Resumen:
Increased knowledge in disciplines such as Plant Physiology, Genetics and Genomics, along with the development of tools for genome editing (e.g. CRISPR/Cas9), has paved the way for the pursuit of the ideotype, a theoretical model of an archetypal (“ideal”) cultivated plant. In this talk, I will introduce tomato (Solanum lycopersicum) as a model to discuss the ideotype in terms of vegetative and reproductive development, aiming at improving plant productivity and fruit quality. Although the ideotype is the outcome of the integration of multiple factors, it can be accessed through the manipulation of monogenic traits whose physiological effects have already been described. Information for engineering desirable phenotypes can be tapped from two different sources. If the goal is increased yield, superior alleles can be revealed by comparative studies performed in elite cultivars or hybrids. If, on the other hand, the aim is improving stress resistance, the genetic reservoir of inter-fertile wild relatives of crops can be used. In this latter case, monogenic traits of wild relatives can be reproduced in the corresponding crop through introgression (successive backcrosses with a recurrent elite parent) or now using state-of-the-art genome editing techniques, an approach known as “back to nature” breeding (or “re-wilding”). However, traits with a diffuse, polygenic basis, which is frequent in stress resistance, are more difficult to harness. A feasible alternative avenue is de novo domestication of wild relatives. The goal is editing known monogenic determinants of yield in wild relatives to increase fruit yield and palatability. Proof of concept of this approach will be presented for a wild tomato relative.    

Contacto: lazaro.peres@usp.br
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Resumen:
Genetic engineering (GE) broadens the possibilities for making useful genetic changes in crops, but how do GE techniques impact agricultural sustainability?  Not surprisingly, this simple question has a complex and multifaceted answer.  Crops engineered for herbicide tolerance have well-known benefits.  However, they foster a “pesticide treadmill” of continued—possibly even increasing—dependence on herbicides.  Of course, herbicide-tolerant crops also have been created by conventional breeding.  Thus, the challenge to sustainability arises from the herbicide tolerance trait itself, not from the method used to make the genetic change.  In contrast, crops engineered for resistance to infectious diseases and insect pests provide important opportunities to reduce the use of pesticides.  Several examples will be provided, and deployment strategies for improving the durability of genetic traits—GE and conventional—will be discussed.  GE is being used for crop improvement in numerous developing countries.  Such examples demonstrate that publicly funded GE projects can improve food security in ways that address social aspects of sustainability.  It is worth noting that, beyond control of pests and disease, GE is being used to engineer plants to address a wide variety of sustainability challenges. 

Contacto: pvincell@uky.edu
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Resumen:
En Uruguay, el cultivo de frutilla protegido se realiza principalmente en el Litoral Norte (Salto). El mismo se especializa en producción precoz de invierno y principios de primavera utilizando cultivares nacionales de día corto y cultivo protegido por macro y microtúneles plásticos. El oidio, enfermedad causada por el hongo fitopatógeno Podosphaera aphanis, afecta negativamente al cultivo causando pérdidas importantes en calidad del fruto y potencial productivo. Esto lleva al uso frecuente de fungicidas durante la etapa de crecimiento para controlar la enfermedad. El desarrollo de cultivares altamente tolerantes al oidio es un objetivo prioritario del proyecto de mejoramiento genético de frutilla de INIA. En otras especies vegetales, incluidas especies de la familia Rosaceae, se ha reportado que los genes de susceptibilidad MLO (Mildew Locus O) están involucrados en las interacciones planta-oidio y que mutaciones de pérdida de función de los mismos resultan en variedades resistentes a la enfermedad. En este trabajo se realizó la búsqueda in silico de genes MLO en el genoma de Fragaria vesca y se seleccionaron genes candidatos para estudiar sus patrones de expresión en tres genotipos de frutilla cultivada (Fragaria x ananassa) con resistencia diferencial a P. aphanis. Adicionalmente, con el objetivo de tener una visión preliminar del grado de polimorfismos de los genes MLO en los tres genotipos, se secuenciaron las regiones promotoras de los mismos. Los resultados obtenidos aportan información acerca de la interacción molecular planta-patógeno y permiten la identificación de genes que podrían ser responsables de la susceptibilidad a la enfermedad y, por lo tanto, ser utilizados para el desarrollo de cultivares resistentes utilizando selección asistida por marcadores o ingeniería genética. 

Contacto: aarruabarrena@inia.org.uy
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