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Andrea Mazzucato - One of the best experts on this subject based on the ideXlab platform.

  • The Occurrence of Seedlessness in Higher Plants; Insights on Roles and Mechanisms of Parthenocarpy
    'Frontiers Media SA', 2019
    Co-Authors: Maurizio E. Picarella, Andrea Mazzucato
    Abstract:

    Parthenocarpy in a broad sense includes those processes that allow the production of seedless fruits. Such fruits are favorable to growers, because they are set independently of successful pollination, and to processors and consumers, because they are easier to deal with and to eat. Seedless fruits however represent a biological paradox because they do not contribute to offspring production. In this work, the occurrence of Parthenocarpy in Angiosperms was investigated by conducting a bibliographic survey. We distinguished monospermic (single seeded) from plurispermic (multiseeded) species and wild from cultivated taxa. Out of 96 seedless taxa, 66% belonged to plurispermic species. Of these, cultivated species were represented six times higher than wild species, suggesting a selective pressure for Parthenocarpy during domestication and breeding. In monospermic taxa, wild and cultivated species were similarly represented. The occurrence of Parthenocarpy in wild species suggests that seedlessness may have an adaptive role. In monospermic species, seedless fruits are proposed to reduce seed predation through deceptive mechanisms. In plurispermic fruit species, Parthenocarpy may exert an adaptive advantage under suboptimal pollination regimes, when too few embryos are formed to support fruit growth. In this situation, Parthenocarpy offers the opportunity to accomplish the production and dispersal of few seeds, thus representing a selective advantage. Approximately 20 sources of seedlessness have been described in tomato. Excluding the EMS induced mutation parthenocarpic fruit (pat), the parthenocarpic phenotype always emerged in biparental populations derived from wide crosses between cultivated tomato and wild relatives. Following a theory postulated for apomictic species, we argument that wide hybridization could also be the force driving Parthenocarpy, following the disruption of synchrony in time and space of reproductive developmental events, from sporogenesis to fruit development. The high occurrence of polyploidy among parthenocarpic species supported this suggestion. Other commonalities between apomixis and Parthenocarpy emerged from genetic and molecular studies of the two phenomena. Such insights may improve the understanding of the mechanisms underlying these two reproductive variants of great importance to modern breeding

  • Table_1_The Occurrence of Seedlessness in Higher Plants; Insights on Roles and Mechanisms of Parthenocarpy.XLSX
    2019
    Co-Authors: Maurizio E. Picarella, Andrea Mazzucato
    Abstract:

    Parthenocarpy in a broad sense includes those processes that allow the production of seedless fruits. Such fruits are favorable to growers, because they are set independently of successful pollination, and to processors and consumers, because they are easier to deal with and to eat. Seedless fruits however represent a biological paradox because they do not contribute to offspring production. In this work, the occurrence of Parthenocarpy in Angiosperms was investigated by conducting a bibliographic survey. We distinguished monospermic (single seeded) from plurispermic (multiseeded) species and wild from cultivated taxa. Out of 96 seedless taxa, 66% belonged to plurispermic species. Of these, cultivated species were represented six times higher than wild species, suggesting a selective pressure for Parthenocarpy during domestication and breeding. In monospermic taxa, wild and cultivated species were similarly represented. The occurrence of Parthenocarpy in wild species suggests that seedlessness may have an adaptive role. In monospermic species, seedless fruits are proposed to reduce seed predation through deceptive mechanisms. In plurispermic fruit species, Parthenocarpy may exert an adaptive advantage under suboptimal pollination regimes, when too few embryos are formed to support fruit growth. In this situation, Parthenocarpy offers the opportunity to accomplish the production and dispersal of few seeds, thus representing a selective advantage. Approximately 20 sources of seedlessness have been described in tomato. Excluding the EMS induced mutation parthenocarpic fruit (pat), the parthenocarpic phenotype always emerged in biparental populations derived from wide crosses between cultivated tomato and wild relatives. Following a theory postulated for apomictic species, we argument that wide hybridization could also be the force driving Parthenocarpy, following the disruption of synchrony in time and space of reproductive developmental events, from sporogenesis to fruit development. The high occurrence of polyploidy among parthenocarpic species supported this suggestion. Other commonalities between apomixis and Parthenocarpy emerged from genetic and molecular studies of the two phenomena. Such insights may improve the understanding of the mechanisms underlying these two reproductive variants of great importance to modern breeding.

