ABSTRACT
Leaf laminar growth and adaxial-abaxial boundary formation are fundamental outcomes of plant development. Boundary and laminar growth coordinate the further patterning and growth of the leaf, directing the differentiation of cell types within the top and bottom domains and promoting initiation of lateral organs along their adaxial or abaxial axis. Leaf adaxial-abaxial polarity specification and laminar outgrowth are regulated by two transcription factors, REVOLUTA (REV) and KANADI (KAN). ABA INSENSITIVE TO GROWTH 1 (ABIG1) encodes a HOMEODOMAIN-LEUCINE ZIPPER (HD-ZIP) class II transcription factor and is a direct target of the adaxial-abaxial regulators REV and KAN. To investigate the role of ABIG1 in leaf development and in the establishment of polarity, we examined the phenotypes of both gain-of-function and loss-of-function mutants. Through genetic interaction analysis with REV and KAN mutants, we determined that ABIG1 plays a role in leaf laminar growth as well as in adaxial-abaxial polarity establishment. Genetic and physical interaction assays showed that ABIG1 interacts with the transcriptional TOPLESS corepressor. This study provides new evidence that ABIG1, another HD-ZIP II, facilitates growth through the corepressor TOPLESS.
Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Gene Expression Regulation, Plant , Plant Leaves/metabolism , Transcription Factors/genetics , Transcription Factors/metabolismABSTRACT
BACKGROUND: In Arabidopsis, the genes SHOOT MERISTEMLESS (STM) and CLAVATA3 (CLV3) antagonistically regulate shoot meristem development. STM is essential for both development and maintenance of the meristem, as stm mutants fail to develop a shoot meristem. CLV3, on the other hand, negatively regulates meristem proliferation, and clv3 mutants possess an enlarged shoot meristem. Genetic interaction studies revealed that stm and clv3 dominantly suppress each other's phenotypes. STM works in conjunction with its closely related homologue KNOTTED1-LIKE HOMEOBOX GENE 6 (KNAT6) to promote meristem development and organ separation, as stm knat6 double mutants fail to form shoot meristem and produce a fused cotyledon. RESULTS: In this study, we show that clv3 fails to promote shoot meristem formation in stm-1 background if we also remove KNAT6. stm-1 knat6 clv3 triple mutants result in shoot meristem termination and produce fused cotyledons similar to stm knat6 double mutant. Notably, the stm-1 knat6 and stm-1 knat6 clv3 alleles lack tissue in the presumed region of SAM that is a novel phenotype reported in Arabidopsis mutants. stm-1 knat6 clv3 also showed reduced inflorescence size as compared to clv3 single or stm clv3 double mutants. CONCLUSION: In contrast to previously published data, these data suggest that STM and KNAT6 are redundantly required for the vegetative SAM, but insufficient for the inflorescence meristem.
Subject(s)
Arabidopsis Proteins/genetics , Arabidopsis/growth & development , Arabidopsis/genetics , Gene Expression Regulation, Developmental , Gene Expression Regulation, Plant , Homeodomain Proteins/genetics , Meristem/growth & development , Meristem/genetics , Transcription Factors/genetics , Alleles , Genes, Plant , Heterozygote , Homozygote , Mutation , Phenotype , Plants, Genetically ModifiedABSTRACT
Inflorescence architecture in cereal crops directly impacts yield potential through regulation of seed number and harvesting ability. Extensive architectural diversity found in inflorescences of grass species is due to spatial and temporal activity and determinacy of meristems, which control the number and arrangement of branches and flowers, and underlie plasticity. Timing of the floral transition is also intimately associated with inflorescence development and architecture, yet little is known about the intersecting pathways and how they are rewired during development. Here, we show that a single mutation in a gene encoding an AP1/FUL-like MADS-box transcription factor significantly delays flowering time and disrupts multiple levels of meristem determinacy in panicles of the C4 model panicoid grass, Setaria viridis. Previous reports of AP1/FUL-like genes in cereals have revealed extensive functional redundancy, and in panicoid grasses, no associated inflorescence phenotypes have been described. In S. viridis, perturbation of SvFul2, both through chemical mutagenesis and gene editing, converted a normally determinate inflorescence habit to an indeterminate one, and also repressed determinacy in axillary branch and floral meristems. Our analysis of gene networks connected to disruption of SvFul2 identified regulatory hubs at the intersection of floral transition and inflorescence determinacy, providing insights into the optimization of cereal crop architecture.
Subject(s)
Gene Regulatory Networks , Setaria Plant/genetics , Transcription Factors/metabolism , Flowers/genetics , Flowers/physiology , Inflorescence/genetics , Inflorescence/physiology , Meristem/genetics , Meristem/physiology , Mutation , Plant Proteins/genetics , Plant Proteins/metabolism , Setaria Plant/physiology , Time Factors , Transcription Factors/geneticsABSTRACT
Se evalúo la analgesia con Morfina epidural en 53 pacientes sometidos a cirugía de abdómen alto, abdómen bajo y dolor crónico, utilizando dosis de 4,3 y 2 mgrs. respectivamente, comprobándose la obtención de analgesia de iniciación rápida y de acción muy prolongada. En el primer grupo se valoró la función respiratoria obteniéndose mejoría después de la analgesia. Se observó que la ambulación y movilidad de los pacientes se produjo muy rápidamente en el postoperatório. Los efectos indeseables fueron muy escasos concluyendo que este método es muy efectivo, seguro y exento de complicaciones peligrosas en el manejo del dolor postoperatório y crónico
