

Gerbera Hybrida ◽

Carpel Development ◽

Organ Shape

Download Full-text

A CYC-RAD-DIV-DRIF interaction likely pre-dates the origin of floral monosymmetry in Lamiales

10.21203/rs.3.rs-789585/v1 ◽

2021 ◽

Author(s):

Aniket Sengupta ◽

Lena C. Hileman

Keyword(s):

Evolutionary Biology ◽

De Novo ◽

Tomato Fruit ◽

Regulatory Interaction ◽

En Bloc ◽

Regulatory Interactions ◽

Developmental Program ◽

Novel Traits ◽

Carpel Development ◽

Outstanding Question

Abstract BackgroundAn outstanding question in evolutionary biology is how genetic interactions defining novel traits evolve. They may evolve either by de novo assembly of previously non-interacting genes or by en bloc co-option of interactions from other functions. We tested these hypotheses in the context of a novel phenotype—Lamiales flower monosymmetry—defined by a developmental program that relies on regulatory interaction among CYCLOIDEA , RADIALIS , DIVARICATA , and DRIF gene products. In Antirrhinum majus (snapdragon), representing Lamiales, we tested whether components of this program likely function beyond their previously known role in petal and stamen development. In Solanum lycopersicum (tomato), representing Solanales which diverged from Lamiales before the origin of Lamiales floral monosymmetry, we additionally tested for regulatory interactions in this program. ResultsWe found that RADIALIS , DIVARICATA , and DRIF are expressed in snapdragon ovaries and developing fruit, similar to their homologs during tomato fruit development. Additionally, we found that a tomato CYCLOIDEA ortholog positively regulates a tomato RADIALIS ortholog. ConclusionOur results provide preliminary support to the hypothesis that the developmental program defining floral monosymmetry in Lamiales was co-opted en bloc from a function in carpel development. This expands our understanding of novel trait evolution facilitated by co-option of existing regulatory interactions.

Download Full-text

CRABS CLAW and SPATULA, two Arabidopsis genes that control carpel development in parallel with AGAMOUS

Development ◽

10.1242/dev.126.11.2377 ◽

1999 ◽

Vol 126 (11) ◽

pp. 2377-2386 ◽

Cited By ~ 15

Author(s):

J. Alvarez ◽

D.R. Smyth

Keyword(s):

Radial Growth ◽

Genetic Evidence ◽

Longitudinal Growth ◽

Transmitting Tract ◽

The Third ◽

Organ Identity ◽

Carpel Development ◽

Carpel Wall

To help understand the process of carpel morphogenesis, the roles of three carpel development genes have been partitioned genetically. Mutants of CRABS CLAW cause the gynoecium to develop into a wider but shorter structure, and the two carpels are unfused at the apex. Mutants of a second gene, SPATULA, show reduced growth of the style, stigma, and septum, and the transmitting tract is absent. Double mutants of crabs claw and spatula with homeotic mutants that develop ectopic carpels demonstrate that CRABS CLAW and SPATULA are necessary for, and inseparable from, carpel development, and that their action is negatively regulated by A and B organ identity genes. The third carpel gene studied, AGAMOUS, encodes C function that has been proposed to fully specify carpel identity. When AGAMOUS function is removed together with the A class gene APETALA2, however, the organs retain many carpelloid properties, suggesting that other genes are also involved. We show here that further mutant disruption of both CRABS CLAW and SPATULA function removes remaining carpelloid properties, revealing that the three genes together are necessary to generate the mature gynoecium. In particular, AGAMOUS is required to specify the identity of the carpel wall and to promote the stylar outgrowth at the apex, CRABS CLAW suppresses radial growth of the developing gynoecium but promotes its longitudinal growth, and SPATULA supports development of the carpel margins and tissues derived from them. The three genes mostly act independently, although there is genetic evidence that CRABS CLAW enhances AGAMOUS and SPATULA function.

Download Full-text

Temporal Distinction between Male and Female Floral Organ Development in Nicotiana tabacum cv. Xanthi (Solanaceae)

Plants ◽

10.3390/plants9010127 ◽

2020 ◽

Vol 9 (1) ◽

pp. 127

Author(s):

Hongli Chang ◽

Fengjie Sun

Keyword(s):

Nicotiana Tabacum ◽

Molecular Mechanisms ◽

Pollen Grains ◽

Floral Organ ◽

Evolutionary Mechanisms ◽

Tetrad Stage ◽

Flower Primordia ◽

Future Studies ◽

Carpel Development ◽

Solid Foundation

Early floral developmental investigations provide crucial evidence for phylogenetic and molecular studies of plants. The developmental and evolutionary mechanisms underlying the variations in floral organs are critical for a thorough understanding of the diversification of flowers. Ontogenetic comparisons between anthers and pistil within single flowers were characterized over time in Nicotiana tabacum cv. Xanthi. The ages of 42 tobacco flower or flower primordia were estimated using corolla growth analysis. Results showed that the protodermal layer in carpel primordia contributes to carpel development by both anticlinal and periclinal divisions. Periclinal divisions in the hypodermal layer of the placenta were observed around 4.8 ± 1.3 days after the formation of early carpel primordia (ECP) and ovule initiation occurred 10.0 ± 0.5 days after ECP. Meiosis in anthers and ovules began about 8.9 ± 1.1 days and 14.4 ± 1.3 days after ECP, respectively. Results showed an evident temporal distinction between megasporogenesis and microsporogenesis. Flower ages spanned a 17-day interval, starting with flower primordia containing the ECP and anther primordia to the tetrad stage of meiosis in megasporocytes and the bicellular stage in pollen grains. These results establish a solid foundation for future studies in order to identify the developmental and molecular mechanisms responsible for the mating system in tobacco.

Download Full-text