  • a tilling allele of the tomato aux iaa9 gene offers new insights into fruit set mechanisms and perspectives for breeding seedless tomatoes
    Molecular Breeding, 2015
    Co-Authors: Andrea Mazzucato, Mondher Bouzayen, Francesco Cellini, Mohamed Zouine, Isabelle Mila, Silvia Minoia, Angelo Petrozza
    Abstract:

    Parthenocarpy is a desired trait in fruit crops; it enables fruit set under environmental conditions suboptimal for pollination, and seedless fruits represent a valuable consumer product. We employed TILLING-based screening of a mutant tomato population to find genetic lesions in Aux/IAA9, a negative regulator of the auxin response involved in the control of fruit set. We identified three mutations located in the coding region of this gene, including two singlebase substitutions and one single-base deletion, which leads to a frame shift and premature stop codon. The transcription of IAA9 was strongly reduced in the frame-shift mutant, and partial loss of mutated protein activity was evidenced by an in vitro transactivation assay. Whereas missense mutations were predicted to be tolerated and did not cause mutant phenotypes, the frame-shift mutation-induced phenotypes expected for a loss of IAA9 function, including altered axillary shoot growth, reduced leaf compoundness and a strong tendency to produce parthenocarpic fruits. Mutant flowers showed pleiotropic anther cone defects, a phenotype frequently associated with Parthenocarpy in tomato and other species. Mutant fruits were larger than those of the seeded control, with higher brix

  • A TILLING allele of the tomato Aux/IAA9 gene offers new insights into fruit set mechanisms and perspectives for breeding seedless tomatoes
    Molecular Breeding, 2015
    Co-Authors: Andrea Mazzucato, Mondher Bouzayen, Francesco Cellini, Mohamed Zouine, Isabelle Mila, Silvia Minoia, Angelo Petrozza, Maurizio E. Picarella, Fabrizio Ruiu, Filomena Carriero
    Abstract:

    Parthenocarpy is a desired trait in fruit crops; it enables fruit set under environmental conditions suboptimal for pollination, and seedless fruits represent a valuable consumer product. We employed TILLING-based screening of a mutant tomato population to find genetic lesions in Aux/IAA9, a negative regulator of the auxin response involved in the control of fruit set. We identified three mutations located in the coding region of this gene, including two singlebase substitutions and one single-base deletion, which leads to a frame shift and premature stop codon. The transcription of IAA9 was strongly reduced in the frame-shift mutant, and partial loss of mutated protein activity was evidenced by an in vitro transactivation assay. Whereas missense mutations were predicted to be tolerated and did not cause mutant phenotypes, the frame-shift mutation-induced phenotypes expected for a loss of IAA9 function, including altered axillary shoot growth, reduced leaf compoundness and a strong tendency to produce parthenocarpic fruits. Mutant flowers showed pleiotropic anther cone defects, a phenotype frequently associated with Parthenocarpy in tomato and other species. Mutant fruits were larger than those of the seeded control, with higher brix

  • characterization of genes controlling stamen identity and development in a parthenocarpic tomato mutant indicates a role for the deficiens ortholog in the control of fruit set
    Physiologia Plantarum, 2008
    Co-Authors: Andrea Mazzucato, Maurizio E. Picarella, Irene Olimpieri, Francesca Siligato, G P Soressi
    Abstract:

