Regeneração de plantas de Carica papaya L. a partir de calos transformados por CRISPR/CAS9 e GATEWAY para resistência ao complexo de vírus da meleira do mamoeiro

Abstract

This work aimed to achieve the complete regeneration of Carica papaya L. plants for resistance to the papaya meleira virus complex from calli transformed with the empty plasmid for control (TGV), for the silencing of the β­1,3­glucanase gene (TBG) through the CRISPR/Cas9 and for the overexpression of the chitinase protein (TQT) through GATEWAY. Callus from TQT transformation showed the best results regarding callus growth and shoot regeneration. White colored and friable type callus showed the highest growth rates and highest number of shoots. Seedlings from TQT transformation showed the best results for stem growth and number of leaves. The survival rate during the developmental stage was 100% for the TQT, 96% for TGV and 92% for TBG. TQT showed the highest number and average length of roots. For TBG transformed plants 80% did not amplify the 941 base pair (Bp) PCR fragment of the β­1,3­glucanase gene, possibly silenced or deleted. None of the TQT transformed plants amplified the GFP reporter gene region. During the stage prior to acclimatization, plants from the TQT transformation had a better development in height and number of leaves. Among the 20 transformed plant TQT ones were the only that did not present infection by PMeV and PMeV2. Only 10% of the TGV transformed plants were infected with PMeV2, while of the TBG transformation plants, 10% were infected with PMeV and 70% with PMeV2.