In vitro system for studying interactions betweenCitrus exocortis viroidandGynura aurantiaca(Blume) DC. metabolism and growing conditions

Abstract

Citrus exocortis viroid (CEVd) is an economically important plant pathogen, which infects a broad range of hosts. In order to investigate complex interactions among viroid, host-growing conditions, and plant secondary metabolism, we setup an in vitro system for the cultivation of CEVd-infected and viroid-free Gynura aurantiaca (Blume) DC. shoots. Both basal Murashige and Skoog (MS) medium and MS medium supplemented with cytokinines supported the growth of shoots, but viroid-free shoots performed better than infected ones. The addition of cytokinines induced an increase in the concentration of purple-reddish pigment, cyanidin tetraglucoside (GAA), which did not depend on the presence of viroid. The differences in single strand conformation polymorphism patterns between CEVd sequence variants obtained from plants grown on medium supplemented with cytokinines and those obtained from plants grown on basal MS medium or in the greenhouse, indicated that cytokinines may influence not only the plant metabolism, but also the viroid population structure.

Caracterización del Viroide exocortis de los cítricos en diferentes condiciones de indexado

“…The plants grafted with buds infected with CEVd showed symptoms of slight to severe epinasty, leaves wrinkled and twisted to the reverse with light to dark brown cracks in petiole and branches, blisters in the petiole and reduced growth, which coincide with CEVd transmission reports of biotests for C. medica Arizona 861-S plants grown in greenhouses (Bani et al, 2015;Lin et al, 2015a). The use of the crop in vitro in this study proved to be useful to carry out the transmission and development of characteristic CEVd symptoms with an efficiency similar to the in vivo indexing procedures, as reported in other studies for diseases related to viroids in economically important plants Mahfouze et al, 2010;Černi et al, 2012). The presence of symptoms in the samples can simplify the molecular diagnosis of the viroids (Camps et al, 2014) since they distribute themselves homogenously in the plant tissues (Bani et al, 2015;Lin et al, 2015b) and it is difficult to determine is the sampled tissue corresponds to the (Bani et al, 2015;Lin et al, 2015b) y es difícil determinar si el tejido muestreado corresponde al tejido infectado a menos que la expresión de síntomas sirva como indicador.…”

“…The study of the conditions that affect the development of a disease help predict prediction models, find possible weather conditions related to changes, determine the intensity of the disease, establish management measures to reduce the possible effect of the incidence and severity on the field, or to speed up the disease with diagnosis purposes. The development of characteristic symptoms of viroids in economically important plants using in vitro culture has proven to be an effective tool in transmission-related studies Mahfouze et al, 2010;Černi et al, 2012) and diagnosis by indexing (Kapari et al, 2008). Alternative techniques to the official diagnosis by indexing that help understand the behavior of…”

“…El desarrollo de síntomas característicos de viroides en plantas de interés económico mediante el uso de cultivo in vitro ha mostrado ser una herramienta eficaz en estudios relacionados con transmisión Mahfouze et al, 2010;Černi et al, 2012) y diagnóstico por indexado (Kapari et al, 2008). Técnicas alternativas al diagnós-tico oficial por indexado que permitan conocer el comportamiento de los viroides en ambientes controlados pueden ser útiles en el desarrollo de diagnósticos oportunos, la prevención de la enfermedad y el establecimiento de medidas de manejo.…”

“…Las plantas injertadas con yemas infectadas con CEVd presentaron síntomas de epinastia leve a severa, hojas arrugadas y torcidas hacia el envés con grietas de color café claro a oscuro en peciolo y ramas, ampollas en peciolo y crecimiento reducido que concuerdan con reportes de bioensayos de transmisión de CEVd en plantas de C. medica Arizona 861-S desarrolladas en invernadero (Bani et al, 2015;Lin et al, 2015a). El uso del cultivo in vitro en este estudio demostró ser útil para llevar a cabo la trasmisión y desarrollo de síntomas característicos de CEVd con una eficiencia similar a los procedimientos de indexado in vivo, tal como se reporta en otros estudios para enfermedades asociadas a viroides en plantas de interés económico Mahfouze et al, 2010;Černi et al, 2012). La presencia de síntomas en las muestras puede facilitar el diagnóstico molecular de los viroides (Camps et al, 2014) porque se distribuyen de manera heterogénea en los tejidos de…”