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Abstract BackgroundSoybean gene functions cannot be easily interrogated through transgenic disruption (knock-out) of genes-of-interest, or transgenic overexpression of proteins-of-interest, because soybean transformation is time-consuming and technically challenging. An attractive alternative is to administer transient gene silencing or overexpression with a plant virus-based vector. However, existing virus-induced gene silencing (VIGS) and/or overexpression vectors suitable for soybean have various drawbacks that hinder their widespread adoption. ResultsWe describe the development of a new vector based on cowpea severe mosaic virus (CPSMV), a plus-strand RNA virus with its genome divided into two RNA segments, RNA1 and RNA2. This vector, designated FZ, incorporates a cloning site in the RNA2 cDNA, permitting insertion of nonviral sequences. When paired with an optimized RNA1 construct, FZ readily infects bothNicotiana benthamianaand soybean. As a result, FZ constructs destined for soybean can be first delivered toN. benthamianain order to propagate the modified viruses to high titers. FZ-based silencing constructs induced robust silencing of phytoene desaturase genes inN. benthamiana, multiple soybean accessions, and cowpea. Meanwhile, FZ supported systemic expression of fluorescent proteins mNeonGreen and mCherry inN. benthamianaand soybean. Finally, FZ-mediated expression of the Arabidopsis transcription factor MYB75 causedN. benthamianato bear brown leaves and purple, twisted flowers, indicating that MYB75 retained the function of activating anthocyanin synthesis pathways in a different plant. ConclusionsThe new CPSMV-derived FZ vector provides a convenient and versatile soybean functional genomics tool that is expected to accelerate the characterization of soybean genes controlling crucial productivity traits.
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Enabling the study of gene function in gymnosperms: Virus‐induced gene silencing in Ephedra tweedieana
Abstract PremiseAs the sister clade to angiosperms, extant gymnosperms are crucial for reconstructing ancestral gene regulatory networks in seed plants. This highlights the need for model systems representing each of their distinct lineages. However, tools to quickly and effectively investigate gene function in gymnosperms are still limited due to the challenges of long life cycles and large genome sizes. Species within the xerophytic genusEphedra(Gnetales) have comparatively smaller genomes and shrubby growth habits with shorter life spans, making them better suited for greenhouse cultivation and laboratory experiments. MethodsWe implement virus‐induced gene silencing (VIGS) to manipulate gene expression inEphedra tweedieanaviaAgrobacterium‐mediated vacuum infiltration of tobacco rattle virus (TRV1 and TRV2) into seedlings. ResultsTreatment resulted in highly efficient gene silencing of theE. tweedieana PHYTOENE DESATURASE(PDS) orthologEtwPDS. The expected photobleaching phenotype was observed as early as two weeks, and lasted at least five months in stems, shoot tips, leaves, axillary meristems, and lateral branches of treated plants. DiscussionWe report on virus‐induced targeted gene silencing ofPDSin a Gnetales representative to further enable functional studies of the genetic mechanisms underpinning adaptations in gymnosperms, an important and underrepresented lineage of seed plants.
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- Award ID(s):
- 1911539
- PAR ID:
- 10652421
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Applications in Plant Sciences
- ISSN:
- 2168-0450
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1002/aps3.70027