    The development of the ovary into a fruit depends on pollination and fertilization. It has been proposed that the restriction of ovary growth before pollination is because of the stamens acting as negative regulators. Accordingly, the silencing of genes responsible for stamen identity has been correlated with Parthenocarpy in different species. The tomato (Solanum lycopersicum L.) parthenocarpic fruit (pat) mutation associates autonomous ovary development with homeotic transformation of the anthers and aberrancy of ovules in the ovary. In this study, we tested the hypothesis that stamen aberrations and Parthenocarpy in pat are driven by cues coming from the altered expression of class B MADS box genes. The data showed that the Pat locus is not allelic to either of the two tomato mutations putatively involved in the B function, stamenless (sl)-2 and pistillate (pi) or to genes encoding class B transcription factors. Whereas pat pi double mutants were not recovered because of tight linkage, pat sl-2 double mutants showed mainly epistatic effects. The developmental regulation of the Sl DEFICIENS (DEF) gene in the wild-type (WT) at anthesis as well as its differential transcription in the pat ovary suggest that it plays a role in the control of ovary growth. Accordingly, when compared with the WT, the gene was also differentially expressed in the parthenocarpic fruit-2 (pat-2) mutant, that is not allelic to pat and has normal ovule development. Altogether the results indicate that in tomato SIDEF plays a role in the control of ovary growth and that the pat mutation is located upstream of this regulatory cascade.

Mondher Bouzayen - One of the best experts on this subject based on the ideXlab platform.

  • a tilling allele of the tomato aux iaa9 gene offers new insights into fruit set mechanisms and perspectives for breeding seedless tomatoes
    Molecular Breeding, 2015
    Co-Authors: Andrea Mazzucato, Mondher Bouzayen, Francesco Cellini, Mohamed Zouine, Isabelle Mila, Silvia Minoia, Angelo Petrozza
    Abstract:

    Parthenocarpy is a desired trait in fruit crops; it enables fruit set under environmental conditions suboptimal for pollination, and seedless fruits represent a valuable consumer product. We employed TILLING-based screening of a mutant tomato population to find genetic lesions in Aux/IAA9, a negative regulator of the auxin response involved in the control of fruit set. We identified three mutations located in the coding region of this gene, including two singlebase substitutions and one single-base deletion, which leads to a frame shift and premature stop codon. The transcription of IAA9 was strongly reduced in the frame-shift mutant, and partial loss of mutated protein activity was evidenced by an in vitro transactivation assay. Whereas missense mutations were predicted to be tolerated and did not cause mutant phenotypes, the frame-shift mutation-induced phenotypes expected for a loss of IAA9 function, including altered axillary shoot growth, reduced leaf compoundness and a strong tendency to produce parthenocarpic fruits. Mutant flowers showed pleiotropic anther cone defects, a phenotype frequently associated with Parthenocarpy in tomato and other species. Mutant fruits were larger than those of the seeded control, with higher brix

  • A TILLING allele of the tomato Aux/IAA9 gene offers new insights into fruit set mechanisms and perspectives for breeding seedless tomatoes
    Molecular Breeding, 2015
    Co-Authors: Andrea Mazzucato, Mondher Bouzayen, Francesco Cellini, Mohamed Zouine, Isabelle Mila, Silvia Minoia, Angelo Petrozza, Maurizio E. Picarella, Fabrizio Ruiu, Filomena Carriero
    Abstract:

    Parthenocarpy is a desired trait in fruit crops; it enables fruit set under environmental conditions suboptimal for pollination, and seedless fruits represent a valuable consumer product. We employed TILLING-based screening of a mutant tomato population to find genetic lesions in Aux/IAA9, a negative regulator of the auxin response involved in the control of fruit set. We identified three mutations located in the coding region of this gene, including two singlebase substitutions and one single-base deletion, which leads to a frame shift and premature stop codon. The transcription of IAA9 was strongly reduced in the frame-shift mutant, and partial loss of mutated protein activity was evidenced by an in vitro transactivation assay. Whereas missense mutations were predicted to be tolerated and did not cause mutant phenotypes, the frame-shift mutation-induced phenotypes expected for a loss of IAA9 function, including altered axillary shoot growth, reduced leaf compoundness and a strong tendency to produce parthenocarpic fruits. Mutant flowers showed pleiotropic anther cone defects, a phenotype frequently associated with Parthenocarpy in tomato and other species. Mutant fruits were larger than those of the seeded control, with higher brix

