Authors: Julia Rubio Christian Montes Álvaro Castro Catalina Álvarez Blanca Olmedo Marisol Muñoz Eduardo Tapia Fernando Reyes Marcelo Ortega Evelyn Sánchez María Miccono Lorenza Dalla Costa Lucia Martinelli Mickael Malnoy Humberto Prieto
Publish Date: 2014/07/11
Volume: 24, Issue: 1, Pages: 43-60
Abstract
The fungi Botrytis cinerea and Erysiphe necator are responsible for gray mold and powdery mildew diseases respectively which are among the most devastating diseases of grapes Two endochitinase ech42 and ech33 genes and one Nacetylβdhexosaminidase nag70 gene from biocontrol agents related to Trichoderma spp were used to develop a set of 103 genetically modified GM ‘Thompson Seedless’ lines 568 plants that were established in open field in 2004 and evaluated for fungal tolerance starting in 2006 Statistical analyses were carried out considering transgene explant origin and plant response to both fungi in the field and in detached leaf assays The results allowed for the selection of the 19 consistently most tolerant lines through two consecutive years 2007–2008 and 2008–2009 seasons Plants from these lines were grafted onto the rootstock Harmony and established in the field in 2009 for further characterization Transgene status was shown in most of these lines by Southern blot realtime PCR ELISA and immunostrips the most tolerant candidates expressed the ech42–nag70 double gene construct and the ech33 gene from a local Hypocrea virens isolate B cinerea growth assays in Petri dishes supplemented with berry juices extracted from the most tolerant individuals of the selected population was inhibited These results demonstrate that improved fungal tolerance can be attributed to transgene expression and support the iterative molecular and physiological phenotyping in order to define selected individuals from a population of GM grapevinesThis work was funded by the BIOFRUTALES Consortium and the grant INNOVA CHILE 09PMG7229 Authors are grateful to Carlos Muñoz Patricio Hinrichsen Paola Dell’Orto and Mike R Moynihan by their participation in the founding works developing the GM ‘Thompson Seedless’ lines funded by the FONDEF CHILE D01I1064 grant
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