NEW YORK (GenomeWeb) – Roughly two years after it agreed to pay $518 million for Devgen and its portfolio of agricultural RNAi technologies, Syngenta announced this month that it is collaborating with Australian startup Nexgen to develop virus-resistant crop plants through microRNA targeting.
"Syngenta was attracted to the Nexgen technology due to … the potential to dramatically improve virus resistance characteristics across our breeding programs," Moshe Bar, Syngenta's head of external collaborations, said in a statement. "The collaboration will further strengthen Syngenta's position as a leading developer of crop solutions based on cutting-edge innovations."
The deal also marks the growing interest in miRNAs by major ag-bio firms — among them DuPont, Syngenta, and Monsanto — that have already invested in RNAi.
According to Nexgen, its core technology was developed in the lab of University of Queensland researcher Peer Schenk and can be used to confer viral resistance to existing commercial plant varieties or in parent lines to create hybrid seeds in three ways.
The first involves introducing into plants multiple decoy RNA sequences that interfere with viral miRNAs' ability to bind to host genes involved in pathogen defense. The second entails altering plant genes that are the targets of viral miRNAs in a way that does not affect the open reading frame or the encoded protein, thereby preventing the miRNA from being able to bind to its target without altering the plant's natural gene expression.
The last application of Nexgen's technology involves screening plants for natural variations or mutations in the target region of viral miRNAs, and then using these plants to create resistant lines.
Syngenta and Nexgen said that their arrangement will focus on developing resistance in plants against three unnamed viruses, but a spokesperson for Syngenta declined to offer addition details. However, a 2012 investor presentation by Uniquest, the technology commercialization arm of the University of Queensland, indicates that Nexgen has been investigating maize dwarf mosaic virus, sugarcane yellow leaf virus, and tomato yellow leaf curl virus.
Nexgen officials did not return requests for comment.
Through its deal with Nexgen, Syngenta is building on the foundation it laid through its purchase of Devgen, adding miRNAs alongside RNAi to its suite of gene-regulatory technologies. But it is not alone in this regard.
Monsanto, for instance, has long embraced the agricultural potential of RNAi and has a number of products based on the gene-silencing technology under development including Smart Stax Pro, a Western corn rootworm-resistant strain of corn that expresses widely used Bt proteins along with dsRNA designed to silence a gene essential to the pests. That product is poised for commercialization in the next few years.
Monsanto also recently founded a company called Preceres to develop RNAi-delivery technologies for insect and weed control. But miRNAs have also been on the firm's radar screen for some time, and in early 2013 it bought Rosetta Green, the ag-bio spinoff of miRNA diagnostics firm Rosetta Genomics, for $35 million.
Notably, Rosetta Green had previously attracted the attention of other ag-bios, forming collaborations with DuPont in late 2011 and Bayer CropScience in early 2012 to identify miRNAs involved in drought tolerance. The status of those deals, given the Monsanto acquisition, is not public.
Meanwhile, BASF Plant Science hold a number of patents and patent applications related to the use of both RNAi and miRNAs for crop improvement and pest management.