  • molecular regulation of seed and fruit set
    Trends in Plant Science, 2012
    Co-Authors: Yongling Ruan, Mondher Bouzayen, Sonia Osorio, John Patrick, Alisdair R Fernie
    Abstract:

    Seed and fruit set are established during and soon after fertilization and determine seed and fruit number, their final size and, hence, yield potential. These processes are highly sensitive to biotic and abiotic stresses, which often lead to seed and fruit abortion. Here, we review the regulation of assimilate partitioning, including the potential roles of recently identified sucrose efflux transporters in seed and fruit set and examine the similarities of sucrose import and hydrolysis for both pollen and ovary sinks, and similar causes of abortion. We also discuss the molecular origins of Parthenocarpy and the central roles of auxins and gibberellins in fruit set. The recently completed strawberry (Fragaria vesca) and tomato (Solanum lycopersicum) genomes have added to the existing crop databases, and new models are starting to be used in fruit and seed set studies.

Tohru Ariizumi - One of the best experts on this subject based on the ideXlab platform.

  • Presentation_1_Loss-of-Function of a Tomato Receptor-Like Kinase Impairs Male Fertility and Induces Parthenocarpic Fruit Set.pdf
    2019
    Co-Authors: Hitomi Takei, Yoshihito Shinozaki, Ryoichi Yano, Sachiko Kashojiya, Michel Hernould, Christian Chevalier, Hiroshi Ezura, Tohru Ariizumi
    Abstract:

    Parthenocarpy arises when an ovary develops into fruit without pollination/fertilization. The mechanisms involved in genetic Parthenocarpy have attracted attention because of their potential application in plant breeding and also for their elucidation of the mechanisms involved in early fruit development. We have isolated and characterized a novel small parthenocarpic fruit and flower (spff) mutant in the tomato (Solanum lycopersicum) cultivar Micro-Tom. This plant showed both vegetative and reproductive phenotypes including dwarfism of floral organs, male sterility, delayed flowering, altered axillary shoot development, and parthenocarpic production of small fruits. Genome-wide single nucleotide polymorphism array analysis coupled with mapping-by-sequencing using next generation sequencing-based high-throughput approaches resulted in the identification of a candidate locus responsible for the spff mutant phenotype. Subsequent linkage analysis and RNA interference-based silencing indicated that these phenotypes were caused by a loss-of-function mutation of a single gene (Solyc04g077010), which encodes a receptor-like protein kinase that was expressed in vascular bundles in young buds. Cytological and transcriptomic analyses suggested that Parthenocarpy in the spff mutant was associated with enlarged ovarian cells and with elevated expression of the gibberellin metabolism gene, GA20ox1. Taken together, our results suggest a role for Solyc04g077010 in male organ development and indicate that loss of this receptor-like protein kinase activity could result in Parthenocarpy.

  • Table_1_Loss-of-Function of a Tomato Receptor-Like Kinase Impairs Male Fertility and Induces Parthenocarpic Fruit Set.XLSX
    2019
    Co-Authors: Hitomi Takei, Yoshihito Shinozaki, Ryoichi Yano, Sachiko Kashojiya, Michel Hernould, Christian Chevalier, Hiroshi Ezura, Tohru Ariizumi
    Abstract:

