Generation of transgenic watermelon resistance to Cucumber mosaic virus facilitated by an effective Agrobacterium-mediated transformation method

Abstract

Watermelon is an annual vegetable crop that suffers from various diseases during growth. Genetic engineering is an effective tool for improving plant disease resistance. This paper presents an effective transformation protocol designed for a female parentwatermelon line mediated by Agrobacterium. In this protocol, 2 times MS Fe-EDTA were supplemented into Murashige and Skoog (MS) medium to suppress the chlorosis during watermelon explants culturing, and the optimal preculture time (5 days) and coculture time (5 days) were screened out to improve the frequency of shoots regeneration. Using our protocol, 17 putative transgenic plants expressing artificial microRNAs that target Cucumber mosaic virus (CMV) 2a/2b genes were recovered, and seven of them were succeeded in obtaining T1 generation seeds because of the technique difficulties of self-pollination of the transgenic watermelon lines. PCR and Southern blot analyses confirmed that the transferred fragment was successfully imported and integrated into the genome of three of these seven transgenic lines. DAS-ELISA assay indicated that the CMV can be detected in the nontransgenic line but not in the transgenic lines, and the transgenic lines displayed resistance to CMV infection.

The major‐effect quantitative trait locus CsARN6.1 encodes an AAA ATPase domain‐containing protein that is associated with waterlogging stress tolerance by promoting adventitious root formation

“…After being bound by EDTA into a metal complex, metal ions remain in solution but exhibit diminished reactivity (Habiba et al ., ). Inhibition of root formation by application of EDTA has been reported in Arabidopsis (Hangarter and Stasinopoulos, ), peach rootstock (Molassiotis et al ., ) and watermelon (Liu et al ., ). Because metal ions are essential for ATP hydrolysis, this may be one of the reasons why the CsARN6.1 Asp protein showed a low ATPase activity with addition of EDTA to the reaction mixture.…”

Progress on Genetic Improvement and Analysis of Bottle Gourd [Lagenaria siceraria (Molina) Standl.] for Agronomic Traits, Nutrient Compositions, and Stress Tolerance: A Review

“…For improving biotic stress tolerance, genetic engineering has potential for developing disease and inspect pest resistant genotypes. Transgenic watermelon lines expressing artificial microRNAs that target Cucumber Mosaic Virus (CMV) 2a/2b genes developed via Agrobacterium mediated-transformation displayed resistance to CMV infection (Liu et al, 2016). A watermelon rootstock named "Gongdae" resistant to Cucumber Green Mottle Mosaic Virus (CGMMV) was developed using Agrobacterium mediated cDNA encoding the CGMMV coat protein gene (CGMMV-CP) (Park et al, 2005).…”

Mapping and Analysis of a Novel Genic Male Sterility Gene in Watermelon (Citrullus lanatus)

“…The seeds of six inbred diploid “Kexi” lines were used as explant material to induce the development of adventitious shoots. Previously described methods were modified for the genetic transformation of watermelon ( Yu et al, 2011 ; Liu et al, 2016 ; Ren et al, 2018 ). Briefly, watermelon seeds were dehusked and sterilized, after which they were sown on basic Murashige and Skoog solid medium and incubated for 2 days in darkness and then 2–3 days with a 16-h light/8-h dark photoperiod.…”