title: Small RNAs fromBemisia tabaciAre Transferred toSolanum lycopersicumPhloem during Feeding.
abstract: The phloem-feeding whiteflyBemisia tabaciis a serious pest to a broad range of host plants, including many economically important crops such as tomato. These insects serve as a vector for various devastating plant viruses. It is known that whiteflies are capable of manipulating host-defense responses, potentially mediated by effector molecules in the whitefly saliva. We hypothesized that, beside putative effector proteins, small RNAs (sRNA) are delivered byB. tabaciinto the phloem, where they may play a role in manipulating host plant defenses. There is already evidence to suggest that sRNAs can mediate the host-pathogen dialogue. It has been shown thatBotrytis cinerea, the causal agent of gray mold disease, takes advantage of the plant sRNA machinery to selectively silence host genes involved in defense signaling. Here we identified sRNAs originating fromB. tabaciin the phloem of tomato plants on which they are feeding. sRNAs were isolated and sequenced from tomato phloem of whitefly-infested and control plants as well as from the nymphs themselves, control leaflets, and from the infested leaflets. Using stem-loop RT-PCR, three whitefly sRNAs have been verified to be present in whitefly-infested leaflets that were also present in the whitefly-infested phloem sample. Our results show that whitefly sRNAs are indeed present in tomato tissues upon feeding, and they appear to be mobile in the phloem. Their role in the host-insect interaction can now be investigated.
authors.affiliation: Department of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands.
authors.forename: Paula J M
authors.initials: PJ
authors.lastname: van Kleeff
authors.affiliation: Department of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands.
authors.forename: Marc
authors.initials: M
authors.lastname: Galland
authors.affiliation: Department of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Schuurink
authors.affiliation: Department of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands.
authors.forename: Petra M
authors.initials: PM
authors.lastname: Bleeker
keywords: RNAseq; phloem; small-RNA; tomato; whitefly