    Parthenocarpy arises when an ovary develops into fruit without pollination/fertilization. The mechanisms involved in genetic Parthenocarpy have attracted attention because of their potential application in plant breeding and also for their elucidation of the mechanisms involved in early fruit development. We have isolated and characterized a novel small parthenocarpic fruit and flower (spff) mutant in the tomato (Solanum lycopersicum) cultivar Micro-Tom. This plant showed both vegetative and reproductive phenotypes including dwarfism of floral organs, male sterility, delayed flowering, altered axillary shoot development, and parthenocarpic production of small fruits. Genome-wide single nucleotide polymorphism array analysis coupled with mapping-by-sequencing using next generation sequencing-based high-throughput approaches resulted in the identification of a candidate locus responsible for the spff mutant phenotype. Subsequent linkage analysis and RNA interference-based silencing indicated that these phenotypes were caused by a loss-of-function mutation of a single gene (Solyc04g077010), which encodes a receptor-like protein kinase that was expressed in vascular bundles in young buds. Cytological and transcriptomic analyses suggested that Parthenocarpy in the spff mutant was associated with enlarged ovarian cells and with elevated expression of the gibberellin metabolism gene, GA20ox1. Taken together, our results suggest a role for Solyc04g077010 in male organ development and indicate that loss of this receptor-like protein kinase activity could result in Parthenocarpy.

  • aberrant stamen development is associated with parthenocarpic fruit set through up regulation of gibberellin biosynthesis in tomato
    Plant and Cell Physiology, 2019
    Co-Authors: Yoshihiro Okabe, Yoshihito Shinozaki, Tohru Ariizumi, Tatsuya Yamaoka, Koichiro Ushijima, Mikiko Kojima, Yumiko Takebayashi, Hitoshi Sakakibara, Miyako Kusano, Sri Imriani Pulungan
    Abstract:

    Parthenocarpy, a process in which fruit set occurs without fertilization, leads to the production of seedless fruit. A number of floral homeotic mutants with abnormal stamen development exhibit parthenocarpic fruit set. Flower development is thought to repress ovary growth before anthesis. However, the mechanism of parthenocarpic fruit development caused by aberrant flower formation is poorly understood. To investigate the molecular mechanism of parthenocarpic fruit development in floral homeotic mutants, we performed functional analysis of Tomato APETALA3 (TAP3) by loss-of-function approaches. Organ-specific promoter was used to induce organ-specific loss of function in stamen and ovary/fruit. We observed increased cell expansion in tap3 mutants and TAP3-RNAi lines during parthenocarpic fruit growth. These were predominantly accompanied by the up-regulation of GA biosynthesis genes, including SlGA20ox1, SlGA20ox2, and SlGA20ox3, as well as reduced expression of the GA-inactivating gene SlGA2ox1 and the auxin signaling gene SlARF7 involved in a crosstalk between GA and auxin. These transcriptional profiles are in agreement with the GA levels in these lines. These results suggest that stamen development negatively regulates fruit set by repressing the GA biosynthesis.

  • the role of ethylene in the regulation of ovary senescence and fruit set in tomato solanum lycopersicum
    Plant Signaling & Behavior, 2018
    Co-Authors: Yoshihito Shinozaki, Hiroshi Ezura, Tohru Ariizumi
    Abstract:

    ABSTRACTFruit set is the developmental transition from ovary to young fruit, and generally requires pollination and fertilization. Although the mechanism for fruit set remains elusive, several lines of evidence have demonstrated that fruit set is triggered by activated metabolism of or increased sensitivity to the plant hormones auxin or gibberellins (GAs), which stimulate cell division and expansion within the ovary. Our recent study with tomato (Solanum lycopersicum) suggested that the gaseous hormone ethylene connects auxin and GA, suppressing initiation of fruit set by down-regulating GA accumulation. By contrast, reduced sensitivity to ethylene triggers accumulation of GA, but not auxin, through increasing bioactive GA biosynthesis and decreasing GA inactivation. These changes induce Parthenocarpy accompanied by pollination-independent cell expansion in the ovary. Here, we provide evidence that ethylene likely promotes mRNA expression of the senescence-associated genes SlSAG12 and SlNAP in unpollinat...

