SLI1 confers broad‐spectrum resistance to phloem‐feeding insects. (5th May 2021)

• Record Type: Journal Article
• Authors: Kloth, Karen J.; Shah, Parth; Broekgaarden, Colette; Ström, Cecilia; Albrectsen, Benedicte R.; Dicke, Marcel
• Is Part Of: Plant, cell and environment. Volume 44:Number 8(2021)
• Page Start: 2765
• Page End: 2776
• Publication Date: 2021-05-05
• Subjects: aphids -- phloem -- plant resistance -- R genes -- whiteflies; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.14064
• Languages: English
• ISSNs: 0140-7791

Abstract

Abstract: Resistance ( R) genes usually compete in a coevolutionary arms race with reciprocal effectors to confer strain‐specific resistance to pathogens or herbivorous insects. Here, we investigate the specificity of SLI1, a recently identified R gene in Arabidopsis that encodes a small heat shock‐like protein involved in resistance to Myzus persicae aphids. In a panel with several aphid and whitefly species, SLI1 compromised reproductive rates of three species: the tobacco aphid M. persicae nicotianae, the cabbage aphid Brevicoryne brassicae and the cabbage whitefly Aleyrodes proletella . Electrical penetration graph recording of aphid behaviour, revealed shorter salivations and a 3‐to‐5‐fold increase in phloem feeding on sli1 loss‐of‐function plants. The mustard aphid Lipaphis erysimi and Bemisia tabaci whitefly were not affected by SLI1. Unlike the other two aphid species, L. erysimi exhibited repetitive salivations preceding successful phloem feeding, indicating a role of salivary effectors in overcoming SLI1‐mediated resistance. Microscopic characterization showed that SLI1 proteins localize in the sieve tubes of virtually all above‐ and below‐ground tissues and co‐localize with the aphid stylet tip after penetration of the sieve element plasma membrane. These observations reveal an unconventional R gene that escapes the paradigm of strain specificity and confers broad‐spectrum quantitative resistance to phloem‐feeding insects. Abstract : We found that the Arabidopsis R gene SLI1 is not strain specific, but affects a wide range of phloem‐feeding insects, including two aphid and a whitefly species, via a phloem‐located mechanism that co‐localizes with the insect stylet tip.