ABSTRACT
We investigated the microRNA172 (miR172)-mediated regulatory network for the perception of changes in external and endogenous signals to identify a universally applicable floral regulation system in ornamental plants, manipulation of which could be economically beneficial. Transgenic gloxinia plants, in which miR172 was either overexpressed or suppressed, were generated using Agrobacterium-mediated transformation. They were used to study the effect of altering the expression of this miRNA on time of flowering and to identify its mRNA target. Early or late flowering was observed in transgenic plants in which miR172 was overexpressed or suppressed, respectively. A full-length complementary DNA (cDNA) of gloxinia (Sinningia speciosa) APETALA2-like (SsAP2-like) was identified as a target of miR172. The altered expression levels of miR172 caused up- or down-regulation of SsAP2-like during flower development, which affected the time of flowering. Quantitative real-time reverse transcription PCR analysis of different gloxinia tissues revealed that the accumulation of SsAP2-like was negatively correlated with the expression of miR172a, whereas the expression pattern of miR172a was negatively correlated with that of miR156a. Our results suggest that transgenic manipulation of miR172 could be used as a universal strategy for regulating time of flowering in ornamental plants.
Subject(s)
Arabidopsis/genetics , Arabidopsis Proteins/metabolism , Cloning, Molecular , DNA, Complementary/metabolism , Flowers/physiology , Gene Expression Profiling , Gene Expression Regulation, Plant , Homeodomain Proteins/metabolism , Lamiales/physiology , MicroRNAs/metabolism , Nuclear Proteins/metabolism , Plants, Genetically Modified/physiology , Plasmids/metabolism , Polymerase Chain Reaction , TransgenesABSTRACT
ResumenLas plantas carnívoras del género Utricularia, capturan un amplio ámbito de organismos acuáticos. La mayoría se desarrollan en ambientes con carencias de nutrientes y tienen la capacidad de cambiar las condiciones de su microambiente. El objetivo de la presente investigación fue estudiar la selectividad, en la captura de zooplancton por Utricularia foliosa en la Ciénaga de Paredes; entre febrero y noviembre 2014. Se determinó si existe selección en los recursos alimentarios de la planta con el índice de Czekanowski y el grado de selección, a través de los índices de Savage e Ivlev. Se estableció la relación existente entre los patrones de captura y selección del zooplancton, con variables físicoquímicas y la disponibilidad de nutrientes en la Ciénaga. En nuestros resultados, el índice de Czekanowski evidenció selección, en los recursos alimentarios de la planta, durante todo el pulso de inundación, con valores entre 0.28 y 0.41. Se encontró selección positiva significativa, con el índice de Savage, para los géneros Lecane sp., Alona sp., Ceriodaphnia sp., y Bosmina sp. (p < 0.05). Se obtuvieron resultados similares, con el índice de Ivlev. La intensidad en la selección de los géneros varió entre periodos hidrológicos y por periodos de aguas altas y bajas. Se identificó que los cambios en la concentración de amoniaco y nitrato, además de la variación en la conductividad eléctrica de la ciénaga influencian la captura que realiza U. foliosa. Este es el primer trabajo que permite dar un acercamiento al entendimiento de la selección de recursos alimentarios dentro de la especie a través de índices de selectividad y uno de los pocos para el género.
Abstract:Utricularia is a genus of carnivorous plants that capture a wide range of aquatic organisms. Most of these plants grow in environments with nutrients deficiency and have the ability to change the conditions of their microenvironment. The aim of this research was to study the selectivity in the zooplankton capture by Utricularia foliosa in the Ciénaga de Paredes. Our study was undertaken between February and November, 2014. We tried to determine if there is selection in the plant's food resources by the Czekanowski's index, and the selection degree by the Savage and Ivlev's indexes. Additionally, we studied the possible relation between the patterns of zooplankton capture and selection, with physicochemical variables in the swamp. The Czekanowski's index showed a food selection in plant resources throughout the flood pulse, with values between 0.28 and 0.41. We also found a significant positive selection with Savage's index for Lecane sp., Alona sp., Ceriodaphnia sp., and Bosmina sp. (p < 0.05); similar results were obtained with Ivlev's index. The intensity in the selection of each captured genus varied significantly between hydrological periods and between high and low water levels in the swamp. It was possible to identify some changes in the ammonia and nitrate concentration and some variability in the electric conductivity of the swamp, which influenced the captures made by U. foliosa. This is the first paper that allows an approach to understand the selection of food resources for the species, using a selectivity index, and one of the few for the genus. Rev. Biol. Trop. 64 (3): 1297-1310. Epub 2016 September 01.