  • Identification and functional study of a mild allele of SlDELLA gene conferring the potential for improved yield in tomato
    Scientific Reports, 2018
    Co-Authors: Yoshihito Shinozaki, Hiroshi Ezura, Kentaro Ezura, Yoshihiro Okabe, Camille Benard, Duyên Prodhomme, Yves Gibon, Tai-ping Sun, Tohru Ariizumi
    Abstract:

    Parthenocarpy, or pollination-independent fruit set, is an attractive trait for fruit production and can be induced by increased responses to the phytohormone gibberellin (GA), which regulates diverse aspects of plant development. GA signaling in plants is negatively regulated by DELLA proteins. A loss-of-function mutant of tomato DELLA (SlDELLA), procera (pro) thus exhibits enhanced GA-response phenotypes including Parthenocarpy, although the pro mutation also confers some disadvantages for practical breeding. This study identified a new milder hypomorphic allele of SlDELLA, procera-2 (pro-2), which showed weaker GA-response phenotypes than pro. The pro-2 mutant contains a single nucleotide substitution, corresponding to a single amino acid substitution in the SAW subdomain of the SlDELLA. Accumulation of the mutated SlDELLA transcripts in wild-type (WT) resulted in Parthenocarpy, while introduction of intact SlDELLA into pro-2 rescued mutant phenotypes. Yeast two-hybrid assays revealed that SlDELLA interacted with three tomato homologues of GID1 GA receptors with increasing affinity upon GA treatment, while their interactions were reduced by the pro and pro-2 mutations. Both pro and pro-2 mutants produced higher fruit yields under high temperature conditions, which were resulted from higher fruit set efficiency, demonstrating the potential for genetic Parthenocarpy to improve yield under adverse environmental conditions.

Angelo Petrozza - One of the best experts on this subject based on the ideXlab platform.

  • a tilling allele of the tomato aux iaa9 gene offers new insights into fruit set mechanisms and perspectives for breeding seedless tomatoes
    Molecular Breeding, 2015
    Co-Authors: Andrea Mazzucato, Mondher Bouzayen, Francesco Cellini, Mohamed Zouine, Isabelle Mila, Silvia Minoia, Angelo Petrozza
    Abstract:

    Parthenocarpy is a desired trait in fruit crops; it enables fruit set under environmental conditions suboptimal for pollination, and seedless fruits represent a valuable consumer product. We employed TILLING-based screening of a mutant tomato population to find genetic lesions in Aux/IAA9, a negative regulator of the auxin response involved in the control of fruit set. We identified three mutations located in the coding region of this gene, including two singlebase substitutions and one single-base deletion, which leads to a frame shift and premature stop codon. The transcription of IAA9 was strongly reduced in the frame-shift mutant, and partial loss of mutated protein activity was evidenced by an in vitro transactivation assay. Whereas missense mutations were predicted to be tolerated and did not cause mutant phenotypes, the frame-shift mutation-induced phenotypes expected for a loss of IAA9 function, including altered axillary shoot growth, reduced leaf compoundness and a strong tendency to produce parthenocarpic fruits. Mutant flowers showed pleiotropic anther cone defects, a phenotype frequently associated with Parthenocarpy in tomato and other species. Mutant fruits were larger than those of the seeded control, with higher brix

  • A TILLING allele of the tomato Aux/IAA9 gene offers new insights into fruit set mechanisms and perspectives for breeding seedless tomatoes
    Molecular Breeding, 2015
    Co-Authors: Andrea Mazzucato, Mondher Bouzayen, Francesco Cellini, Mohamed Zouine, Isabelle Mila, Silvia Minoia, Angelo Petrozza, Maurizio E. Picarella, Fabrizio Ruiu, Filomena Carriero
    Abstract:

