Balaji Enugutti

Publications (7) View all

• Article: Microscopic Analysis of Arabidopsis Ovules

  Balaji Enugutti, Kay Schneitz
  Methods in molecular biology (Clifton, N.J.) 01/2013;
• Article: On the genetic control of planar growth during tissue morphogenesis in plants.

  Balaji Enugutti, Charlotte Kirchhelle, Kay Schneitz
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  ABSTRACT: Tissue morphogenesis requires extensive intercellular communication. Plant organs are composites of distinct radial cell layers. A typical layer, such as the epidermis, is propagated by stereotypic anticlinal cell divisions. It is presently unclear what mechanisms coordinate cell divisions relative to the plane of a layer, resulting in planar growth and maintenance of the layer structure. Failure in the regulation of coordinated growth across a tissue may result in spatially restricted abnormal growth and the formation of a tumor-like protrusion. Therefore, one way to approach planar growth control is to look for genetic mutants that exhibit localized tumor-like outgrowths. Interestingly, plants appear to have evolved quite robust genetic mechanisms that govern these aspects of tissue morphogenesis. Here we provide a short summary of the current knowledge about the genetics of tumor formation in plants and relate it to the known control of coordinated cell behavior within a tissue layer. We further portray the integuments of Arabidopsis thaliana as an excellent model system to study the regulation of planar growth. The value of examining this process in integuments was established by the recent identification of the Arabidopsis AGC VIII kinase UNICORN as a novel growth suppressor involved in the regulation of planar growth and the inhibition of localized ectopic growth in integuments and other floral organs. An emerging insight is that misregulation of central determinants of adaxial-abaxial tissue polarity can lead to the formation of spatially restricted multicellular outgrowths in several tissues. Thus, there may exist a link between the mechanisms regulating adaxial-abaxial tissue polarity and planar growth in plants.
  Protoplasma 01/2013; 250(3):651-661. · 1.92 Impact Factor
• Article: Microscopic Analysis of Ovule Development in Arabidopsis thaliana.

  Balaji Enugutti, Maxi Oelschner, Kay Schneitz
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  ABSTRACT: Ovules are the major female reproductive organs in higher plants. In addition, ovules of Arabidopsis thaliana are successfully used as model system to study plant organogenesis. Here we describe two microscopic techniques to analyze Arabidopsis ovule development from the organ to the cellular level in a rapid and reproducible fashion. Both methods are of great value when comparing the morphology of wild-type and mutant ovule development.
  Methods in molecular biology (Clifton, N.J.) 01/2013; 959:127-35.
• Article: Genetic analysis of ectopic growth suppression during planar growth of integuments mediated by the Arabidopsis AGC protein kinase UNICORN

  Balaji Enugutti, Kay Schneitz
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  ABSTRACT: Background The coordination of growth within a tissue layer is of critical importance for tissue morphogenesis. For example, cells within the epidermis undergo stereotypic cell divisions that are oriented along the plane of the layer (planar growth), thereby propagating the layered epidermal structure. Little is known about the developmental control that regulates such planar growth in plants. Recent evidence suggested that the Arabidopsis AGC VIII protein kinase UNICORN (UCN) maintains planar growth by suppressing the formation of ectopic multicellular protrusions in several floral tissues including integuments. In the current model UCN controls this process during integument development by directly interacting with the ABERRANT TESTA SHAPE (ATS) protein, a member of the KANADI (KAN) family of transcription factors, thereby repressing its activity. Here we report on the further characterization of the UCN mechanism. Results Phenotypic analysis of flowers of ucn-1 plants impaired in floral homeotic gene activity revealed that any of the four floral whorls could produce organs carrying ucn-1 protrusions. The ectopic outgrowths of ucn integuments did not accumulate detectable signals of the auxin and cytokinin reporters DR5rev::GFP and ARR5::GUS, respectively. Furthermore, wild-type and ucn-1 seedlings showed similarly strong callus formation upon in vitro culture on callus-inducing medium. We also show that ovules of ucn-1 plants carrying the dominant ats allele sk21-D exhibited more pronounced protrusion formation. Finally ovules of ucn-1 ett-1 double mutants and ucn-1 ett-1 arf4-1 triple mutants displayed an additive phenotype. Conclusions These data deepen the molecular insight into the UCN-mediated control of planar growth during integument development. The presented evidence indicates that UCN downstream signaling does not involve the control of auxin or cytokinin homeostasis. The results also reveal that UCN interacts with ATS independently of an ATS/ETT complex required for integument initiation and they further emphasize the necessity to balance UCN and ATS proteins during maintenance of planar growth in integuments.
  BMC Plant Biology 01/2013; 13(1):2. · 3.45 Impact Factor
• Article: Regulation of planar growth by the Arabidopsis AGC protein kinase UNICORN.

  Balaji Enugutti, Charlotte Kirchhelle, Maxi Oelschner, Ramón Angel Torres Ruiz, Ivo Schliebner, Dario Leister, Kay Schneitz
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  ABSTRACT: The spatial coordination of growth is of central importance for the regulation of plant tissue architecture. Individual layers, such as the epidermis, are clonally propagated and structurally maintained by symmetric cell divisions that are oriented along the plane of the layer. The developmental control of this process is poorly understood. The simple cellular basis and sheet-like structure of Arabidopsis integuments make them an attractive model system to address planar growth. Here we report on the characterization of the Arabidopsis UNICORN (UCN) gene. Analysis of ucn integuments reveals localized distortion of planar growth, eventually resulting in an ectopic multicellular protrusion. In addition, ucn mutants exhibit ectopic growth in filaments and petals, as well as aberrant embryogenesis. We further show that UCN encodes an active AGC VIII kinase. Genetic, biochemical, and cell biological data suggest that UCN suppresses ectopic growth in integuments by directly repressing the KANADI transcription factor ABERRANT TESTA SHAPE. Our findings indicate that UCN represents a unique plant growth regulator that maintains planar growth of integuments by repressing a developmental regulator involved in the control of early integument growth and polarity.
  Proceedings of the National Academy of Sciences 08/2012; 109(37):15060-5. · 9.68 Impact Factor