    Parthenocarpy is a desired trait in fruit crops; it enables fruit set under environmental conditions suboptimal for pollination, and seedless fruits represent a valuable consumer product. We employed TILLING-based screening of a mutant tomato population to find genetic lesions in Aux/IAA9, a negative regulator of the auxin response involved in the control of fruit set. We identified three mutations located in the coding region of this gene, including two singlebase substitutions and one single-base deletion, which leads to a frame shift and premature stop codon. The transcription of IAA9 was strongly reduced in the frame-shift mutant, and partial loss of mutated protein activity was evidenced by an in vitro transactivation assay. Whereas missense mutations were predicted to be tolerated and did not cause mutant phenotypes, the frame-shift mutation-induced phenotypes expected for a loss of IAA9 function, including altered axillary shoot growth, reduced leaf compoundness and a strong tendency to produce parthenocarpic fruits. Mutant flowers showed pleiotropic anther cone defects, a phenotype frequently associated with Parthenocarpy in tomato and other species. Mutant fruits were larger than those of the seeded control, with higher brix

Isabelle Mila - One of the best experts on this subject based on the ideXlab platform.

  • a tilling allele of the tomato aux iaa9 gene offers new insights into fruit set mechanisms and perspectives for breeding seedless tomatoes
    Molecular Breeding, 2015
    Co-Authors: Andrea Mazzucato, Mondher Bouzayen, Francesco Cellini, Mohamed Zouine, Isabelle Mila, Silvia Minoia, Angelo Petrozza
    Abstract:

    Parthenocarpy is a desired trait in fruit crops; it enables fruit set under environmental conditions suboptimal for pollination, and seedless fruits represent a valuable consumer product. We employed TILLING-based screening of a mutant tomato population to find genetic lesions in Aux/IAA9, a negative regulator of the auxin response involved in the control of fruit set. We identified three mutations located in the coding region of this gene, including two singlebase substitutions and one single-base deletion, which leads to a frame shift and premature stop codon. The transcription of IAA9 was strongly reduced in the frame-shift mutant, and partial loss of mutated protein activity was evidenced by an in vitro transactivation assay. Whereas missense mutations were predicted to be tolerated and did not cause mutant phenotypes, the frame-shift mutation-induced phenotypes expected for a loss of IAA9 function, including altered axillary shoot growth, reduced leaf compoundness and a strong tendency to produce parthenocarpic fruits. Mutant flowers showed pleiotropic anther cone defects, a phenotype frequently associated with Parthenocarpy in tomato and other species. Mutant fruits were larger than those of the seeded control, with higher brix

  • A TILLING allele of the tomato Aux/IAA9 gene offers new insights into fruit set mechanisms and perspectives for breeding seedless tomatoes
    Molecular Breeding, 2015
    Co-Authors: Andrea Mazzucato, Mondher Bouzayen, Francesco Cellini, Mohamed Zouine, Isabelle Mila, Silvia Minoia, Angelo Petrozza, Maurizio E. Picarella, Fabrizio Ruiu, Filomena Carriero
    Abstract:

    Parthenocarpy is a desired trait in fruit crops; it enables fruit set under environmental conditions suboptimal for pollination, and seedless fruits represent a valuable consumer product. We employed TILLING-based screening of a mutant tomato population to find genetic lesions in Aux/IAA9, a negative regulator of the auxin response involved in the control of fruit set. We identified three mutations located in the coding region of this gene, including two singlebase substitutions and one single-base deletion, which leads to a frame shift and premature stop codon. The transcription of IAA9 was strongly reduced in the frame-shift mutant, and partial loss of mutated protein activity was evidenced by an in vitro transactivation assay. Whereas missense mutations were predicted to be tolerated and did not cause mutant phenotypes, the frame-shift mutation-induced phenotypes expected for a loss of IAA9 function, including altered axillary shoot growth, reduced leaf compoundness and a strong tendency to produce parthenocarpic fruits. Mutant flowers showed pleiotropic anther cone defects, a phenotype frequently associated with Parthenocarpy in tomato and other species. Mutant fruits were larger than those of the seeded control, with higher brix